THE BIOLOGY OF LEARNING OR 'PSYCHOBIOLOGY'   

 

For children growing up in the complex world of the 'global village' an effective philosophical framework or 'paradigm' for educational theory is one based on the knowledge of learning as a natural process. Insights on the physiological mechanisms which underlie the process of natural learning i.e. 'biology of learning' provide evidence  which validates the paradigm of freedom in education... education for the person as a whole i.e. 'holistic education'. Holistic education is the practice of freedom for learning, for creativity and productivity or 'work'. Meaningful work is a function of the natural functioning of the human brain. ("It is now essential to develop educational systems that are truly appropriate for our times." (Gerald Karnow. "Educating the Whole Person for the Whole of Life". Holistic Education Review vol. 5 no. 1 Spring, 1992. 59-64)

                                               

    IMPACT OF BRAIN RESEARCH ON LEARNING THEORY... Education as 'schooling' and traditional teaching methods which emphasize facts and outcomes or 'behavioural objectives' are not compatible with the natural functioning of the brain. They are antagonistic to natural brain functioning or 'brain-antagonistic'. Brain-antagonistic teaching methods  can actually prevent real understanding of meaningful learning and are therefore ineffective in the development of the human potential for creative intelligence required for adaptability. Development of intelligence depends on a learning environment characterised by respect for the individual's 'freedom' and their instinctive responsibility for thir own growth and development and capacity for 'self-evaluation'. Brain-antagonistic teaching  ignores the role of the unconscious or 'emotion' in the learning process which is meaningful because it engages personal initiative based on instinctive motivations or 'emotional drives' i.e. 'intrinsic motivation'. An individual's  type of motivation - 'motivational type' - is determined by the level of psychological development which they have reached ('sociocognitive stage'). Human development is a function of fulfillment of a range of human motives for learning or 'human needs'. These include the  the basic psychological 'ego needs' for security and self-esteem and the so-called 'higher needs'... 'spiritual needs' or  'metaneeds' for self-actualisation and 'ego-transcendance'. Intrinsically motivated learning which engages personality development is a function of natural functioning of the brain. (See http://www.comfsm.fm/socscie/biolearn.htm)

      A fundamental shift is taking place in the philosophical framework or 'paradigm' of education making it possible to conceptualize a teaching methodology which is appropriate for human adaptability to the complexities of the modern world. The attention of educators is being drawn away from the traditional paradigm of the behavioural sciences or 'behaviourism' and shifted towards the new paradigm of systems theory of the science of interconnectedness or wholeness i.e. 'holistic science'. From the perspective of systems theory, it is possible to view the complexity of the learning process as a natural product of brain functioning. Findings of brain research or 'neuroscience' provide new information about the learning process as a function of natural brain processes... the biological basis of the human potential for learning is a natural function of the 'brain/mind'... cognitive functions of the brain learning, remembering etc. can be analysed in terms of physiological mechanisms 'brain functions' involving the propagation and transmission of electrochemical signals or nerve impulses along nerve cells or 'neurons' and across their interconnections... contact points...'synaptic connections' or synapses. This continuity of information or 'information flow' in the brain is the physiological basis of learning... The focal point of the biology of learning is activity at the synapse. Depending on molecular events at the synapse... whether there is an excitatory input which exceeds the inhibitory input... existing synapses can be strengthened, allowing for transmission of electrical impulses from one neuron to the next; they can be weakened, preventing transmission of electrical impulses from one neuron to the next; and they can be  created ('synaptogenesis'). However the synapse is modified, the end result is formation 'neural pathways' ('neural circuits' or 'neural networks'). The brain's capacity to change with learning - 'brain plasticity' or 'neuroplasticity' is largely influenced by environment. Brain development and development of 'intelligence' as 'creative intelligence' depends on environmental conditions which are complex and therefore stimulating because the individual is intrinsically motivated. Intrinsic motivation enhances learning because it enhances the strengthening of existing synaptic connections as well as the formation of new ones. The source of 'intrinsic motivation' for learning is natural curiosity which requires freedom in education.

  "...It is in fact nothing short of a miracle that the modern methods of instruction have not yet entirely strangled the holy curiosity of inquiry; for this delicate little plant, aside from stimulation, stands mainly in need of freedom; without this it goes to wrack and ruin without fail." (Albert Einstein)

    Findings in brain research have significant implications for the improvement of education. They support those principles of learning which are based on learner interest i.e. 'brain-based learning'. Brain-based learning is facilitated by teaching methods which are compatible with brain funcioning i.e. 'brain compatible' pedagogy. (See http://www.21learn.org/arch/articles/caine_principles.html                         

"What is needed is a framework for a more complex form of learning that makes it possible for us to organize and make sense of what we already know about educational theory and methods... Such a framework has to have a 'bottom line' integrity; for us that means it must integrate human behaviour and perception, emotions and physiology. To make our point, we borrow heavily from cognitive psychology, education, philosophy, sociology, science and technology, the new physics, and physiological responses to stress, as well as the neurosciences... The new framework can be created in the link between education and the neurosciences." (Renate Nummela Caine and Geoffrey Caine. Making Connections: Teaching and the Human Brain. page viii)  

 "Learning methods based on the natural functioning of the brain enhance learning because they enhance the formation of synaptic connections between nerve cells. Learning occurs as a result of changing the effectiveness of synapses so that their influence on other neurons also changes. Learning is a physiological function of the brain involving the transmission of signals along nerve cells and across their junctional connections. It is a function of the effectiveness of synapses to propagate signals and initiate or 'fire' new signals along neighboring neurons." (Geoffrey Hinton, "How Neural Networks Learn from Experience," Scientific American, 267:3, September 1992, 145).  

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Subsections                                                                                                                                          homepage

 

founder of neuroscience Ramon y Cajal...  Cajal's study of the architecture of neurons: 'neuron doctrine'...

                         biology of the mind or 'psychobiology'... 

                                 neuron...  

                                          neurons are specialised for the function of communication: morphology of the neuron...

                                         structural components of the neuron.... 

                            neurons 'at rest'... the 'resting cell': properties of the  'semipermeable' cell membrane

                                                            threshold..

                               nerve impulse... 

                                         role of sodium atms in the generation of a nerve impulse... propagation of nerve imlpulse...

The biology of learning is based on the molecular events involved in the propagation of nerve impulses along neurons and their transmission across the points of connection i.e. 'synapses'...   not all signals are transmitted...  they must be sufficiently intense  intense.                                                                                                                            

             the problem of continuity of information in the brain or 'information flow'...  nerve impulses do not jump from one neuron to the next.

                                                       the synapse plays a critical role in information flow...

                                        structure of the synapse ...                                                     

                                                       synaptic theory of transmission of nerve impulses from one neuron to the next across the synapse... 

                                                       molecular events at the synapse... 

                                                       synapse function - binding of neurotransmitters..

                                                       synaptic excitation...  synaptic inhibition...

                                                        continued transmission of impulses across the synapse depends on the effect of binding.

                                                       Learning and the synapse

                                                                                         synapse modification or 'neuroplasticty'...

retention of learning or 'memory'...   notion of localisation of memory as memory trace or 'engram'  

                                                            history of 'search for the engram'                                                                                  

                                                                                                           Karl Lashley and his search for the neural basis of memory or 'search for the engram'

                                                                                                            Donald Hebb inspired research in the development of a new field - psychobiology ('biology of learning')

    molecular activity at synapse as 'memory trace'...

               learning from experience or 'experiential learning' involves memory as the 'process of remembering' a cognitive process...

               Memory as the process of remembering involves the interaction of conscious or 'explicit' memory and unconscious or 'implicit' memory.     

                          learning (and memory) involves emotions..

 

implications for education

knowledge of the role of stimulation on synapse modification is directly related to educational methodology...

..role of emotions

                        so-called 'brain-antagonistic methods of teaching' inhibit experiential learning because they inhibit the formation of new synaptic connections in the cortex of the brain.

                   'brain-based learning'...   'optimalearning'.

                        so-called 'brain-compatible' methods of teaching facilitate the learning process

                  'holistic education'  

     References

 Founder of NEURAL SCIENCE... neuroscience: Ramon y Cajal and the neuron doctrine. (Cajal The Integrative Action of the Nervous System, published 1906) Cajal is considered as the founder of modern brain research. At the end of the nineteenth century it was generally believed that the brain is made up of a continuous net of nerve tissue... 'reticular network' or 'syncitium'. About 100 years ago in Santiago, Spain the great Spanish neuroanatomist Ramon y Cajal  Cajal was the first to suggest that the functions of the brain could be understood by analyzing the functional architecture or 'wiring diagram' of the nervous system. Cajal was the first to study the architecture of the nerve cell or 'neuron'. Cajal carried out his morphological  studies with both adult and embryonic neurons. He applied Golgi's silver staining technique to the morphological study of adult and embryonic nerve tissue and observed that only some cells were stained in their entirety. With this technique, Cajal observed a large variety of nerve cells or 'neurons' - those with short axons communicating with neighbouring cells, those with long axons projecting to other regions of the brain, those with spindle shaped bodies, those with rounded shape cell bodies and those with short branched extensions called 'dendrites'... 'dendritic branching' or 'arbors'. (We know today that it is the diverse nature of the neurons which accounts for the brain's complexity.) Cajal's findings led to the formulation of his 'neuron theory' or 'neuron doctrine' which states that the nervous system is made up of discrete units... isolated unjoined nerve cells or 'neurons'  each one independently living its own biological life... with its independent biological existence rather than a continuous net of nerve tissue or 'syncytium' linked up with hypothetical 'protoplasmic bridges' as was generally believed at the time. It is now known that neurons differ from other cell types as a result of their specialization for neural functions. Cajal described the neuron as an electrically charged or 'polarized' cell with a polarized membrane which produces electrochemical reactions in the form of 'electrochemical signals' or 'electrochemical pulses' or 'nerve impulses'. A nerve impulse is a spike of electrical activity also known as an 'action potential'.  Cajal integrated his knowledge of the action potential into his neuron doctrine. He recognized that the properties of the neuron could be explained in terms of the transduction, conduction and transmission of electrical signals or 'impulses'. As a polarized cell the neuron has the functions of a transducer, conductor and transmitter of electrical impulses all at the same time... converting energy from one form to another. As a transducer the neuron converts or 'transduces' the stimulus energy from the outside world the environmental stimulus energy - into electrical impulses. As a conductor the neuron propagates or 'conducts' the transduced signals from the dendrites to the cell body and then down long unbranched extensions the axons the axon. As a transmitter, the neuron converts the conducted electrical signals into chemical messages and then conveys or 'transmits' them from one neuron to to a neighboring neuron. He deduced that as a polarized cell, the neuron receives  'input signals' on the 'dendrites'... and sends the 'output signals' on long unbranched extensions - the 'axons'. Nerve impulses would travel from the dendrites of a neuron to its cell body and then along its long unbranched extensions - the 'axons' - to the dendrites of the neighboring neuron. This flow of information would be a finite process. With this suggestion Cajal set the stage for a cellular analysis of the 'reflex arc of the spinal cord. English physiologist Charles Sherrington (1861-1952) worked out the details of the reflex arc in the spinal cord of mammals. He described the specialized contact points  between connecting neurons and in 1897 introduced the term 'synapse' derived from the Greek word 'synapto' meaning 'to clasp tightly'.. (The Integrative Action of the Nervous System published 1906). ( 'synapse' ). More than a thousand billion synapses connect the neurons to form  'nerve circuits' or 'neural pathways'.

Since the time of Cajal neuroscience has expanded to include various areas of inquiry... neuroanatomy, neurology, cognitive psychology, psychobiology, neurochemistry....

Although great strides have been made in the neurosciences the question which still remains to be answered is the following: What exactly are the structural and functional changes in the brain that form the basis of learning and the 'retention of learning' or 'memory'?

  The biological basis of the natural learning function of the brain... biology of the mind...or 'psychobiology'. Over the past several decades, the science of the brain or 'neurobiology' or 'neurology' has merged with the science of the 'mind' - 'cognitive psychology' to produce the new field of 'psychobiology' (also known as 'physiological psychology')... bridge between cognitive psychology and molecular biology. Psychobiology is the study of the brain as the physical basis of the 'mind' or 'brain/mind'...  biological substrates of mental functions,of learning or 'cognition'... biology of learning as 'global learning'... a natural function of the brain. The brain is the biological organ of learning with an innate predisposition to search for how things make sense, to search for some meaning of experience. The brain responds to stimuli in the field of focused attention and at the same time absorbs information and signals which are peripheral to the field of focused attention. Many signals perceived peripherally interact with the brain and are processed at the subconscious level  

The aim of research in psychobiology... psychobiological research... the basic problem of psychobiology with the application of biological techniques.. is to to find an explanation to describe the biological or 'neural' mechanisms which underlie functioning of the mind...the basis of mental processes which underlie mental functioning as 'thought', or 'mind'... the  neural basis of the biological basis of mental phenomena such as urges, desires, conscious and subconscious forms of learning, remembering, emotional states and affective states, conscious thought, imagination and creativity... 'neural information'... the mental functions of learning or 'cognition' and the process of acquiring and retaining new knowledge i.e. 'memory'.

The thinking patterns of the mind consist of interrelated processes of remembering and comparing mental data i.e. 'analysis'  and organizing, integrating, evaluating, detecting relationships and making connections i.e. 'synthesis'.  Analysis and synthesis are based on the structural patterns of interconnections 'nerve cells' or 'neurons'. (The number of neurons in the brain - perhaps about 100 billion - is fixed at birth.) Neurons are connected in patterns of  'nerve circuits'... 'neural circuits' ...'neural networks'   ...'neural pathways' throughout the cortex of the brain. The formation of neural pathways results from neuron activity -  propagation of electrical stimuli or 'nerve impulses' along the neurons and the 'two process mechanism' of transmission across their connections between them - specialized points of contact - the 'junctional connections' or 'neural junctions' i.e. 'synapses'. The functions of learning and memory are analysed in terms of cellular and molecular mechanisms... physiological mechanisms or 'neural mechanisms' involving the 'nerve cells' or 'neurons' and their interconnections - the 'synapses'. There are more than a thousand billion synapses in the brain. The most useful strategy for analysis is the so-called 'cellular connection approach' based on the assumption that both the transmission and transformation of neural information and its storage as memory involve only neurons and their interconnections the 'synapses'The synapse is considered as the focal point of learning.  provides a new paradigm for the understanding  of the learning process in terms of the biological substrates underlying the mental functions psychobiology lends a new framework for the study of learning.... this framework is based on the study of biological substrates of mental functions of the brain.. of the process of acquiring new knowledge or 'learning'  and the process of  retaining new knowledge or 'memory'...  are analysed in terms of cellular and molecular mechanisms involving the neurons and their interconnections the synapses... Basic problem of psychobiology: to describe the neural mechanisms which underlie learning and memory. As the study of the learning process, it provides a new framework for educational theory. significant implications for education because they challenge a number of assumptions promoted by the 'worldview' or 'paradigm' of traditional education as 'schooling'. They challenge the notion that the emotional or 'affective' aspect of the learning process is located in different areas of the brain from the processing of information i.e. thinking or 'cognition'. Consequently they challenge the traditionally held assumption that learning does not involve emotions...  but is a matter of 'conditioning'. Conditioned learning depends on forced learning of memorization or 'rote learning'... 'unnatural learning'. Emphasis is on 'content' ... in the form of fragmented information or data which must be learned in order to meet given requirements or 'learning outcomes'. Successful retention of learning is rewarded and failure is punished... with the use of an evaluation system of points or 'grades'. The grading system fosters motivation by mechanisms which are external or 'extrinsic' to the individual's capacity for personal decision-making i.e. 'extrinsic motivation'. The traditional methods are formulated within the paradigm of 'behavioural science' or ''behaviourism. The 'behavioural paradigm' is being seriously questioned today.

"Introducing a new framework for the study of learning, psychobiology is the study of the biological substrates of mental functions. Its aim is to describe the functioning of the mind and the learning process. Its aim is to describe the 'neural' basis of mental phenomena such as urges, desires, conscious and subconscious forms of learning, remembering, emotional states and affective states as well as conscious thought, imagination and creativity. A reconceptualization of the teaching and learning process must be based on the knowledge of brain functioning. Progress in psychobiology has resulted from the application of biological techniques to the study of the biological mechanisms which underlie the mental processes of learning and memory or 'neural information.' They are analysed in terms of mechanisms involving the nerve cells, or 'neural' mechanisms. The most useful strategy for analysis has been the so called 'cellular connection approach.' This approach is based on the assumption that the transmission of neural information and its storage as memory involve only nerve cells and their interconnections". ( Eric Kandel, "Nerve Cells and Behavior", Scientific American 223: 1 July 1970, 281.)

In the new 'cognitive paradigm' new concepts of brain functioning are being applied to teaching techniques which are confluent with the brain's rules for learning or 'brain-based learning'... i.e. 'brain-compatible pedagogies'. The implications for teaching and the role of the teacher... traditional praradigm: 'teacher as instructor'...  cognitive paradigm: 'teacher as facilitator'.

  Since the 1940s techniques have been developed for studying individual neurons.  The new techniques have revolutionized the sciences of the brain  'neuroscience' making it possible to analyze neural processes of increasing complexity. Technology of the 'electron microscope' has made it possible to study individual neurons and to magnify them enough to 'see' how they are connected. There is no evidence of 'protoplasmic bridges' connecting neurons to each other. Instead there are gaps which separate them.  Discovery of the gaps has produced a picture of the brain as a network of single and separate neurons which propagate nerve impulses travelling at varying rates. The problem for neuroscience has been to provide an explanation for information flow along successive neurons when there are gaps which separate them. Investigations with the electron microscope reveal gaps between the neurons...  The gaps are components of the intimate contact points of connection between interconnecting neurons - the 'synapses'This raised the problem... if there are gaps between the neurons then what explains the flow of information in the brain? This is the problem of continuity of information.

  The nerve cell or 'neuron' The brain is made up of single and separate nerve cells or 'neurons'. Neurons are specialized for the function of propagating electrochemical signals or 'nerve impulses' along their unbranched extensions or 'axons'. The diameter of an axon is equivalent to hundredths or thousandths of a hair strand. Nerve impulses are collected from neighbouring neurons through branched extensions or 'dendrites'. They enter the neuronal cell body for processing and are then propagated along... travel at definite rates along axons which split  or 'bifurcate' into thousands of branches which terminate as 'axon terminals' also known as 'synaptic knobs' and 'synaptic buttons'. Axon terminals connect with dendrites of neigbouring neurons at  specialized points of contact known as 'neural junctions', 'synaptic junctions' or 'synapses'. The term 'synapse' was introduced in 1897 by C.S. Sherrington and is derived from the Greek word 'synapto' meaning 'to clasp tightly'.

 The number of nerve cells in the brain is fixed at birth and no new nerve cells grow and develop. Learning and experience change the structure of the neural networks. Learning is a function of stimuli strong enough to influence the effectiveness of synapses in the transmission of signals from one neuron to another across the synaptic clefts. It is a function of the effectiveness of synapses to propagate signals and initiate or 'fire' new signals along neighboring neurons. Those teaching and learning methods which inhibit learning inhibit the formation of connections between nerve cells, the 'synapses'.

The characteristic features of neurons are specifically adapted for cell communication and the transmission of electrical impulses or 'nerve impulses' which travel along their axons. The transmission of nerve impulses from one neuron to another involves the binding of receptor molecules with neurotransmitter molecules on the membrane .

Neurons are specialised for the function of communication: morphology of the neuron The central bulb of the neuron - the 'cell body' or 'soma' - contains the nucleus and its enclosed genetic material. Branched extensions of the soma are the structural pathways for incoming nerve impulses... 'dendrites'. Projections along the http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtmldendritic branches - the 'dendritic spines' - are outgrowths through which nerve impulses are transmitted from neigboring cells. They carry the 'input signal' into the cell body. The structural pathway for the transmission of the 'output signal' is the long unbranched extension from the soma - the 'axon'. Axons  extend from the soma over varying distances and then bifurcate several times giving rise to smaller branches and their expanded terminals - the 'axon terminals' or 'synaptic knobs' or 'synaptic buttons'. These make contact with neighboring cells at specialised contact points which function in the transmission of nerve impulses - the 'synapses'.  Each neuron has hundreds or even thousands of synapses on its surface.

Structural components of the neuron. Neurons have the same basic structural components as other cell types: The 'nucleus' contains genetic material DNA (deoxyribonucleic acid) which directs the cell's activities. The 'cytoplasm' outside the nucleus is made up of a structural framework - 'endoplasmic reticulum' - within which are located a variety of functional units or 'organelles'. The 'mitochondria' - the 'powerhouses' of the cell contain enzymes and substrates for the breakdown of glucose molecules in the production of energy rich ATP molecules (adenosinetriphosphate). The stored energy is released in the 'ribosomes' - organelles located throughout the interior of the cell. Ribosomes contain the enzymes and substrates for the synthesis of macromolecules or 'protein synthesis'. Cell specific proteins are produced and packaged into 'vessicles' in the Golgi bodies and then travel to the functional boundary of the cell or 'cell membrane'. The membrane surrounds the entire cell including the soma, the axon with its branches and terminals, and the dendrites with their branches and spines. The membrane is described as 'semipermeable' because it is permeable to some substances and not to others thus regulating the exchange of molecules between the interior of the cell and the exterior. The property of semipermeability is a function of the activity of pores or 'channels' which can open and close their 'gates' to allow the passage of certain atoms, ions and molecules. Chemical 'receptor molecules' which project from the outer surface of the cell membrane recognize and bind to specific chemical substances approaching the cell membrane such as 'neurotransmitters' involved in the transmission of nerve impulses from one neuron to the next i.e. 'information flow'.

"There are perhaps about one hundred billion neurons, or nerve cells, in the brain, and in a single human brain the number of possible inter-connections between these cells is greater than the number of atoms in the universe." (Robert Ornstein and Richard Thompson, The Amazing Brain. Boston: Houghton Mifflin Company. 1984, 21) T

 All neurons transmit information in the form of electrochemical reactions which travel along their axons i.e. electrochemical pulses or 'nerve impulses'.

Neurons 'at rest'... the 'resting cell': properties of the  'semipermeable' cell membrane which is permeable to some substances and not to others.the 'semipermeable' cell membrane inhibits the easy access of sodium ions to the cell interior. A nerve cell or 'neuron' which is not carrying a nerve impulse is said to be in the 'resting state'... 'at rest'. It is a 'resting cell'. A resting cell is characterised by a specific difference in chemical composition. This difference is manifest as difference in electric charge on either side of the membrane - positive on the outside and negative on the inside - resulting from the chemical properties of 'sodium atoms' which play a key role in the generation of an  electrochemical reaction known as the action potential or nerve impulse. The telectrically neutral sodium atoms (Na) containing the same number of negatively charged electrons as positively charged protons. They function as positively charged 'sodium ions' (Na+) which are prevented from moving across the membrane of the resting as a result of its semipermeability.  An active sodium pump (active because it requires energy - ATP molecules) keeps them from moving through the special pores... 'sodium channels' or sodium gates'  across the membrane from the outside to the inside with the 'gradient'. the 'sodium gates' are closed. Positive potassium ions are kept on the outside of the membrane by way of a 'potassium pump'. In addition negative chloride ions (derived from the salt molecule) are pumped to the inside. As a result of the inhibition of easy access of sodium ions to the cell interior the intracellular cytoplasm of the resting state remains negatively charged compared to the tissue fluid outside the cell, the 'extracellular fluid.' The extracellular concentration of sodium ions is ten times greater than the intracellular concentration. The result is a difference in voltage across the membrane, a 'differential voltage' which measures 70 millivolts, nearly a tenth of a volt. This differential voltage or 'gradient' of -70 millivolts is called the 'resting membrane potential' which is maintained through the constant action of the sodium and potassium pumps. Despite the gradient, positive sodium ions are prevented from moving towards the cell interior.

 The nerve impulse as electrochemical pulse... initiation or  generation of  'action potential'...spike of electrical activity... and conduction... propagation of nerve impulse along the neuron

 Role of sodium atoms in the generation of a nerve impulse The energy source and the signal source for each neuron is the electrially charged sodium ion - a derivative of the electrically neutral sodium atom. In the sodium atom, the number of negatively charged electrons orbiting the nucleus is equal to the number of positively charged protons within the nucleus. The sodium atom gains positive electric charge when combined with chlorine atoms in salt crystals. Chloride ions (Cl-) are negatively charged. Sodium ions (Na+) are positively charged. Potassium ions (K+) are positively charged. In the resting cell, the concentration of positively charged sodium ions in the tissue fluid (outside the cell membrane ('extracellular' concentration) is ten times greater than the concentration of sodium ions in the cytoplasm  on the inside of the cell ('intracellular' concentration). On the inside of the nerve fibre in its resting state there are more negatively charged chloride ions (Cl-) than positively charged sodium (Na+) and potassium ions (K +). Consequently the inside of the nerve fiber is negatively charged. The concentration of chloride ions inside the cell - 'intracellular concentration - is greater than the concentration of chloride ions on the outside of the cell - extracellular concentration. On the outside of the nerve fibre in its resting state there are more positively charged sodium (Na+) and potassium (K+) ions than negatively charged chloride ions (Cl-). Consequently the outside of the nerve fiber is positively charged. As a result, the intracellular cytoplasm is negatively charged compared to the tissue fluid outside the cell,  the extracellular fluid.  The negative voltage... difference in voltage across the membrane...  The inside is negative relative to the outside. The result is a difference in voltage across the membrane, a 'differential voltage.' Measuring 70 millivolts, nearly a tenth of a volt, this differential voltage or ''voltage gradient' of -70 millivolts is called the 'resting membrane potential.'  Despite the gradient, positive sodium ions are prevented from moving towards the cell interior as a result of the 'semipermeability' of the cell membrane which inhibits the easy access of sodium ions to the cell interior. Special pores for the passage of sodium ions across the membrane, the 'sodium gates,' are closed in the resting cell. This semipermeability of the cell membrane prevents sodium ions from moving across the membrane to the negatively charged cytoplasm of the resting cell. The inside of the nerve fibre in its resting state remains negatively charged.

 The 'semipermeable membrane' of the neuron is acted upon by the three forces: first the tendency of ions to move from areas of high charge or 'voltage' to areas of low voltage... 'electrical gradient'; second the tendency of ions to move from areas of high concentration to areas of low concentration... 'concentration gradient'; and third the 'sodium-potassium pump' which prevents the sodium ions from moving across the membrane to the cell interior by closing the special pores or 'sodium gates'. In this way the intracellular cytoplasm remains negatively charged.The special properties of the cell membrane give rise to electrochemical reactions described as 'electrochemical pulses' or 'electrical impulses'.

  The electric charge on one nerve impulse is about one tenth of one volt (has an amplitude of 100 millivolts) and a duration of one millisecond (thousandth of a second) during which time the influx of sodium ions ceases.  At a critical point called the 'threshold,' the inside of the cell becomes positive with respect to the outside. Sodium ions cease to move across the membrane  In about one millisecond, ta new ionic balance is created and the 'differential voltage returns to the resting membrane potential value of -70 millivolts. A new ionic balance is created and the 'differential voltage' returns to the resting state value of -70 millivolts. In this way, nerve impulses or 'signals' are transmitted along nerve cells throughout the brain.

 Nerve impulses are initiated by incoming  chemical stimuli or 'excitatory signals' which decrease the 'membrane potential', ('voltage gradient')  and depolarize the membrane creating an 'action potential'. The depolarization of the membrane increases its permeability to the positively charged sodium ions on the outside of the membrane. The sodium gates open creating a flux of ions across the membrane  ...the positively charged sodium ions rush inwards across the membrane into the cytoplasm of the interior of the cell while potassium ions rush outwards to the exterior of the cell. when the interior of the cell becomes positive with respect to the exterior ... a spike of electrical activity... the 'action potential'... marks the generation of a nerve impulse. With the influx of sodium ions and the efflux of potassium ions the voltage gradient is decreased and the membrane is further depolarized. The influx of sodium ions and the efflux of potassium ions decreases the voltage gradient further depolarizing the membrane. As a result, the neighboring sodium gates open increasing the permeability to sodium ions. They rush across the cell membrane into the interior cytoplasm of the neuron. The resulting depolarization of the membrane increases its permability to other sodium ions and so on in a sequential fashion throughout the length of the axon. The sequential inrush of sodium ions from one point of the membrane to the next is the process which constitutes transmission of the nerve impulse along the axon.

When an incoming physical or chemical stimulus or 'excitatory signal' reaches a nerve cell, the voltage gradient or 'membrane potential' is decreased and the membrane is depolarized. With the depolarization of the membrane, there is an increase in its permeability to sodium ions on the outside of the membrane. The sodium gates open and the positively charged sodium ions rush into the cytoplasm of the interior of the cell(influx). At the same time potassium ions rush outwards to the exterior of the cell(efflux). This marks the generation of a nerve impulse. The influx of sodium ions and the efflux of potassium ions decreases the voltage gradient further depolarizing the membrane and incresing its permeabiity to other sodium ions.The neighboring sodium gates are opened resulting in increased permeability to sodium ions. They rush into the cell interior, depolarizing the membrane and increasing its permability to other sodium ions and so on in a sequential fashion throughout the length of the axon.  The sequential inrush of sodium ions into the interior of the neuron from one point of the membrane to the next is the process which constitutes action potential  or nerve impulse.

 Physical manifestation of the nerve impulse... electrical impulse action potential refers to the flux of ions across the membranes of nerve cells- is the result of an electrochemical reaction which is a function of the special properties of the cell membrane sodium ions rush inwards across the membrane to the interior of the cell - influx - and potassium ions rush outwards to the exterior of the cell- efflux. The membrane potential is rapidly changed and a new ionic balance is created. The change in membrane potential is the basis of the action potential. .

The transmission of nerve impulses from one neuron to another occurs at the junction between neurons, the specialized contact points known as 'synapses.'

Their transmission is primarily involved with the movement of sodium ions into the interior of the cell.  Incoming signals are collected from other neurons through dendrites. They enter the cell body for processing and are sent outwards through the axon which bifurcates at many points giving rise to numerous 'axon terminals.' At the synaptic junction between neurons, signals pass from the synaptic knob of one neuron and are propagated across the synaptic cleft to the contact point on the connecting neuron. Signals reach the synapse as bursts of electrochemical pulses - so many per second. These do not jump from one neuron to the next. The electrical code of transmission is first  changed into the chemical code of transmission. The arrival of electrochemical pulses at the synapse triggers the release of specialized neural transmitter molecules, known as 'neurotransmitters.' These are contained in small vesicles located in the synaptic knob. They are releasedthrough the presynaptic membrane and are propagated across the synaptic cleft. They attach to special receptor binding sites on the postsynaptic membrane. Their binding triggers a change in the membrane permeability of the connecting neuron. The binding is excitatory if it causes the movement of electrically charged ions and results in the depolarization of the membrane. A new action potential is generated and the nerve impulse is transmitted.The binding is inhibitory if it results in the further polarization of the membrane. The generation of a new action potential is inhibited and the nerve impulse is not ransmitted.  

 The voltage of an action potential is measured in thousandths of volts - 'millivolts'. A small pocket flashlight battery could energize five thousand action potentials... amplitude and  speed of the action potential is related to the length and the diameter of the conducting nerve. Small fibers conduct impulses slowly. Large fibers conduct impulses rapidly. Action potentials of small fibers are smaller and wider than action potentials of large fibers.

 The nerve impulse  is an electrochemical pulse or 'signal' ... a region of charge reversal travelling along the neron... involvies ionized atoms of chlorine, sodium and potassium - negatively charged 'chloride ions' (Cl-), positively charged sodium ions (Na+) and positively charged potassium ions (Ka+)... travelling along the nerve fiber or 'axon'.

 Communication between one neuron and the next takes place in the form of transmission of nerve impulses across the synapse    Messages are sent from one neuron to another by way of electrochemical pulses - a few at a time or in bursts of up to a thousand per second. Nerve impulses are collected from other neurons through the dendrites. The impulses are sent through the axons which split into thousands of branches. At the end of each branch is the point of connection with dendrites of another neuron - the 'synapse'. At the synapse the signals are transmitted from one neuron to the next across their interconnections. First the electrical activity from the axon is converted to chemical activity which either inhibits or excites activity in the connecting neuron, depending on the intensity of the signal. An electrical impulse from one axon is transmitted to the dendrites of the next neuron if the excitatory input is greater than the inhibitory input. The transmission of nerve impulses to neigbouring neurons is the result of a 'biophysical process' which takes place at the synapse... More than a thousand billion synapses connect the neurons to form  'nerve circuits' or 'neural pathways'.

Recent brain research findings indicate that the synapse or neural junction is involved in the transmission of nerve impulses from one neuron to another. The two processes, synaptic inhibition and synaptic excitation are instrumental in the formation of nerve circuits and networks in the brain. The functioning of the brain involves this 'two process mechanism' as well as the mechanism of transmission of nerve impulses along nerve cells.Learning is a natural function of the brain. It involves the transmission of signals along nerve cells and in addition the two process mechanism of signal transmission across their junctional connections, the synapses. The networks of the brain are a function of the activity of nerve cells and their functional junctions, the synapses. No new nerve cells develop in the human brain after birth. Modification of brain tissue occurs in the synapses. Synapse is a neural junction. "The unit of analysis for brain function has classically been the neuron." The neural junction is involved in the transmission of nerve impulses. Called the 'junctional mechanism' or 'two process mechanism' involving both neurons and their junctions. Neural modifiability and memory mechanisms: Search for the engram: The most basic property of the nervous system is its 'time-binding' function - capacity for learning and memory. "It is in the junctional mechanism that long lasting modifications of brain tissues must take place. Although adult nerve cells do not divide, a mechanism of permanent modification of brain tissue does display many of the properties of the mechanism of differentiation of embryonic tissue. Experientially initiated guided growth of new nerve fibers does take place and alters the spatial pattern of junctional relationships among neurons. Long term memory therefore becomes more a function of junctional structure than of strictly neural (nerve impulse generating) processes." (47) New synapses grow and develop. Experience can cause new synapses to grow. learning can cause new synapses to form and grow. Learning involves a change in the effectiveness of a synapse which causes a change in the influence of one neuron on another. Learning is a function of the point of connection between two neurons.

 Until the recent findings of brain research, the unit of analysis for the functioning of the brain has been the neuron. Freud called the cell-to-cell junctions between the nerve cells 'contact barriers'. Recent findings in brain research indicate that the neural junction is involved in the transmission of nerve impulses from one neuron to another. The transmission of nerve impulses from one neuron to another occurs at the junction between neurons, the specialized contact points known as 'synapses.' (John Carew Eccles, The Physiology of Nerve Cells, Baltimore: Johns Hopkins Press 1957)

Nerve impulses are transmitted from one neuron to another at specialized contact points known as 'synapses.' The synapse is the point of junction between two neurons. Synapse is a neural junction. More than a thousand billion synapses in the brain.

 Nerve impulses do not jump from one neuron to the next....  role of neurotransmitters... Their transmission across the synapse is not simply a matter of jumping across the synaptic cleft. They are first translated into... converted into... corresponding chemical messages. The arrival of a electrochemical pulses nerve impulse at the synapse  triggers an increase in permeability of the membrane to calcium ions which rush into the interior of the neuron and combine with molecules of the protein 'calmodulin'. The resulting calcium-calmodulin complex produces a specific physiological response... powerful metabolic activity which activates the release of large numbers of specialized chemical transmitter molecules - 'neural transmitter molecules' or 'neurotransmitters' (acetylcholine, endorphin, enkephalin, epinephrine, norepinephrine, glutamate, glycine, serotonin, oxytocin, histamine, vasopressin,dopamine, dynorphin, aspartate, gaba). Neurotransmitters are synthesized, packaged and stored in small 'synaptic vesicles' located in the synaptic knob of the pre-synaptic neuron. When the appropriate electric signal arrives,  the transmitter molecules are released through the presynaptic membrane... travel from the synaptic vesicles in the 'synaptic knob' and are released through the presynaptic membrane of the axon terminal into the fluid-filled 'synaptic space' or 'synaptic cleft'. They are propagated across the synaptic cleft to the post-synaptic membrane of the connecting neuron. They attach or 'bind' to special receptor binding sites on the postsynaptic membrane and their binding triggers a change in the membrane permeability of the connecting neuron.

Not all signals are transmitted from one neuron to an adjacent neuron. Whether or not they generate a new impulse depends on the nature of their binding to the membrane of the connecting neuron.

Nerve impulses which reach the synapse are subjected to one of two synaptic processes: synaptic excitation or synaptic inhibition. Depending on the process occurring at the synapse, an incoming signal is transmitted to the connecting neuron and fired or not fired. A signal crossing the synapse can have one of two effects: it can have an excitatory effect by lowering the threshold for firing the signal; it can have an inhibitory effect by raising the threshold for firing the signal. The stronger the stimulus, the more pulses are generated. Depending on the number of pulses generated, they initiate or inhibit the 'firing' of new signals along the connecting neuron. Depending on the specific properties of the signal, its electrical effects either inhibit or excite activity in the connecting neuron. The continued transmission of the signal can be either inhibited or enhanced. If the inhibitory input exceeds the excitatory input then a connection is not made between one neuron and the next. If the excitatory input exceeds the inhibitory input then transmission is enhanced and a connection is made between one neuron and the next.

  The problem of continuity of information in the brain or 'information flow'. The term information flow'  refers to the propagation of electrical signals or 'nerve impulses' along nerve cells or 'neurons' and their transmission across their interconnnections or 'synapses'.

Recent findings in brain research suggest that  it is possible to understand the functioning of the brain once there is sufficient explanation for the specific functions of individual neurons in the generation and propagation of nerve impulses and their transmission across the synapses. Communication between one neuron and the next takes place in the form of transmission of nerve impulses at the synapse.

Nerve impulses are electrical messages collected from neighbouring neurons through the dendrites. They enter the neuronal cell body for processing and are then transmitted along the axons which split or bifurcate into thousands of branches giving rise to 'axon terminals'. Axon terminals connect with dendrites of neigbouring neurons at the points of contact - the 'synapse'. At the synaptic junction between neurons, signals pass from the synaptic knob of one neuron and are propagated across the synaptic cleft to the contact point on the connecting neuron.The synapse plays a critical role in the transmission of impulses from one neuron to the next.  Not all signals are transmitted from one neuron to an adjacent neuron.

At the synapse, activity from the axon is converted to electrical stimuli that inhibit or excite activity in the connecting neuron. An electrical impulse from one axon is transmitted to the dendrites of the next neuron if the excitatory input is greater than the inhibitory input. As a result of ...depending on... synaptic activity (transmission of nerve impulses)... molecular events at the synapse...  lead to the formation of 'neural circuits'... 'neural networks'... 'neural pathways'. Neural pathways can be altered with the creation of new synapses and with the strengthening or weakening 'modification' of existing synapses in a process of 'synapse modification'. Synapse modification is the focal point of investigation into the physiological process of continuity of information or 'information flow' ias the basis for 'learning' and the 'retention of learning' or 'memory'.

For a long time it was believed that information flow was a purely electrical phenomenon because the transmission of impulses from one neuron to another is so fast. Up until the 1940s the problem of information flow was approached in terms of analysis of the neuron because it was believed to be simply a function neural processes involved in the generation and propagation of nerve impulses along the neurons. Neurons would be connected to each other by junctions or bridges of protoplasm... the hypothetical 'protoplasmic bridges' which would solve the problem of continuity and the unimpeded flow of information in the brain.

Each of the millions of single neurons in the brain has a separate biological existence. The separate neurons are connected to each other by way of more than a thousand billion synapses to form the various nervecircuits or 'neural pathways'. Neural pathways can be altered with the creation of new synapses and with the strengthening or weakening of existing synapses in a process of 'synapse modification'. Synapse modification is the biological basis for the process of forming neural networks or 'learning'. Learning involves the generation of nerve impulses at the synapse, their propagation at definite rates along the axons of neurons and their transmission across the synaptic clefts.    It explains the mechanism... series of molecular events involved in the... transmission... transformation of neural information as it travels from one neuron to a connecting neuron across the synaptic cleft. The hypothesis is known as the 'junctional mechanism', the 'two process mechanism', the 'junctional two process mechanism' and the 'synaptic theory of transmission'. According to the synaptic theory, nerve impulses are transmitted from one neuron to another as follows: nerve impulses arrive at the synapse at varying intensities. If they are sufficiently intense they trigger the release of specialized  molecules contained in small vesicles in the synaptic knob - 'neural transmitter molecules' or 'neurotransmitters'. The neurotransmitters are released through the synaptic membrane of the synaptic knob - the presynaptic membrane - and propagated across the synaptic cleft. When they reach post synaptic membrane of the neighbouring neuron they attach to protein receptor molecules i.e. 'binding sites'. The binding sites are specialized for the attraction and binding of neurotransmitter molecules. The binding of neurotransmitter molecules to the receptor molecule forms a 'transmitter-receptor complex'.

    The formation of the transmitter-receptor complex triggers a change in the membrane permeability of the connecting neuron.The nature of the transmitter-receptor complex alters the postsynaptic membrane in one of two ways:the effect is 'excitatory'... the effect is 'inhibitory'. The binding is excitatory if it lowers the threshold for initiating or 'firing' the signal and produces movement of electrically charged ions which results in the depolarization of the membrane and generation of a new nerve impulse...  'excitatory binding'.The binding is inhibitory... it raises the threshold for firing the signal and produces movement of electrically charged ions which results in the further polarization of the membrane and the failure to generate a new nerve impulse i.e. 'inhibitory binding'.

    Nerve impulses are transmitted across the synaptic clefts only if excitatory binding exceeds inhibitory binding. As a result of excitatory binding, existing synaptic connections are strengthened and new ones are created... leading to reinforcement of existing neural pathways and the creation of new ones... 'neuroplasticity'. The neuron discharges impulses only when the synaptic excitation is much stronger than inhibition. The resulting 'synapse modification' or 'neuroplasticity' is the basis for learning.

 Each neuron has a threshold for transmission across the synapse... Each neuron has a critical threshold for generating a new impulse in a connecting neuron.

The 'engram' refers to the physical changes in the brain that accompany learning. Search for the engram is the search for evidence that experience produces permanent changes in the nervous system,

 An impulse is transmitted only if it is sufficiently intense and its strength exceeds a critical point when the interior of the cell becomes positive with respect to the exterior i.e. 'critical threshold' The threshold is the minimum number of electrochemical pulses per second required to trigger a response and generate or 'fire' a new signal.  Each neuron has a critical threshold for transmission across the synapse... generating a new impulse in a connecting neuron.  The transmission of impulses from one neuron to the next depends on the number of electrochemical pulses reaching the synapse. If this number exceeds the critical threshold required for triggering a response in the connecting neuron, then the signal is fired. An impulse is transmitted from one neuron to the next if there are enough pulses to trigger a response and 'fire' the signal.  Nerve impulses as electrical signals are first converted to chemical messages before they are transmitted across the synaptic clefts. There is a new working hypothesis which provides an explanation for the problem of information flow across the gaps which separate the neurons. The hypothesis is known as the 'junctional mechanism', the 'two process mechanism', the 'junctional two process mechanism' and the 'synaptic theory of transmission'. According to the 'synaptic theory', the transmission of nerve impulses from one neuron to another occurs as a result of the interplay of two separate processes -'synaptic excitation'  and 'synaptic inhibition'. Synaptic inhibition and synaptic excitation are instrumental in the formation of nerve circuits and networks or 'neural pathways' which are functional in learning and the 'retention of learning' or 'memory'.  The transformation of neural information and its storage as memory involve only nerve cells and their interconnections.

Information flow in the brain depends on the strength of incoming stimuli. These must be strong enough to produce nerve impulses of sufficient intensity to ensure their transmission across the synaptic clefts and their propagation along connecting neurons. This is of particular significance to learning theory. 

('brain-based learning'). 

 The synapse and the transmission of nerve impules via neurotransmitters... synaptic function: interaction or 'binding' between neurotransmitter molecules and protein receptors

Anatomy or structure of the synapse The synapse is a structure which is specialised for the function of transmitting nerve impulses across connecting neurons... for the transmission of impulses from one neuron to the next. Its structure can be described in terms of three main components: first, the  specialized point of contact... connection on the presynaptic or  the limiting membrane of the terminating axon 'terminal button' of the axon terminal -the 'synaptic knob' 'synaptic button,'derived from the multiple axon branches resulting from the bifurcation of the axon at many points along its length; second, specialized point of contact... the point of connection on the  membrane of the postsynaptic neuron... 'postsynaptic membrane' 'or subsynaptic  membrane  of a  dendrite of the connecting neuron; third, the gap between the two points of contact the 'synaptic gap' or  'synaptic cleft' . The gap separates the two communicating neurons by a millionth of an inch... two one thousandths of a millimeter (0.000002mm) or twenty nanometers. John Carew

The synapse plays a critical role in information flow which is the basis for learning Nerve impulse do not jump from one neuron to the next.  At the synapse, nerve impulses are converted to chemical processes which excite or inhibit activity in the connecting neuron depending on their strength (intensity) which determines the molecular events at the synapse (synaptic activity). Depending on the occurrence of excitation or inhibition synapses are either strengthened or weakened. New synapses can be created. Established synapses can deteriorate. As a result of this process of 'synapse modification' neural pathways are altered. Alteration of neural pathways involves the physiological process of continuity of information from one part of the brain to another i.e. 'information flow'. Information flow is a function of the propagation of nerve impulses along the neurons and their transmission from one neuron to another across the gaps which separate them, the 'synaptic clefts'. The effectiveness of synapses to initiate or 'fire' the propagation of new signals on connecting neurons involving a series of complex molecular events and depends on nerve impulses which are strong enough to increase the strength or 'potency' of other synapses so that  their influence enhances the creation of new synapses and new pathways. When stimuli are not strong enough then synapses regress. Formation of new synapses depends on stimulation through activity. Changes in neural pathways and the creation of new ones constitute the biological basis for 'learning' and the retention of learning or 'memory'. Synapse modification is the 'trace of learning' or 'memory trace' or 'engram'.

 The discovery of the synaptic cleft modified the picture of the brain as a 'syncitium' of neurons and raised a major problem in brain biology. If each of the millions of single neurons in the brain has a separate biological existence then how are nerve impulses transmitted from one neuron to a connecting neuron if there is a gap which separates them? In other words what mechanism provides for the continuity of information in the brain i.e. 'information flow'? The answer is in the functioning of the synapse.

The function of the synaptic cleft is explained in a working hypothesis known as the 'synaptic theory of transmission of impulses' which provides an explanation for the problem of information flow from one neuron to the next when there are gaps which separate them.

 Generation and propagation of nerve impulses: molecular events at the synapse ... synaptic theory of transmission of impulses as a 'working hypothesis'. synaptic transmission involves a series of complex molecular events.

Nerve impulses  are propagated to the synapse in the form of packets of electrochemical pulses or 'signals'. They arrive at the synapse in bursts of a few at a time  toa thousand per second. If the signals are sufficiently intense they are transmitted to connecting neurons and propagated along their axons.

A nerve impulse as an electrochemical pulse triggers the influx of calcium ions into the dendrites. The calcium combines with the protein 'calmodulin' to form the calciumcalmodulin complex which has a powerful metabolic action resulting in the manufacture of 'macromolecules' such as proteins which are instrumental in increasing the potency of the synapses and in increasing their numbers. ... Not all are transmitted across the synaptic cleft.

 Each neuron has a a critical point or critical threshold for firing an incoming nerve impulse and generating a new impulse in the connecting neuron. If the threshold is lowered by the impulse crossing the synapse then the effect is 'excitatory'. If the threshold is raised then the effect is 'inhibitory'. Activity in the postsynaptic membrane is either inhibited or excited, correspondingly preventing or enhancing the propagation of new impulses along the connecting neuron.

 The generation and propagation of a new impulse depends on the specific properties of the nerve impulses - the intensity of the signal and therefore on the strength of the stimulus... determines whether or not a nerve impulse excites or inhibits activity in the connecting neuron and whether a new signal is fired. An impulse is transmitted only if it is sufficiently intense and its strength exceeds the critical threshold required to generate or 'fire' a new signal and its continued propagation along the axon of the connecting neuron.. when the synapse is excited above the threshold. The threshold is the minimum number of electrochemical pulses per second required to trigger a response. The stronger the stimulus, the more intense the impulse and the greater the likelihood it will be transmitted across the synaptic cleft. If the stimulus is not intense enough, connections are not made and transmission does not occur.

SYNAPTIC TRANSMISSION: SYNAPTIC THEORY EVENTS AT THE SYNAPTIC JUNCTION: SYNAPTIC ACTION Nerve impulses in the form of electrochemical pulses do not jump from one neuron to the next. They are first changed into chemical messages. The arrival of electrochemical pulses at the synapse triggers the release of specialized neural transmitter molecules, known as 'neurotransmitters.' These are synthesized in the pre-synaptic cell and stored in small vesicles located in the synaptic knob. When the appropriate electric signal arrives, they are released through the presynaptic membrane and propagated across the synaptic cleft. They attach to special receptor binding sites on the postsynaptic membrane. Their binding triggers a change in the membrane permeability of the connecting neuron. Receptor molecules are proteins in the cell membrane of the connecting neuron. They attract and bind the neurotransmitter molecules which are released across the synaptic cleft. The resulting transmitter-receptor complex alters the postsynaptic membrane in one of two ways: it has an 'excitatory' effect or an 'inhibitory' effect, depending on its effect on the small pores which allow passage of ions across the membrane. Opening of the pores makes the membrane more permeable to the ions anmd results in the depolarization of the membrane. The cell is more easily excited. The binding of neurotransmitter molecules to receptor molecules on the postsynaptic membrane excites the cell if it enhances the movement of electrically charged ions across the membrane. In this way the binding is 'excitatory' if it results in the depolarization of the membrane. A new action potential is generated in the connecting neuron. In this way the nerve impulse is transmitted from one neuron to a connecting neuron. Closing of the pores makes the membrane less permeable to the ions and results in further polarization of the membrane. The cell is less easily excited. The binding of neurotransmitter molecules to receptor molecules on the postsynaptic membrane inhibits the cell if it prevents the movement of electrically charged ions across the membrane. In this way the binding is 'inhibitory' if it results in the further polarization of the membrane. The generation of a new action potential is inhibited and the nerve impulse is not transmitted to the connecting neuron. SYNAPSE The transmission of nerve impulses from one neuron to another  up to a thousand per second. SYNAPSE-PHYSICAL "TRACE' OF LEARNING

"Learning occurs as a result of changing the effectiveness of synapses ... At the synaptic junction between neurons, signals pass from the synaptic knob of one neuron and are propagated across the synaptic cleft to the neigboring neuron. Signals are transmitted to the synapse in the form of electrochemical pulses. When they reach the synaptic knob, it emits neurotransmitter molecules. These are propagated across the synaptic cleft. Depending on the nature of the synapse, they initiate or inhibit the 'firing' of new signals along the axon of the neighboring neuron. Signals reach the synapse as bursts of electrochemical pulses. They are collected from other neurons through the dendrites. They enter the cell body for processing and are sent outwards through the axon. They enter the cell body for processing and are sent outwards through the axon which bifurcates at many points giving rise to numerous 'axon terminals.' Bifurcating at many points, the axon gives rise to numerous 'axon terminals.' At the synaptic junction between neurons, signals pass from the synaptic knob of one neuron and are propagated across the synaptic cleft to the contact point on the connecting neuron. The signal crosses the synaptic cleft (about one millionth of an inch wide) Signals arrive at the synapse -so many per second in the form of bursts of electrical pulses. They are converted into a given number of chemical packets. If this number exceeds the critical threshold required for triggering a response in the neighboring neuron, then the signal is fired and the the electrical code is changed into the chemical code for transmission along the axon of the neighboring neuron Incoming signals are collected from other neurons through dendrites. At the synaptic junction between neurons, signals pass from the synaptic knob of one neuron and are propagated across the synaptic cleft to the contact point on the connecting neuron. Signals reach the synapse as bursts of electrochemical pulses - so many per second. These do not jump from one neuron to the next. The electrical code of transmission is first changed into the chemical code of transmission. The arrival of electrochemical pulses at the synapse triggers the release of specialized neural transmitter molecules, known as 'neurotransmitters.' These are contained in small vesicles located in the synaptic knob. They are released through the presynaptic membrane and are propagated across the synaptic cleft. They attach to special receptor binding sites on the postsynaptic membrane. Their binding triggers a change in the membrane permeability of the connecting neuron. The binding is excitatory if it causes the movement of electrically charged ions and results in the depolarization of the membrane. A new action potential is generated and the nerve impulse is transmitted. The binding is inhibitory if it results in the further polarization of the membrane. The generation of a new action potential is inhibited and the nerve impulse is not transmitted.

 SYNAPTIC TRANSMISSION: IMPULSES ARE TRANSMITTED FROM ONE NEURON TO ANOTHER WHEN THE SYNAPSE IS EXCITED ABOVE THE THRESHOLD LEVEL "Each neuron has hundreds or even thousands of synapses on its surface and it discharges impulses only when the synaptic excitation is much stronger than inhibition." (Popper K. and John Eccles. The Self and Its Brain. New York, London: Springer International, 1979 232) How does the presynaptic impulse evoke depolarization of the postsynaptic membrane? The nerve impulse causes transmitter molecules to be released from the synaptic vesicles...

A signal crossing the synapse can have one of two effects: it can have an excitatory effect by lowering the threshold for firing the signal; it can have an inhibitory effect by raising the threshold for firing the signal. Nerve impulses which reach the synapse are subjected to one of two synaptic processes: synaptic excitation or synaptic inhibition... (File ORGAN p. 8) Depending on the process occurring at the synapse, an incoming signal is transmitted to the connecting neuron and fired or not fired. Each neuron has a particular threshold for firing an incoming signal. The transmission of impulses from one neuron to the next depends on the number of electrochemical pulses reaching the synapse. If this number exceeds the critical threshold required for triggering a response in the connecting neuron, then the signal is fired. An impulse is transmitted from one neuron to the next if there are enough pulses to trigger a response and 'fire' the signal. A signal crossing the synapse can have one of two effects: it can have an excitatory effect by lowering the threshold for firing the signal; it can have an inhibitory effect by raising the threshold for firing the signal. The stronger the stimulus, the more pulses are generated. Depending on the number of pulses generated, they initiate or inhibit the 'firing' of new signals along the connecting neuron. Depending on the specific properties of the signal, its electrical effects either inhibit or excite activity in the connecting neuron. The continued transmission of the signal can be either inhibited or enhanced. If the inhibitory input exceeds the excitatory input then a connection is not made between one neuron and the next. If the excitatory input exceeds the inhibitory input then a connection is made between one neuron and the next. The two processes, synaptic inhibition and synaptic excitation are instrumental in the formation of nerve circuits and networks in the brain. The functioning of the brain involves this 'two process mechanism' as well as the mechanism of transmission of nerve impulses along nerve cells. Called the 'junctional mechanism' or 'two process mechanism', synaptic inhibition and synaptic excitation involves both neurons and their junctions. "..the synaptic excitation of all nerve cells evokes a depolarization of the postsynaptic membrane (the EPSP) which generates an impulse if it is sufficiently intense." The impulse of the presynaptic neuron must be sufficiently intense (above a certain threshold) in order to evoke a depolarization of the postsynaptic membrane which will generate an impulse in the postsynaptic neuron. (John Carew Eccles 1957. "The Physiology of Nerve Cells" Johns Hopkins Press Baltimore page 94) "..inhibitory action on a nerve cell is brought about by a depression of the EPSP below the threhold level for initiation of an impulse." (ibid. page 132)

1. Impulses or 'signals' in their electric form are first converted to their chemical form: 'neurotransmitters' When nerve impulses arrive at the synapse they are first converted from electrical messages or 'signals' into corresponding chemical messages in the following way. The arrrival of nerve impulses at the synapse triggers the release of specialized molecules which are manufactured, packaged and stored in small vesicles located in the synaptic knob of the pre-synaptic neuron i.e. 'neural transmitter molecules' or 'neurotransmitters'. The neurotransmitters are released through the presynaptic membrane of the synaptic knob and transmitted across the synaptic cleft. When they reach the postsynaptic membrane of the connecting neuron they attach to specialized protein receptor molecules or 'receptor binding sites'. Receptor molecules are proteins in the cell membrane of the connecting neuron. They attract and bind the neurotransmitter molecules which are released across the synaptic cleft. The resulting transmitter-receptor complex alters the postsynaptic membrane in one of two ways: it has an 'excitatory' effect or an 'inhibitory' effect, depending on its effect on the small pores which allow passage of ions across the membrane. The binding sites are specialized for the attraction and binding of neurotransmitter molecules. The binding of neurotransmitter molecules to the receptor molecule forms a 'transmitter-receptor complex'. The formation of the transmitter-receptor complex triggers a change in the membrane permeability of the connecting neuron. Depending on the nature of the complex and how it affects the permeability of the postsynaptic membrane the effect of the transmitter-receptor complex can be excitatory or inhibitory

 Opening of the pores makes the membrane more permeable to the ions and results in the depolarization of the membrane. The cell is more easily excited. The binding of neurotransmitter molecules to receptor molecules on the postsynaptic membrane excites the cell if it enhances the movement of electrically charged ions across the membrane. In this way the binding is 'excitatory' if it results in the depolarization of the membrane. A new action potential is generated in the connecting neuron. In this way the nerve impulse is transmitted from one neuron to a connecting neuron. Closing of the pores makes the membrane less permeable to the ions and results in further polarization of the membrane. The cell is less easily excited.

3. Synapse excitation  Membrane permeability is increased if the pores are opened allowing for passage of electrically charged ions and decreasing polarization (or increasing depolarization) thus lowering the threshold and exciting the neuron to generate a new signal. Binding which results in the depolarization of the membrane and the generation of a new impulse is  'excitatory binding'. Membrane permeability is decreased if the pores are closed preventing the passage of electrically charged ions and increasing polarization (or decreasing depolarization) thus raising the threshold and inhibiting the neuron from generating a new signal. The effect of the binding is an excitatory one if it lowers the threshold required for generating a new signal. If the nerve impulse reaching the synapse is sufficiently intense...  above the threshold required for depolarizing the postsynaptic membrane, then the effect of the binding is excitatory. The formation of the neurotransmitter-receptor complex opens the pores in the postsynaptic membrane so that it is made permeable to the passage of electrically charged ions resulting in decreased, polarization bringing it closer to the threshold required for generating the movement of electrically charged ions across the membrane ('action potential') which initiates a new impulse. In the destabilized, or 'excited state', a new nerve impulse is generated and the signal is propagated along the connecting neuron.

Dans une synapse excitatrice les sites récepteurs du neurotransmetteur sont situés sur les canaux au sodium de la membrane postsynaptique. Ainsi, l'interaction du neurotransmetteur avec son récepteur provoque une ouverture des canaux aux sodium entraînant une augmentation de la perméabilité aux ions sodium. 

L'entrée des ions sodium à l'intérieur du neurone postsynaptique conduit alors à une dépolarisation de la membrane postsynaptique. Le ppse ne dure que quelques millisecondes.

Si cette dépolarisation atteint le seuil d'excitation du neurone, un influx nerveux partira le long du neurone postsynaptique.On appelle potentiel postsynaptique excitateur (ppse) cette dépolarisation qui résulte de l'action du neurotransmetteur sur la membrane postsynaptique. 

 

 

4. Synapse inhibition  The effect of the binding is inhibitory if it raises the threshold required for generating a new signal. If the nerve impulse reaching the synapse is not sufficiently intense... below the threshold required for depolarizing the postsynaptic membrane, then the effect of the binding is inhibitory. The formation of the neurotransmitter-receptor complex closes the pores in the postsynaptic membrane so that it is made less permeable to the passage of electrically charged ions across the postsynaptic membrane resulting in increased polarization making it further stabilized near its resting value and further from the threshold required for generating the movement of electrically charged ions across the membrane which initiates a new impulse. In this stabilized or 'non-excited' state the generation of a new nerve impulse or action potential is prevented and the nerve impulse is not propagated along the connecting neuron. Binding which results in the further polarization of the membrane and does not generate a new impulse is 'inhibitory binding'.  Binding is inhibitory if it results in the further polarization of the membrane and does not generate a new impulse.

In inhibitory synapse the receptor sites of the neurotransmitter are situated on the potassium channels so that the  interaction between neurotransmitter with its receptor provokes increase in permeability to potassium ions. As the exterior of the postsynaptic neuron is positive, the efflux of potassium ions results in even higher increase of positive charge on the exterior and decrease of positive charge in the interior. The neuron is said to be hyperpolarised and the threshold for transmission is made higher. making it more difficult to stimulate

 5.  Continued transmission of impulses depends on the effect of binding. When they reach the postsynaptic membrane of the connecting neuron, the neurotransmitter molecules interact with specific protein receptor molecules known as  'transmitter receptors' or 'receptors'. Receptors are protein molecules specialized for the function of attracting and binding the neurotransmitter molecules. The receptor protein molecules are embedded in the semi-fluid matrix of the cell membrane with pieces sticking out above and below the surface. Many receptors have two functional components... the first is a  region on the surface of the receptor protein specialized  for the binding of the transmitter molecule i.e. 'receptor binding site' which is precisely tailored to match the shape and configuration of the so that the latter fits into the  transmitter molecule as specifically as a lock and key.The second is a 'selectively permeable pore' which is permeable to some ions and not to others. Binding between transmitter and receptor creates a 'transmitter-receptor complex' which triggers a change in the three-dimensional shape of the receptor protein and opens the pore component. This allows for the passage of ions inside and outside the cell membrane across their concentration gradients. Depending on the nature of the ions which move and the direction of their movement, the transmitter-receptor binding initiates a sequence of events which either inhibit or enhance the generation and propagation of new signals along the axon of the connecting neuron.  

 Binding of neurotransmitter molecules to the  receptor sites of receptor molecules can have either an excitatory effect or an inhibitory effect depending on the nature of the complex and how it affects the permeability of the membrane i.e. on the nature of the ions which move and the direction of their movement. The continued transmission of the nerve impulse depends on the effect of binding on the pores which allow for movement of ions across the membrane... how activity at the synapse affects the permeability of the membrane and hence the small pores which allow passage of electrically charged ions through the membrane...  Binding is inhibitory if it increases polarisation. The binding of neurotransmitter molecules to receptor molecules on the postsynaptic membrane is inhibitory if it closes the pores. Closing of the pores makes the membrane less permeable and prevents the passage of electrically charged ions.across the membrane This result is increased polarisation of the membrane. If the membrane is further polarized, it becomes stabilized near its resting value. This raises the threshold for the the generation of a new impulse and inhibits the continued transmission of the impulse to the connecting neuron. Binding is excitatory if it decreases polarisation. The binding of neurotransmitter molecules to receptor molecules on the postsynaptic membrane is excitatory if it opens the pores. Opening of the pores makes the membrane more permeable to the passage of electrically charged ions. This results in increased depolarization of the membrane. It is further destabilized and closer to the threshold for generating a new impulse and a new nerve impulse is initiated in the connecting neuron. 

If the inhibitory input exceeds the excitatory input then a connection is not made between one neuron and the next. If the excitatory input exceeds the inhibitory input then a connection is made between one neuron and the next. Propagation along the connecting cell occurs only if excitation of the synapse exceeds inhibition. Whether inhibitory or excitatory, binding of neurotransmitter molecules to their protein receptor sites is precisely controlled... control of transmission is maintained by a mechanism which rapidly inactivates the transmitter molecule once it is bound to its receptor molecule. If excitatory binding exceeds inhibitory binding then existing synaptic connections are strengthened and new ones are created leading to creation and reinforcement of new neural pathways. Each neuron discharges impulses only when the total synaptic excitation is much stronger than total inhibition. Electrical impulses from one axon are transmitted to the dendrites of connecting neurons if the excitatory input is greater than the inhibitory input. If the inhibitory input exceeds the excitatory input then a connection is not made between one neuron and the next. Connections are made between neurons only if the total synaptic excitation exceeds the total synaptic inhibition.Propagation along the connecting cell occurs ONLY if excitation of the synapse exceeds inhibition.

    The transmission of impulses from one neuron to the next depends on the specific properties of the 'presynaptic impulse' - the number of electrochemical pulses reaching the synapse (the stronger the stimulus, the more pulses are generated) as well as its effect on the 'postsynaptic membrane' (whether polarization is increased or decreased).

 Experiential learning and the synapse... Learning from experience -  'experiential learning' - stimulates the growth of new synapses... new synaptic connections. 

 Experiential learning is 'integrated learning' or 'holistic learning'. Holistic learning  the basis for learning from experience involves capacity for remembering memory cognitive faculty... the ability to store mental representations of experience important because it forms  ...required for adaptation and survival. The  allows for guidance of behavior on the basis of learning from experience...  Memory as the ability to remember and reflect on experience accounts for the human capacity for 'contemplation' or 'inner dialogue'  the basis for human dignity or 'freedom'. Education for freedom is based on recognition and respect for stages of human growth and development - 'sociocognitive stages'.

"The brain naturally learns and remembers the moment-to-moment events that constitute life experience. In order to make sense of new experience, the brain attempts to categorize and pattern new information with the information which is already stored in memory. The brain's mechanism of 'patterning' allows for the rapid processing of complex stimuli. At a very high rate of speed, the brain processes new experiential information in the context of previous patterns. Creating spatial maps and patterns, the brain naturally thrives on complexity. In its attempt to process new information from complex sensory input, the brain automatically recalls previously stored programs and formulates new programs. It formulates 'programs' which provide it with crucial information about the surroundings. Allowing for the instant memory of experiences, new information is rapidly processed in the 'spatial memory system' located in the brain's hippocampus. Necessary for survival, the spatial memory system drives the brain's innate search for meaning and is constantly monitoring and comparing the present with past surroundings and experiences. Learning and memory are most effective when facts and skills are 'embedded' in the natural spatial memory and in the context of real life experiences. New learning experiences are naturally 'embedded' in previous learning experiences. With continued learning and experience, the spatial memory system is enriched over time". (Renate Nummela Caine and Geoffrey Caine The Brain: Making Connections Alexandria, Va.: ASCD, 1991, 40-

 "Learning occurs as a result of changing the effectiveness of synapses so that their influence on other neurons also changes... Learning is a function of the effectiveness of synapses to propagate signals and initiate new signals along connecting neurons. Learning and experience change the structure of the neural networks." (Geoffrey Hinton, "How Neural Networks Learn from Experience," Scientific American, 267:3, September 1992, 145.)

 Learning is a function of transmission of signals along nerve cells or  'neurons' and across their interconnections or 'synapses'. All neurons transmit information in the form of electrochemical reactions which travel along their axons i.e. electrochemical pulses or 'nerve impulses'. Nerve impulses are 'electrochemical pulses,' regions of charge reversal travelling along the nerve fiber, also known as nerve 'signals'... 'action potential'... The structural unit of psychology.  

Experiential learning involves stimuli which are strong enough to establish new synaptic connections between neurons in the cortex Nerve impulses are transmitted to the connecting neuron and propagated along its axon only if they are sufficiently intense. The intensity of the impulse in the presynaptic neuron must be above the required threshold to depolarize the postsynaptic membrane. If the number of incoming electrochemical pulses exceeds the critical threshold, then the incoming impulse is transmitted and propagated along the connecting neuron. Learning is a function of stimuli strong enough to influence the effectiveness of synapses in the transmission of signals from one neuron to another across the synaptic clefts. Intrinsically motivated learning produces stronger stimuli than extrinsically motivated learning...   

 Learning is a natural function of the 'brain' ...based on brain functioning... 'brain functions'.  'Brain based learning' or 'natural learning' is  based on the optimal functioning of the brain i.e. 'optimal learning' or 'optimalearning'Optimalearning is natural learning which is compatible with brain functioning. So-called 'brain-compatible' methods of teaching facilitate the learning process. Facilitative teaching or 'thematic teaching' engages the learner's intrinsic motives for learning or 'human needs'. Motivation by human needs involves the psychological value of creativity and productivity or 'work' i.e 'intrinsic motivation'.

 Knowledge of the role of stimulation on synapse modification is directly related to educational methodology.The effectiveness of synapses is modified or altered by experience. In experiences of learning the stimulation of nerve impulses at the synapse enhances the influence of neurons on each other and causes new synapses to form and grow... 'experiential learning'. Experiential learning as 'successful learning' is a function of synaptic activity which involves stimuli strong enough to establish new synaptic connections between the neurons in the cortex of the brain....  'neuroplasticity'. When new synaptic connections are established then changes are brought about in the structure of existing nerve networks and nerve circuits and learning results.

 The biology of learning is based on the molecular events involved in the propagation of nerve impulses along neurons and their transmission across the points of connection i.e. 'synapses'. The synapse plays a critical role in the transmission of impulses from one neuron to the next. There are hundreds and even thousands of synapses on the surface of each neuron.

Learning methods based on the natural funtioning of the brain enhance learning because they enhance the formation of synaptic connections between nerve cells.   It is a function of the effectiveness of synapses to propagate signals and initiate or 'fire' new signals along neighboring neurons.

Those teaching and learning methods which inhibit learning inhibit the formation of connections between nerve cells, the 'synapses'.

 Learning is a physiological function of the brain involving the transmission of signals along nerve cells - neurons - and across their junctional connections - synapses. Learning involves the modification of the synapse.

 "Learning occurs as a result of changing the effectiveness of synapses so that their influence on other neurons also changes." (Geoffrey Hinton, How Neural Networks Learn from Experience, Scientific American, 267:3, September 1992, 145.)

"It is generally conjectured that the physical evidence for learning and memory is in the increase in potent synaptic connections. New synapses grow and develop. The modifiable synapses are the 'spine synapses' on the dendrites of neurons in the cerebral cortex and the hippocampus. Modifications are manifest in the growth and ramification of new synapses and in the hypertrophy of existing synapses. Regression of synapses occurs with forgetting. There is evidence for this function-dependent formation of synapses in the cortex" (John Eccles).

 "We are led to conjecture that the structural basis of memory lies in the enduring modifications of synapses, the functional connections between nerve cells. These would involve microstructural changes such as the 'hypertrophy' (increase in size) when memory is stored and regression of synapses in forgetting. The efficacy of synapses could be increased with conditioned activation or 'potentiation.' (John Carew Eccles 1957. "The Physiology of Nerve Cells" Johns Hopkins Press Baltimore 209-211)

Learning is a function of synaptic activity.

 Learning is a function of stimuli strong enough to influence the effectivity of synapses in the transmission of signals from one neuron to another acoss the synaptic clefts. Learning is a function of the effectivity of synapses to propagate signals and initiate or 'fire' new signals along neighboring neurons. Learning is a function of the point of connection between two neurons.  Learning is a function of modification of synapse ...the creation of new neural pathways or network

 Learning involves the formation and growth of functional nerve circuits and networks ... a function of physiological activity at the connections between nerve cells or 'neurons' i.e. the 'synapses'.

The biology of learning involves the molecular events associated with the propagation of nerve impulses along the neurons and their interconnections, the 'synapses'. Of particular significance for learning theory, the continuity of information in the brain is a function of stimuli which are strong enough to produce nerve impulses of sufficient intensity to ensure their transmission across the synaptic clefts and their propagation along connecting neurons.

 Learning and memory are a function of the chemical and molecular mechanisms involving the nerve cells and the junctional units connecting them, the 'synapses.' Insights into these mechanisms constitute the beginnings of the merging between cognitive psychology and molecular biology. The findings of neuroscientists, neurobiologists and psychobiologists have significant implications for education. They indicate that effective learning results from the wholistic response of the whole brain to incoming stimuli. From the findings of brain research and the neurosciences, it becomes evident that intelligence and all the other properties of the 'mind' result from the patterns of neurons and their connections. It becomes evident that the brain has a natural capacity to make connections and to process information as a functioning whole. The findings of brain research lend validity to a rational basis for wholistic education. They provide a rationale for the implementation of an integrative teaching and learning model. They provide a rational basis for pedagogical methodologies which will promote natural brain-based learning for natural knowledge. They provide the foundation for meaningful education through which students will be able to make connections between different areas of knowledge. Based on a knowledge of brain functioning, a reconceptualization of teaching and learning can result in a more effective educational experience for children growing up in the complex world of the 'global village

 

The molecular events at the synapse and synapse modification - the strengthening of existing synapses and the creation of new ones - becomes the focal point of investigation into the process of continuity of information flow in the physiological process of 'learning'. Learning is a natural function of modification and creation of neural pathways. Facilitation of natural learning - 'brain based learning' - by way of brain compatible methods of teaching - 'thematic teaching' is conducive to the brain's optimal functioning i.e.'optimalearning'. Optimalearning involves the psychological value of the individual's capacity for creativity and productivity or 'work'. Education which involves meaningful work engages t or 'self-actualisation'. Education for self-actualisation of the human potential for self-fulfillment... 'holistic education'.

 

Molecular activity at the synapse constitutes the physical evidence for learning and memory... engram. Today the widely accepted view among neurobiologists concerns the molecular events occurring at the synapse which represent the physical trace of learning or 'engram'. Learning is a physiological function of the brain involving the propagation of 'electrochemical signals' or 'nerve impulses' along neurons, and the initiation or 'firing' of new impulses along neighboring neurons as a result of their transmission across the gaps which separate them - the 'synaptic clefts' or 'synaptic connections'.  Learning and memory result from the formation of nerve circuits and networks through the increase of connections between neurons. When stimuli are strong enough to influence the effectiveness of synapses to influence other neurons... when they causes changes in the synapses that facilitate the formation of connections between neurons, then the processes of learning and memory become more efficient.. 'synaptic facilitation'. 

The biological basis of learning involves changes in the structure of neural pathways or 'networks' resulting from synapse modification or 'neuroplasticity'.  

 Learning as a function of changes in the structure of.. creation of...   neural pathways... neural networks  resulting from 'synapse modification' or 'neuroplasticity' The focal point for the biological basis of learning is the contact point between nerve cells or 'neurons' i.e. the 'synapse'. With experiences of learning, new synapses grow and develop to create neural networks.

...of the generation of nerve impulses at the synapse, their propagation at definite rates along the axons of neurons and their transmission across the synaptic clefts to neighbouring neurons. 

Optimalearning is a function of the creation and enhancement of synaptic transmission ...facilitated by teaching to the brain's potential for holistic learning with the use of teaching methods which are compatible with brain functioning or 'brain-compatible' i.e. 'facilitative teaching'. Facilitative teaching engages the learner's intrinsic motives for learning or 'human needs' i.e. 'intrinsic motivation'. Intrinsic motivation enhances learning... involves the psychological value of the human capacity for creativity and productivity or 'work'. Meaningful work engages the human potential for self-fulfilment... self-development ... development of 'moral consciousness' or 'conscience' i.e.  'mature growth' or 'self-actualisation'. Education for self-actualisation is 'holistic education'. In the holistic paradigm the teacher's role is 'facilitator of learning'. . Optimalearning is a function of natural 'brain functions'.

Neural tissue has the ability to change... 'neuroplasticity'   The capacity of neural tissue for long lasting modification at the synapses is known as 'neural plastic capability', 'neural plasticity' or 'neuroplasticity'. New synapses grow and develop through 'synaptogenesis' a physiological process which accounts for the 20-fold increase in the number of synapses - to more than 1,000 trillion - in the first months of life. (The number of possible synaptic connections is greater than the number of atoms in the universe.) The growth and development of new synapses produces changes in the structure of functional neural pathways and the creation of new ones. Neuroplasticity - the structural basis for the function of learning and retention of learning or 'memory' - includes microstructural changes in established synapses or 'synaptic connections' ... 'spine synapses' on the dendrites of neurons in the cerebral cortex and the hippocampus..., enlargement or 'hypertrophy' and ramification of existing synapses. Learning and memory are functions of natural physiological processes of 'brain functioning'. Formation of synapses in the cortex is 'function-dependent'. Evidence is provided in the comparison studies of rats raised in 'rich environments' and 'poor environments' (Marion Diamond). Diamond's studies indicate that experiential learning is a function of stimuli which are intense ...strong enough to produce nerve impulses of sufficient intensity to ensure their transmission across the synaptic clefts and their propagation along connecting neurons.   

Brain Plasticity: the physical structure of the brain changes as the result of experience. The brain maintains its plasticity throughout life. Although each brain is similarly constructed, with the same sets of systems for the senses and emotions, each brain is unique as a result of individual responses to new experiences.

Evidence for changes in neural tissue has been made available only in the past two decades. Evidence for function-dependent modification of synapses in the cortex. Marion Diamond studied the brains of rats raised in different environments. There were differences between those raised in cages equipped with facilities for play - complex or 'enriched environment' - and those kept in pairs or in isolation - 'impoverished environment'. Comparisons were made between three groups of littermates. Rats in the first group...the 'control group' were raised in standard laboratory cages - a few rats living in a cage of adequate size with food and water always present; rats of the second group were raised in an enriched environment - several rats living in a large cage furnished with a variety of objects providing stimulation for learning... every day a new set of play things drawn out a pool of 25 objects was placed in the cage; rats of the third group were raised in an impoverished environment... each rat living alone in a cage without any stimulation for learning. Studies were done to determine changes in the synapses of that region of the brain which showed increased brain weight with experience in enriched environments -the 'occipital cortex'. It was discovered that most synaptic connections occurred on the branches or 'dendrites' of the receiving neuron cell or on small projections of the dendrites - the 'dendritic spines'. A comparison of numbers of dendritic spines were made in brain sections of rats living in enriched and impoverished environments by Albert Globus of the University of California at Irvine. Globus compared the numbers of dendritic spines in the 'cortical neurons' or 'pyramidal cells'. He discovered an increase in dendritic spines of 'basal dendrites' when rats were raised in enriched environments. Other investigators also showed increased synaptic contact in the enriched environment group... up to 20% increase in the number of spine synapses and enlargement of the synaptic contact zones... also decreased synaptic contact for te impoverished environment group of rats deprived of stimulation.

Recent studies have shown that experience produces permanent modification of the functional connections between neurons in the brain - the 'synapses'. Modification of synapses or 'neuroplasticity' results in changes in the structure of neural circuits or 'neural networks' or 'neuronal systems' which can store information about the association of stimuli i.e. 'associative learning'. Neuroplasticity represents the structural basis of the engram. Learning involves the growth and  ramification of new synapses - 'synaptogenesis' - as well as the modifications of synapses involving   microstructural changes such as increase in size or 'hypertrophy' of existing synapses with the storage of knowledge or 'memory' (as the 'capacity to remember' or 'remembering') and 'the regression of synapses' with the loss of knowledge (as the loss of the capacity to remember or 'forgetting'). The modifiable synapses are the 'spine synapses' on the dendrites...'dendritic spines'... of neurons in the 'hippocampus' of the cerebral cortex.

See experiments with rats grown in 'enriched' versus 'impoversihed' environments. (Bennet, E.L., M.C. Diamond, D. Krech and M.R. Rozenzweig. 1964. "Chemical and Anatomical Plasticity of the Brain." Science 146: 610-619) Brains of rats grown in enriched environments increased in weight by 4%. There was an increase in enzymes for transmission of nerve impulses across synapses and increase in number of glial cells which provide nourishment to neurons.

The physical evidence for learning and memory is molecular activity at the 'synapse' and the increase in potent synaptic connections.

 Implications for education  The findings of brain research and the neurosciences... neuroscientists, neurobiologists and psychobiologists - the insights into the neural mechanisms of learning - have significant implications for education because they lead to new theories of learning. Learning is a natural function of the 'brain'. brain functioning... 'brain functions'.   As a functioning whole has a natural capacity to make connections and to process information. Thus effective learning results from the wholistic response of the whole brain to incoming stimuli... 'holistic perception'. The brain-based wholistic perception of reality forms the basis for adaptive behavior. Behavioural adaptation depends on an effective thinking process which involves the combined functioning of intellectual, affective and creative states of the mind. As the manifestation of the natural thinking function of the brain, the mind perceives reality - social and cultural reality - according to the individual's level of consciousness or awareness.

 Intelligence and all the other properties of the 'mind' result from the patterns of neurons and their connections - the neural pathways and networks. The teaching and learning methods which inhibit learning inhibit the formation of new connections or 'synapses' i.e. 'synaptic connections'. Methods based on the natural funtioning of the brain enhance learning because they enhance the formation of new synaptic connections.

The continuity of information in the brain is a function of stimuli which are intense ..strong enough to produce nerve impulses of sufficient intensity to ensure their transmission across the synaptic clefts and their propagation along connecting neurons. This is of particular significance to learning theory.

'Brain based learning' or 'natural learning' based on the optimal functioning of the brain optimal brain functioningi.e. 'optimal learning' or 'optimalearning'. Optimalearning  a function of natural 'brain functions' is natural learning which is compatible with brain functioning.  is a function of the generation of nerve impulses at the synapse, their propagation at definite rates along the axons of neurons and their transmission across the synaptic clefts...  a function of the creation and enhancement of synaptic transmission ...

So-called 'brain-compatible' methods of teaching facilitate the learning process by teaching to the brain's potential for holistic learning with the use of teaching methods which are compatible with brain functioning or 'brain-compatible' i.e. 'facilitative teaching'.  Facilitative teaching or 'thematic teaching' engages the learner's intrinsic motives for learning or 'human needs'.  Intrinsic motivation enhances learning by involves the psychological value of the human capacity for creativity and productivity or 'work'. Meaningful work engages the human potential for self-development ... self-fulfilment ...  development of 'moral consciousness' or 'conscience' i.e. mature growth' or 'self-actualisation'. Education for self-actualisation is 'holistic education'.i.e. 'or 'self-actualisation'. Education for self-actualisation is 'holistic education'. In the holistic paradigm the teacher's role is 'facilitator of learning'.

 Learning involves emotions...  Emotions cannot be separated from cognition...  emotions are crucial to the process of remembering or 'memory'.                                                                          

Human adaptability depends on education which encourages development of social intelligence. The formulation of effective teaching methods depends on the understanding of the global nature of brain functioning and of the connectedness or 'embeddedness' of 'knowledge' within previously assimilated experience. So-called 'experiential learning' engages the brain's natural holistic functioning which allows for optimal learning or 'optimalearning'. Optimalearning involves structural shifts in the basic premises of thought, feeling and behaviour. The shifts in 'consciousness' permanently alter the individual's point of view or 'perspective'. Such 'transformative learning' takes place when the emphasis is placed on learner interest and the 'process' of learning i.e. 'personalised learning'... involving learning emotions... motivation by intrinsic motives for behaviour... human needs i.e. intrinsic motivation... curiosity, awe, wonder of motivation by metaneeds or 'metamotivation'. "The brain does not separate emotions from cognition, either anatomically or perceptually". (Renate Nummela Caine and Geoffrey Caine. Making Connections: Teaching and the Human Brain)

Brain-antagonistic methods of teaching ('teaching for 'rote learning') and 'conditioned learning' actually inhibit experiential or 'real learning' because they inhibit the formation of new synaptic connections in the cortex of the brain. Methods based on the natural funtioning of the brain enhance learning because they enhance the formation of synaptic connections between nerve cells.

Using the method of personalized learning, teacher and learner are co-creators of the 'content' of learning while emphasis is on the 'process'. The teacher's function is to faclitate learning and their role is defined as 'facilitator of learning'. 'holistic education'

Intensity of stimuli is increased with 'optimalearning'...

As a natural physiological function of the brain the process of learning is enhanced by physiological factors such as nutrition, sleep, exercise... i.e. 'health' as 'wholeness' or 'wellness'.

 Stimulation from interest or 'curiosity' ...'intrinsic motivation' based on intrinsic motives for learning which are rooted in the instinct for self-preservation i.e. 'human needs. This is of particular significance to learning theory. Curiosity is naturally stimulated by challenge and complexity and elicits motivation which is intrinsic to the organism i.e. 'intrinsic motivation'.The physiological basis for global activation is the interactivity of the two cerebral hemispheres. Pedagogies based on the stimulation of intrinsic motivation are compatible with the natural functioning of the brain or 'brain-compatible'. In the design of curricula, courses areorganized around unifying or 'global themes'.  This learning methodology is confluent with the brain's natural capacity for the simultaneousperception of parts and wholes or 'holistic perception' The activation of the brain's natural function of global learning is the basis for brain-based learning or 'optimal learning'. Optimal learning or 'optimamearning' is successful learning because it results from the natural functioning of the brain. Learning is brain-based... 'brain functions' are the basis of learning. 'Brain based learning' or 'natural learning' is a function of the generation of nerve impulses at the synapse, their propagation at definite rates along the axons of neurons and their transmission across the synaptic clefts... optimal brain functioning or 'optimal learning' or 'optimalearning'. Optimalearning is a function of the creation and enhancement of synaptic transmission ...facilitated by teaching to the brain's potential for holistic learning with the use of teaching methods which are compatible with brain functioning or 'brain-compatible'... Teaching methods which stimulate... enhance the formation of synaptic connections also enhance learning... 'brain-based learning'. Methods which enhance the formation of synaptic connections are compatible with the natural functioning of the brain i.e. 'brain-compatible'. Brain compatible teaching methods enhance learning i.e. 'facilitative teaching'. Facilitative teaching engages the learner's intrinsic motives for learning or 'human needs' i.e. 'intrinsic motivation'. Intrinsic motivation enhances learning... involves the psychological value of the human capacity for creativity and productivity or 'work'. Meaningful work engages the human potential for self-development ... development of 'moral consciousness' or 'conscience' i.e. 'self-actualisation'. Education for self-actualisation is 'holistic education'. Holistic education increases the scope of so-called 'traditional education' as 'schooling'.

Natural learning for adaptation to changing social environment or 'adaptability' Recent findings in neuroscience indicate that in the 'process' of 'natural learning' the brain does not separate the emotions from cognition - neither anatomically nor perceptually.  They support those learning theories which are based on the natural functioning of the brain as the 'organ of learning'. The brain's natural function is to search for meaning in experience - to 'make meaning' of complex environmental stimuli or 'learn'. The learning function of the brain is as natural as the breathing function of the lungs. Learning is a natural function driven by the organism's instinctive need to search for meaning in the complexty of its environment. Human survival depends on learning which is effective because it produces creative or 'adaptive' behaviour i.e. 'adaptability'. Human adaptability depends on a natural process of learning which is meaningful to the individual i.e. 'meaningful learning'. Meaningful learning involves the brain's automatic response as a whole to the complexity of environmental stimuli. The brain's natural 'holistic perception' is based on the interconnectivity between the various parts of the brain resulting in the interconnectedness between the whole and its parts. The result is an interpenetrating or 'holographic' perspective in which each part is related to the whole so that it represents more than the sum of its parts giving rise to 'emergent properties' such as 'consciousness' or 'conscience'.

The holistic response of the brain is a function of the interactivity of the two 'cerebral hemispheres'.

 Inhibition of natural or 'brain-based learning' can lead to thwarting of development and diversion of creative energies towards the destructiveness of human wickedness or 'evil'. 

Recent findings in brain research suggest that it is possible to understand the functioning of the brain once there is sufficient explanation for the specific functions of individual nerve cells in the generation and propagation of nerve impulses and their transmission across the synapses. Communication between one neuron and the next takes place in the form of transmission of nerve impulses at the synapse. At the synapse, activity from the axon is converted to electrical stimuli that inhibit or excite activity in the connecting neuron. An electrical impulse from one axon is transmitted to the dendrites of the next neuron if the excitatory input is greater than the inhibitory input. As a result of ...depending on... synaptic activity(transmission of nerve impulses)... molecular events at the synapse... existing synapses are modified - strengthened or weakened - ('synapse modification')  ...new synapses are created... leading to the formation of 'neural circuits'... 'neural pathways'... 'neural networks'... based on brain functioning... 'brain functions'. Synapse modification becomes the focal point of investigation into the physiological process of continuity of information or 'information flow' in 'learning'. Learning is a natural function of the 'brain'. 'Brain based learning' or 'natural learning' based on the optimal functioning of the brain i.e. 'optimal learning' or 'optimalearning'. Optimalearning is facilitated ('facilitative teaching') with the use of teaching methods which are compatible with brain functioning or 'brain-compatible' i.e. 'thematic teaching'. Thematic teaching engages the learner's intrinsic motives for learning or 'human needs' i.e. 'intrinsic motivation' . Intrinsic motivation involves the psychological value of the human capacity for creativity and productivity or 'work'. Meaningful work engages the human potential for self-fulfilment or 'self-actualisation'. Education for self-actualisation is 'holistic education

 

            

In the brain, a neuron collects signals from other neurons through structures called 'dendrites.' Spikes of electrical activity (nerve impulses) are sent through the thin strand called 'axon' which splits into thousands of branches. At the end of each branch is the 'synapse' the point of connection with dendrites of another neuron. At the synapse, activity from the axon is converted to electrical effects that inhibit or excite activity in the connecting neuron. An electrical impulse from one axon is transmitted to the dendrites of the next neuron if the excitatory input is greater than the inhibitory input.

The transformation of neural information and its storage as memory involve only nerve cells and their interconnections.

... the neural junction is involved in the transmission of nerve impulses from one neuron to another. The transmission of nerve impulses from one neuron to another occurs at the junction between neurons, the specialized contact points known as 'synapses.' (John Carew Eccles, The Physiology of Nerve Cells, Baltimore: Johns Hopkins Press 1957)

 Communication between one neuron and the next takes place in the form of an electrochemical reaction known as the 'nerve impulse'.

The natural function of the brain is to search for meaning in experience. The brain is a product of human evolution through natural selection. As a product of human evolution, the human brain is best understood as an organ of learning adapted for the survival of the species. The specialized brain functions have evolved as a result of their survival value for the human organism and the human species. Language created the selection pressure under which emerged the human brain and the consciousness of self. The specialized brain functions have evolved as a result of their survival value for the human organism and the human species.

process of learning which is based on the brain's natural function in the con

LEARNING AND MEMORY ARE A FUNCTION OF SYNAPTIC ACTIVITY OR 'SYNAPTIC MODIFICATION' Learning is a physiological process... a natural brain function associated with the search for meaning in the complexity of the social environment... Learning is a function of the brain which involves the transmission of signals along neurons and across the synapses.

Learning and memory are a function of synaptic activity. Through a process of  'synapse modification' learning and experience change the structure of the 'neural networks'. Learning occurs as a result of changing the effectiveness of synapses so that their influence on other neurons also changes. Learning is a function of stimuli strong enough to influence the effectiveness of synapses in the transmission of signals from one neuron to another across the synaptic clefts. It is a function of the effectiveness of synapses to propagate nerve impulses or signals and initiate or 'fire' new signals along neighboring neurons.

WHAT DO WE KNOW ABOUT LEARNING? Learning is the natural function... Complex environmental stimuli include those in the field of focused attention and  those which are peripheral to it. The brain processes environmental stimuli which are in the field of focused attention and at the same time it processes those stimuli which are peripheral to it. In processing information from the environment, the brain consciously focuses on specific stimuli and responds to it on the conscious level of awareness (according to its subconscious interpretation of peripheral stimuli). Many environmental stimuli are perceivd unconsciouly and are processed at the subconscious level of awareness. The brain responds to peripheral stimuli at the subconscious level of awareness. The brain's 'holistic perception' of reality is the basis for its  behaviour which is 'adaptive' or non-adaptive' depending on its interpretation and evaluation of the environment. Evaluation is correct or incorrect depending on the individual's level of devel

Learning is a physiological function of the brain involving the transmission of signals along nerve cells and across their junctional connections. The number of nerve cells in the brain is fixed at birth and no new nerve cells grow and develop. Learning and experience change the structure of the neural networks. The number of nerve cells in the brain is fixed at birth and no new nerve cells grow and develop. Learning is a function of stimuli strong enough to influence the effectiveness of synapses in the transmission of signals from one neuron to another across the synaptic clefts. It is a function of the effectiveness of synapses to propagate signals and initiate or 'fire' new signals along neighboring neurons

"It is in the junctional mechanism that long lasting modifications of brain tissues must take place. Although adult nerve cells do not divide, a mechanism of permanent modification of brain tissue does display many of the properties of the mechanism of differentiation of embryonic tissue. Experientially initiated guided growth of new nerve fibers does take place and alters the spatial pattern of junctional relationships among neurons. Long term memory therefore becomes more a function of junctional structure than of strictly neural (nerve impulse generating) processes."

Learning is a natural function of the brain. It involves the transmission of signals along nerve cells and in addition the two process mechanism of signal transmission across their junctional connections, the synapses. The networks of the brain are a function of the activity of nerve cells and their functional junctions, the synapses. No new nerve cells develop in the human brain after birth. Modification of brain tissue occurs in the synapses.

Nerve impulses which reach the synapse are subjected to one of two synaptic processes: synaptic excitation or synaptic inhibition...

 The basic activity of synapses comprises two processes which determine the outcome of nerve impulses reaching the synapse: synaptic excitation and synaptic inhibition. Depending on the process occurring at the synapse, an incoming signal is transmitted to the connecting neuron and fired or not fired. Each neuron has a particular threshold for firing an incoming signal. The transmission of impulses from one neuron to the next depends on the number of electrochemical pulses reaching the synapse. If this number exceeds the critical threshold required for triggering a response in the connecting neuron, then the signal is fired. An impulse is transmitted from one neuron to the next if there are enough pulses to trigger a response and 'fire' the signal. A signal crossing the synapse can have one of two effects: it can have an excitatory effect by lowering the threshold for firing the signal; it can have an inhibitory effect by raising the threshold for firing the signal. The stronger the stimulus, the more pulses are generated. Depending on the number of pulses generated, they initiate or inhibit the 'firing' of new signals along the connecting neuron. Depending on the specific properties of the signal, its electrical effects either inhibit or excite activity in the connecting neuron. The continued transmission of the signal can be either inhibited or enhanced. If the inhibitory input exceeds the excitatory input then a connection is not made between one neuron and the next. If the excitatory input exceeds the inhibitory input then a connection is made between one neuron and the next.

opment i.e. 'sociocognitive stage'.

 

 Research findings provide a rational basis for pedagogical methodologies which will promote natural brain-based learning for natural knowledge... they provide a rationale for the implementation of an integrative teaching and learning model. They provide the foundation for meaningful education through which learners can make connections between different areas of knowledge.

Today it is generally known that the physical basis of the mind is the brain.

As a whole, the thinking skills together constitute the most significant skill of all :'learning to learn'.

Overall, the findings of brain research lend validity to a rational basis for 'holistic education' - an education that is more appropriate for learning and living in the complexities of a fast-changing social environment of the 'global village'.

Scientific psychology as the universal human psychology:Freud's 'scientific psychology' was incomplete because there was insufficient knowledge of the mechanisms underlying the apparent 'continuity of information' in the brain.

Scientific psychology is based on scientific principles of biology and social sciences such as sociology, anthropology etc.

Outline of progress in psychobiology: Seahare 'Aphasia' - very primitive invertebrate with a few giant neurons which can be identified and studied individually. To find possible neuronal mechanisms of behavioural habituation a simple form of learning.

As processes of acquiring and retaining new knowledge, the mental functions of learning and memory are analysed in terms of mechanisms invloving the neurons and their connections.

Insights into the cellular and molecular mechanisms of  learning constitute the beginning of the bridge being formed between cognitive psychology and molecular biology.

It becomes possible to view the learning process in all its complexity.

 The aim of brain research is to describe the functioning of the mind and the learning process. The aim of brain research is the search for the neural basis of mental phenomena, which include urges, desires, subconscious forms of learning, emotions and affect as well as conscious thought, imagination and creativity. This framework is based on the study of biological substrates of mental functions. As processes of acquiring and retaining new knowledge, the mental functions of learning and memory are analysed in terms of mechanisms involving the neurons or nerve cells. Insights into the cellular and molecular mechanisms of learning constitute the beginnings of the bridge being formed between cognitive psychology and molecular biology. The findings of neuroscientists, neurobiolists and psychobiologists have significant implications for education. They indicate that effective learning results from the wholistic response of the whole brain to incoming stimuli. From brain research and the neurosciences we learn that the brain has a natural capacity to make connections. The findings of brain research lend validity to a rational basis for wholistic education. They provide a rationale for the implementation of an integrative teaching and learning model.

evolutionary psychology a matter of 'cognition'... focuses on evoled prperties of human nervous systems

 cognitive structure, like morphological structure has evolved through natural selection

Foundational assumption is that neural tissue is functionally organised in favor of survival and adaptability...

Mind-body problem Soul as mind or 'psyche'  .... Soul as separate from the body

 "One of the most powerful and influential images of the psyche is found in Plato's philosophy. In the Phaedrus the soul is pictured as a charioteer driving two horses, one representing the bodily passions and the other the higher emotions. This metaphor encapsulates the two approaches to consciousness - the biological and the spiritual - which have been pursued, without being reconciled, throughout Western philosophy and science. This conflict generated the 'mind-body problem' that is reflected in many schools of psychology, most notably in the conflict between the psychologies of Freud and Jung... (Capra The Turning Point p.166)

Ever since the beginnings of human civilization people have been interested in the workings of the mind or the 'soul' and how it relates to human behavior. Different parts of the body have been designated as the physical basis of the 'mind'. For the Assyrians and Sumerians it was the liver. For Aristotle and the Greeks, it was the heart. The early philosophers described the mind in terms of contemplation and discovery of the 'truth'. They investigated the nature of the 'mind' in discussion and debate over the classical philosophical questions such as "what is the nature of reality?" Classical philosophers recognized that inquiry was the mind's primary tool for the contemplation of philosophical questions. According to Socrates, it was possible to 'discover the truth' through inquiry, discussion and argument... Today it is generally known that the physical basis of the inquiring mind is the brain. Classical philosophical questions can be discussed in terms of the functioning of the brain. The process of acquiring knowledge, 'cognition', is analysed in the context of brain functions. The new field of psychobiology deals with the mind's attempts to understand itself. Combining psychology with brain biology, psychobiology is the study of the biological basis of the mind. In the new context of psychology, psychobiology asks the old question "what is reality?" As a function of the individual's level of consciousness, the concept of 'reality' is connected with psychology.

the 'action potential' the electrical impulse is the result of an electrochemical reaction which is a function of the special properties of the cell membrane. An electrochemical impulse involves the movement of electrically charged chemical ions - ionized atoms of chlorine, sodium and potassium.

permanent modification in neural tisssue. localization of the 'memory trace.' 1950 Lashley (Lashley K.S. "In Search of the Engram" Society for Experimental Biology, Great Britain, Physiological Mechanisms in Animal Behavior, New York: Academic , 1950 pp. 454-482 Karl Pribram, eminent psychologist, dealt with the issue suggested by Lashley in 1929: the search for the engram Karl H. PRIBRAM "Languages of the Brain: Experimental Paradoxes and Principles in Neuropsychology." Prentice-Hall, Inc. Englewood Cliffs, New Jersey 1971

as the 'action potential,' the electrical impulse is the result of an electrochemical reaction which is a function of the special properties of the cell membrane.

Nerve impulses are 'electrochemical pulses,' regions of charge reversal travelling along the nerve fiber, also known as nerve 'signals.' (Roger Penrose, The Emperor's New Mind: Concerning Computers      Minds and the Laws of Physics, (N.Y. Oxford Univ. Press,      1989), 375-392.) Their transmission is primarily involved with the movement of sodium ions into the interior of the cell

They are initiated by incoming physical or chemical stimuli which decrease the voltage gradient and depolarize the membrane. With the depolarization of the membrane, there is an increase which decrease the voltage gradient and depolarize the membrane. With the depolarization of the membrane, there is an increase in its permeability to sodium ions on the outside of the membrane. The sodium gates open and the positively charged sodium ions rush into the cytoplasm, further depolarizing the membrane. The neighboring sodium gates are opened resulting in increased permeability to sodium ions. They rush into the cell interior, depolarizing the membrane and increasing its permability to other sodium ions and so on in a sequential fashion throughout the length of the axon. The inrush of sodium ions into the interior of the cell from one point of the membrane to the next constitutes the nerve impulse. The electric charge on one impulse is about one tenth of one volt and each impulse lasts about one thousandth of a second. At a critical point calledthe 'threshold,' the inside of the cell becomes positive with respect to the outside. Sodium ions cease to move across the membrane and the differential voltage returns to the resting membrane potential value of -70 millivolts. In this fashion, nerve impulses or 'signals' are transmitted along nerve cells throughout the brain.

text of experience is experiential or meaningful learning

Known as 'brain-based learning' or 'wholistic' learning, meaningful learning is based on the optimal functioning of the brain as a whole. Brain-based learning is based on the natural learning functions... the natural 'thinking' functions of the brain.

 Brain-based wholistic learning involves those brain processes which are both conscious and unconscious.

 The unconscious aspect of learning is involved with the intrinsic motives for learning or 'intrinsic motivation'. It is possible to 'teach' for growth to full humanness with the replacement of deficiency motivation by growth motivation or 'metamotivation'. A natural by product of the experience of growth and freedom within the community in which effective learning is driven by the need for self-initiated personal development toward self-actualization is respect for others and for the environment. The recognition of the psychological value of work in human psychological development is the basis for the organization of schools for humanity. Children themselves can advise in the planning of environments which will help them to grow to psychological maturity living by the values which are the special attributes of the human social organism.

 

 EnHANCEMENT OF SYNAPTIC FUNCTION BY USAGE Discussion on use and disuse "Residual potentiation would be a special illustration of the enhancement of synaptic function by usage." "It can be envisaged that the normally occurring bursts of impulses in the presynaptic fibers bring about frequent minor distensions of the synaptic knobs, which are hence maintained at a normal level of size and effectiveness. With disuse...the absence of these repeated distensions results in a gradual shrinkage of synaptic knob size and hence leads to defectiveness of function....." "..direct experimental evidence has been obtained in support of the hypothesis that usage leads to increased functional efficiency of synapses and disuse to defective function." This is the 'plastic change' of neurons. (John Carew Eccles "The Neurophysiological Basis of Mind: The Principles of Neurophysiology" Oxford Clarendon Press 1952 Chapter VI "Prolonged Functional Changes (Plasticity) in the Nervous System" p. 193-227 Section C. Synaptic Activity and Plasticity p. 203-211p.)

Mediation of psychological states is through the synapse                        

   Learning from experience or 'experiential learning' involves memory as the 'process of remembering'... 'capacity to remember' In the cognitive paradigm memory represents a dynamic representation of the 'process of remembering' . 'memory' is a verb which represents a faculty of 'cognition'... the process of 'remembering' how an event is experienced. As a cognitive ability memory is a function of the indifvidual's level of personality development or 'sociocognitive stage'In the cognitive paradigm a memory is a record of how an event is experienced rather than a replica of the event itself. Memory is the cognitive process of remembering’ a past experience. Knowledge of the experience is somehow encoded in the form of neural patterns resulting from the strengthening of 'synaptic connections' between groups of 'nerve cells' or 'neurons'... the 'engram'. The engram is a representation of a memory or  'memory trace' in the form of some biochemical change that accompanies learning and the retention of learning. This is the 'neural network model' model of memory. Memory as the process of remembering is a unique pattern of neural activity reconstructed from the combination of a 'retrieval cue' and an 'engram'. The retrieval cue is information in the present environment which triggers the process and induces a pattern of activity which is similar to the  pattern which was previously encoded as the engram. The two are combined to form a new neural network. The resulting transient or enduring changes in the brain represent an expression of the way in which an experience is remembered or 'memory'. The memory is a  subjective perception of an event and incorporates the person's thoughts and feelings at the time of the original encoding. The same thoughts and feelings determine the cues which are required to elicit the process of remembering. Retrieval of... recall of 'a memory' depends on the availability of a set of cues which are closely related to the original encoding... depends on reinstatement of adequate 'encoding conditions'

Learning and memory are most effective when facts and skills are 'embedded' in the natural spatial memory and in the context of real life experiences. Example is the learning of native language. Learning of language occurs by way of internal mental process and social interaction. Social interaction is crucial to effective learning. The system is enriched aver time with learning and experience.  Learning and experience change the structure of the neural networks.

To illustrate the difference between accessing the taxon system and the locale system see fig 8.1page 94 and 8.2 page 96.(Caine) With the locale learning only one trial is needed to recognize the pattern and remember the information. With the taxon system, many trials are needed. To reduce the number of trials for remembering the information, one first has to find or create the pattern by connecting the new information with previously acquired knowedge of the tic-tac-toe diagram.

Recognition of the pattern involves both the intellect and the senses. Natural meaningful brain-based learning involves the conjunction of cognition and emotion. The learner is encouraged to participate actively in his/her own learning... find or create patterns by connecting new information with previousluy acquired knowledge..

 Notion of 'localisation of memory' or 'engram' ...history of the notion of physiological basis of memory. In the traditional paradigm 'memory' is a noun which represents knowledge stored at specific sites in the brain as the replica of an event... memory trace, memory engram' or 'engram' from German 'engramm' derived from Greek 'gramma' meaning 'something written'. The term was coined in 1908 by German biologist Richard Semon to denote the hypothetical change in neural tissue which corresponds to a memory... to denote the permanent trace left in the brain by a remembered stimulus... permanent physical trace of learning... postulated to account for the persistence of memory as remembered mental stimulus... the conscious recollection or 'memory' of an episode of experience... 'episodic memory'. Ever since medieval times the problem of the 'localisation of memory' has been based on the assumption that there is a one-to-one correspondence between bits of stored information and episodic memories. Numerous attempts have been made to localise the evidence that experience produces permanent modifications in neural tisssue i.e. 'search for the engram'. For most of its history, psychology has been concerned with the study of memory as if it were a static object which could be defined in terms of knowledge that is stored and somehow physically implemented in the brain. Psychologist Gordon Bower (1967) defined the engram in terms of a bundle of features describing an event. 

For centuries scientists have been striving to answer the question: where is the engram and how does it function? The model of memory as a static object is no longer considered to be an adequate explanation for the structural basis of memory. In the cognitive paradigm memory represents a dynamic representation of the 'process of remembering'. 

Modern neuroscience and the study of memory... .. The idea that memories are stored at specific sites in the brain is an old one. Since medieval times, scientists have tried to localize the physical traces of learning and memory, the 'memory trace'. The mental function of memory was assigned to a specific region of the brain until the middle of the 20th century and  the search for the engram has inspired brain research or 'neuroscience' since its beginnings in the eigteenth century with the research and theories of German-French physiologist and anatomist Joseph Gall.

 Joseph Gall (1758-1828). Gall was interested in brain functions and made the first comparative study of brain anatomy. Gall made the first anatomical and comparative studies of animal brains and proposed that different psychological functions were located in distinct organs of the brain.. He carried out research in what he called 'cranioscopy' - later known as 'phrenology'

     Pierre Paul Broca (1824-1880) known for his work on the localisation of brain functions specifically the language function... the 'speech area' or 'Broca's area' in the posterior frontal lobe of the left cerebral hemisphere.

  Russian physiologist Ivan Pavlov used dogs as subjects in his studies on classical conditioning. Pavlov demonstrated that the dogs could be conditioned to salivate at the sound of a bell as a result of associating  the bell ringing with food. In other words the pairing of a conditioned stimulus (food) that normally elicits a conditioned response (salivation) with an unconditioned stimulus (bell ringing) resulted in the association of the unconditioned stimulus (bell ringing) with the conditioned response (salivation)... learning of conditioned responses or conditioned learning... 'conditioned reflex'. The formation and storage of conditioned reflexes ('implicit memory') did not occur after removal of the cerebral cortex.

    American psychologist William James demonstrated the existence of two types of memory... conscious primary memory or 'short-term memory' which lasts a matter of seconds... successive events that result in a continuous experience... secondary memory or long-term memory... permanent memory which is held indefinitely in the unconscious and can be raised to the conscious level or 'consciousness'.

Karl Lashley (UPI/Corbis-Bettman)  Karl Lashley and his search for the neural basis of memory or 'search for the engram'. Lashley did not believe in the notion of the engram as localised memory. He believed that learning was a distributed process that could not be isolated within any particular area of the brain... Behavioural scientist and pioneering neuroscientist ... one of the most prominent neuropsychological researchers of his day... Karl Lashley was a student of John Watson (1878-1958) founder of 'behavioural psychology' or 'behaviourism'... Lashley collaborated with Watson on the first classical conditioning studies done in the US. He spent his whole career in an intensive search to localize memory traces. He trained animals to perform specific tasks and lesioned specific areas of the cortex either before or after training and then recorded the effects of the lesions on the animal's ability to remember what they had learned. Lashley summarized 33 years of research and failed efforts to discover the localisation of memory and popularised the term 'engram' in his influential paper 'In Search of the Engram' published in 1950. As a result of his work, he concluded that memories are distributed throughout certain functional areas of the cortex... Furthermore he believed that it was futile to search for a neural basis for memory since behavioural psychology would eventually be reduced to physiology.  His two general principles were as folllows: According to the Equipotentiality Principle memories are not localized but are instead are distributed within functional areas of the cortex ... all cortical areas can be substituted for one another as far as learning is concerned; According to the Mass Action Principle the reduction in learning is proportional to the amount of tissue destroyed, the location of the lesion is not important... increase in disruptive lesions led to reduction in  complex learning. Lashley proposed that learning is an activity of the brain as a whole and that memories are stored in the entire brain rather than at specific sites - an issue which was taken up by American psychologist Karl Pribram.  Despite the controversial nature of his two principles they have contributed nevertheless  to the field of neural network or 'connectionist' research. Lesioning experiments suggest that network processing is distributed and nonlocalized and gives rise to properties of emergence... 'emergent properties'. Lashley's proposal removed the possibility of localizing memory. In 1949 this view was challenged by  Lashley's student, psychologist Donald Hebb. Hebb proposed that associative learning involved a simple cellular mechanism. 

  Donald Hebb continued the 'search for the engram' and inspired research in the development of a new field - the biology of learning or 'psychobiology'. Associative learning and Hebb's learning rule... He presented the most successful theoretical view of the mechanism of learning in his 'Theory of Cell Assemblies' in which he proposed that the sites of memory storage were to be found in assemblies of nerve cells and their connections supporting the view that changes occuring during learning develop among interconnections of neurons throughout wide areas of the brain rather than at one particular area in the brain... reintroducing the idea that it was possible to find the underlying mechanism of learning and memory. His hypothesis known as 'Hebb's learning rule' was also known as the 'pre-post coincidence mechanism'... also the 'pre-post associative mechanism' because it claimed that "coincident activity in both cells involved is critical for strengthening the connections (associations) between the pre-synaptic and post-synaptic neurons...when an axon cell A ...excites cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficacy, as one of two cells firing B, is increased." Particular kinds of learning have been proven to involve the development of particular circuits of neurons. "Hebb reintroduced the idea that it was possible to find the underlying mechanism of learning. He inspired research in the biology of learning, and the development of a new field - psychobiology. Hebb's work resulted in a continuation of the 'search for the engram.'" (Eric Kandel and Robert Hawkins, "The Biological Basis of Learning and Individuality", Scientific American, 267: 3, Sept 1992, 80.)  

Ladislav Tauc and Eric Kandel... 'conditioning reflex' as simple associative learning (associating two events)... In l963 Tauc and Kendel proposed a second mechanism for associative learning or  'associative learning rule'. While working with the marine snail Aplysia at the Institute Marey in Paris, they found that the synaptic connection between two neurons could be strengthened without activity of the postsynaptic cell when a third 'modulatory neuron', enhances release of neuro- transmitters from the terminals of the presynaptic neuron. They suggested a mechanism of associative learning, the 'pre-modulatory mechanism', which involved coincident electrical impulses in the pre-synaptic neuron and the modulatory neuron. This is the mechanism of the 'classical conditioning reflex' the simplest type of learning as association of  two events.

 In the 1950s John Sperry using 'split-brain technique' based on the separation of 'cerebral hemispheres...  studied epileptic patients who underwent surgical removal of the 'hippocampus' and neighboring regions in the 'temporal lobe' of the brain. He discovered that the operation impaired the kind of memory which requires conscious participation i.e. 'explicit memory' thus assigning the function of memory to a specific location in the brain.

"An underlying assumption of early studies of memory systems was that the mediation of both explicit and implicit memory involves complex neural circuits". ( Eric R. Kandel and Robert D. Hawkins 'The Biological Basis of Learning and Individuality' Scientific American September 1992 79-86) Neurobiologists are still asking whether each neuronal system is governed by the same or different sets of learning mechanisms or 'rules'.

 "We are led to conjecture that the structural basis of memory lies in the enduring modifications of synapses, the functional connections between nerve cells. These would involve microstructural changes such as the 'hypertrophy' (increase in size) when memory is stored and regression of synapses in forgetting. The efficacy of synapses could be increased with conditioned activation or 'potentiation.' (John Carew Eccles 1957. "The Physiology of Nerve Cells" Johns Hopkins Press Baltimore 209-211)

"Intelligence and all the other properties of the 'mind' result from the patterns of interconnections and interactions between the nerve cells". (Geoffrey E. Hinton "How Neural Networks Learn from Experience." Scientific American September 1992 145-151)       

Memory as the process of remembering involves the interaction of conscious or 'explicit' memory and unconscious or 'implicit' memory. The two distinct forms or 'systems' of learning and memory as the process of remembering: non-declarative and reflexive or 'implicit' memory is unconscious remembering; declarative and 'explicit' memory is conscious remembering.

Short term memory as natural memory system is necessary for survival because it drives the search for meaning of events of life... (as opposed to forced memory or 'rote memorization' associated with compulsory learning or 'schooling'.) which take place in space... hence the 'spatial memory system' also known as 'locale memory system' allows for the instant memory of experience. The spatial memory system relies on the hippocampus in the limbic system,New information is processed in  in the context of previous patterns of learning which are embedded in previous learning experience. Spatial maps are created and tested to provide   information about the environment... is monitored and compared with past experience.   'Explicit memory' is memory of conscious learning i.e. 'declarative learning' or 'explicit learning'. Explicit learning is fast. Only one trial is required and that involves the association of simultaneous stimuli permitting the storage of information about a single event. Explicit memory is a function of structures in the 'temporal lobe' of the brain. In contrast 'implicit memory' is memory of unconscious learning i.e. 'non-declarative learning' or 'implicit learning'. Implicit learning does not require conscious participation. Implicit learning is slow. It requires many trials which involve the association of sequential stimuli permitting the storage of information about predictive relations betweeen different events. Implicit memory is expressed through activation of the sensory and motor neuronal systems engaged by the learning task. Implicit learning or 'reflexive learning' can be observed in various 'reflex systems' of both vertebrates and invertebrates.

 The cellular systems for both - the neuronal systems - can store information about the association of stimuli (associative learning and memory)

 

   Quotation references:

"One of the most important lessons to derive from brain research is that in a very important sense, all learning is experiential. What we learn depends on the global experience, not just on the manner of presentation. We do not automatically learn enough from our experience. What matters is how experience is used. ...in deliberately teaching for the expansion of natural knowledge, we need both to help students have appropriate experiences and to help them capitalize on the experiences." (Renate Nummela Caine and Geoffrey Caine. Making Connections: Teaching and the Human Brain. 104)

"As a result of research in the neurosciences, new understandings of the functioning of the brain are being applied to new techniques teaching for so-called 'brain-based learning.' Research in the neurosciences challenges some strongly held beliefs.   brain research challenges "the belief that teaching can be separated into the cognitive, affective, and psychomotor domains... the notion that learning must take place through rote memorization... the idea of "teaching to behavioural objectives (as it) ignores other functions of the brain and other aspects of memory and learning." (Renate and Geoffrey Caine Making Connections)    

("...the synaptic excitation of all nerve cells evokes a depolarization of the postsynaptic membrane which generates an impulse if it is sufficiently intense... A new action potential is generated and the nerve impulse is transmitted". (John Eccles)

"Recent findings in brain research suggest that it is possible to understand the functioning of the brain once there is sufficient explanation for the specific functions of individual nerve cells and their connections. The resulting patterns of nerve impulses, neural circuits and networks form the basis of the brain's functions. The knowledge gained from findings in brain research forms the basis for theories of brain-based learning and can be applied to educational philosophies and pedagogies. The findings confirm the antagonism between 'traditional' teaching methods and the natural learning function of the brain. (Conner, James "Cutting Edge: Mind & Molecules" Journal of Developmental Education vol 16, number 3, Spring 1993: page 34)

"A reconceptualization of the teaching and learning process is being formed on the basis of the knowledge of brain functioning. Attention of educators is being shifted towards the biological basis of the human potential for learning and thinking. The science of the brain, neurobiology, and the science of the mind, cognitive psychology, have merged over the past several decades giving rise to the new field of 'psychobiology.' (Eric Kandel and Robert Hawkins, "The Biological Basis of Learning and Individuality", Scientific American, 267: 3 Sept 1992, 79.)

"The science of the brain, neurobiology, and the science of the mind, cognitive psychology, have merged over the past several decades giving rise to the new field of 'psychobiology.'' (Eric Kandel and Robert Hawkins, The Biological Basis of Learning and Individuality, Scientific American, 267: 3 Sept 1992, 79.)

References

 Eccles, John Carew and Robinson The Wonder of Being Human: Our Brain and Our Mind 

Eccles The Physiology of Nerve Cells. Baltimore, MD: Johns Hopkins Press 1957

Eccles, J.C. The Physiology of Synapses. Berlin: Springer Verlag, 1964

 Eccles, J.C. "The Neurophysiological Basis of Mind: The Principles of Neurophysiology Oxford: Clarendon Press 1952 Chapter VI Prolonged Functional Changes (Plasticity) in the Nervous System p. 193-227 Section C . Synaptic Activity and Plasticity p. 203-211p. 

 Eccles, J.C. The Understanding of the Brain

Gerald Fischbach  Mind and Brain Scientific American 276: 3, September

. Hinton, G. How Neural Networks Learn from Experience Scientific American, 267:3, September 1992, 145

  Popper K. and Eccles J.C. The Self and Its Brain. New York, London: Springer International, 1979 8. Ornstein R. and R.Thompson The Amazing Brain

Thomas Leahey and Richard Harris, Human Learning. New Jersey: Prentice Hall, 1989 

Eric Kandel and Robert Hawkins, The Biological Basis of Learning and Individuality Scientific American, 267: 3, Sept 1992 79-86)

Eric Kandel, "Nerve Cells and Behavior", Scientific American 223: 1 July 1970, 281.   

 Karl Pribram (ed.)  On the Biology of Learning

 J. Allan Hobson, The Dreaming Brain London: Penguin Books  

  Penrose, Roger. The Emperor's New Mind: Concerning Computers Minds and the Laws of Physics N.Y. Oxford University. Press, 198.

 websites: College of Micronesia FSM (Federated States of Micronesia) www.comfsm.fm/socscie/biolearn.htm