How the Human Brain Developed and How the Human Mind Works

by Manfred Davidmann

SUMMARY

As a result of the work reported here there has emerged a much clearer appreciation of what happens during the course of a night's sleep, and clear explanations of the role of dreaming and the meaning of dreams.

The report explores the functioning and role of the two halves of the human brain and the relationship between them. It is the right half which usually communicates with the primitive parts of the human brain and this is related to the functioning of the autonomic nervous system and the immune system.

The report also relates the functioning of the brain to behaviour, showing to some extent how human behaviour is affected by the primitive instincts of our reptilian ancestors.

CONTENTS

THE BRAIN

How the Human Brain Evolved

Reptilian Brain
Mammalian Brain
Human Brain

Brain Waves
Brain Scanning

SLEEP AND SLEEPING

Body-Temperature and Sleep Rhythms
Sleeping
Deep Sleep and REM Sleep
Role of DEEP Sleep
Role of REM Sleep

DREAMING AND DREAMS

Content of Dreams
Role of Dreams

LEARNING, MEMORISING AND REMEMBERING (Receiving, Storing and Recalling)

Types of Memory

Procedural Memory
Declarative Memory

Associating Memories and their Components

Working Memory
External Memory

Stored Information (Perceived Content)
Learning (Memorising) and Understanding
Development of Brain Functions in Humans

Development of Brain Functioning in Foetus and Newborn
Role of REM Sleep in Infants
Changes in Sleep-wakefulness Rhythm during First Year of Infant's Life
Learning by Playing and by Experience
Change from Eidetic to Linear Memory

CONCLUSIONS - BRAIN, MIND AND BEHAVIOUR (Human Behaviour and how the Mind works)

Instincts and Instinctive Behaviour
Conscious Behaviour: Learning and Evaluating, Memory and Memorising
Communicating Non-verbally: Conveying Information by Using Images

Instinctive Behaviour
Subconscious Behaviour (Functioning)
Memorising

Adapting to the Environment: Changing Instinctive Behaviour
Adapting to the World in which we Live: Changing Behaviour Patterns
Evaluation and Understanding
The Struggle for a Better Life
Main Conclusions

NOTES AND REFERENCES

Notes   <..>
References   {..}

ILLUSTRATIONS (Click any illustration to see the full-size chart)

1. Sleep Pattern: Day-Night-Day
2. One Sleep Period (One Night)
3. The Human Brain

Relevant Current and Associated Works

Relevant Subject Index Pages and Site Overview

THE BRAIN

HOW THE HUMAN BRAIN EVOLVED

We slowly ascended from lower life forms to what we are today, by a process of natural selection from randomly occurring changes. Each change had to prove its worth by surviving the continual battle for existence, being against being, species against species and this process has gone on for many millions of years.

As far as we know the human brain evolved in three main stages {3}. Its ancient and primitive part is the innermost core reptilian brain. Next evolved the mammalian brain by adding new functions and new ways of controlling the body. Then evolved the third part of the brain, the neocortex, the grey matter, the bulk of the brain in two symmetrical hemispheres, separate but communicating. To a considerable extent it is our neocortex which enables us to behave like human beings.

So the human brain consists of these three different but interconnected brains and the way in which these three brains interact with each other underlies human behaviour. {3}

How the brain evolved and functions is explored and described in the immediately following chapters which cover how the brain evolved, sleep and sleeping, dreaming and dreams, and how we learn, memorise and remember.

The final chapters contain conclusions which describe how the functioning of the human brain and of the human mind determine behaviour.

What we see in this report raises a number of pertinent questions which need answering. Questions such as why do we have to struggle for a better life and what motivates human beings.

Reptilian Brain

Innermost in our brain is what is called the reptilian brain, its oldest and most primitive part. The reptilian brain appears to be largely unchanged by evolution and we share it with all other animals which have a backbone.

This reptilian brain controls body functions required for sustaining life such as breathing and body temperature. Reptiles are cold-blooded animals which are warmed by the daylight sun and conserve energy by restricting activities when it is dark. The biological clock (controller) for their activity-rest cycle is located in the eye itself {10}.

At this level of evolution, behaviour relating to survival of the species, such as sexual behaviour, is instinctive and responses are automatic. Territory is acquired by force and defended. Might is right.

Mammalian Brain

Next to evolve from the reptilian brain was the mammalian brain. An enormous change took place as mammals evolved from reptiles, the mammalian brain containing organs {11, 12}:

For the automatic control of body functions such as digestion, the fluid balance, body temperature and blood pressure (autonomic nervous system, hypothalamus).

For filing new experiences as they happen and so creating a store of experience-based memories (hippocampus).

For experience-based recognition of danger and for responding to this according to past experience. And for some conscious feelings about events (amygdala).

To this extent the mammal is more consciously aware of itself in relation to the environment. Millions of neural pathways connect the hippocampal and amygdala structures to the reptilian brain and behaviour is less rigidly controlled by instincts. It seems that feelings such as attachment, anger and fear have emerged with associated behavioural response patterns of care, fight or flight. {4}

Human Brain

And the mammalian brain became the human brain by adding the massive grey matter (neocortex) which envelopes most of the earlier brain and amounts to about 85 per cent of the human brain mass.

This massive addition consists mostly of two hemispheres which are covered by an outer layer and interconnected by a string of nerve fibres. {13}

The brain is actually divided into its 'hemispheres' by a prominent groove. At the base of this groove lies the thick bundle of nerve fibres which enable these two halves of the brain to communicate with each other.

But the left hemisphere usually controls movement and sensation in the right side of the body, while the right hemisphere similarly controls the left side of the body.

We saw that with the mammalian brain emerged feelings such as attachment, fear and anger and associated behavioural response patterns.

And human emotional responses depend on neuronal pathways which link the right hemisphere to the mammalian brain {4} which in turn is linked to the even older reptilian brain.

Fascinating is the way in which work is divided between the two halves of the brain, their different functions and the way in which they supplement and co-operate with each other.

Most people (about 80 per cent) are right-handed <4> and in the vast majority of right-handed people, the ability to organise speech and the ability to speak are predominantly localised in the left side of the brain. But the right side can understand written and spoken language to some extent at least. {14}

"Appreciating spatial perceptions depends more on the right hemisphere, although there is a left hemisphere contribution. This is especially true when handling objects" {14} and concerning abstract geometric shapes and music.

Roger Sperry, Michael Gazzaniga and their colleagues found that, when presented with a stimulus, both hemispheres were active and could recognise the nature of visual stimuli as well as spoken words.

But while the left hemisphere can express itself by verbally describing a stimulus, the right hemisphere can express itself non-verbally by selecting the matching stimulus.

The left hemisphere deals with word choice, rules of grammar, and the meaning of words. The right hemisphere apparently determines the emotional content of speech. {14}

So a general overview of the functional division of activities between the two hemispheres would be:

Left Hemisphere

Communicates by using words, has highly developed verbal abilities, is logical and systematic, concerned with matters as they are.

Right Hemisphere

Communicates using images (pictures), has highly developed spatial abilities, is intuitive and imaginative, concerned with emotions and feelings.

But the two hemispheres are interconnected and communicate, the human mind brings together these abilities and skills into a comprehensive whole whose operation depends on the way in which its parts contribute and co-operate with each other.

The right hemisphere links to the primitive older part of the brain, and I consider that it communicates using images with its primitive 'unconscious' functions. Thinking in pictures is fast. Think of how long it takes to describe a picture, a scene, in words and compare this with the speed of taking it in by looking at it. But images may be described, or transformed into a narrative, by the left hemisphere.

Language is both spoken as well as written, verbal and visual. And speech and language and associated pictures, images and memories appear to be located all over the brain. Cognition of meaning (knowing and understanding sentences, for example) is high level processing which includes both semantic and visual processing. And behaviour involves the integration of activities in many different parts of the brain.

So now the human brain includes the processing and memorising of images and of their components. And the development of language and corresponding mental processing connected with memory and memorising. As well as the development of a wide range of emotions, of feelings, of care and affection, and the capability for objective and logical thinking and evaluation. And the later development of written languages and artificial images.

BRAIN WAVES

The brain functions by sending electrical signals from one place to another. Very small charges pass between nerve cells, accompanied by changes in electrical potential, in voltage.

This activity can be measured and displayed as a wave form called brain wave or brain rhythm. The height of the wave is a measure of the potential difference, its frequency is a measure of the rate at which electrical charges pass through a nerve cell or nerve fibre. {1}

A person's brain is active all the time, waking and sleeping, producing and shifting between distinct wave forms which are commonly grouped as follows:

Table 1

Brain Waves

When delta waves predominate then one is said to be in a delta state.

People can think of relaxing and so strengthen alpha waves, or can do mental arithmetic and so weaken them. This enables people 'to perform an on-off decision, switching a light on or off or moving a cursor on a screen'. {5}

BRAIN SCANNING

Electroencephalograph (EEG) {1}

The EEG measures electrical activity of the brain using pairs of electrodes placed at different (internationally specified) points on the scalp. It is used by doctors for diagnosis and research.

It seemed that the EEG would provide the key to understanding how the brain functions, but it proved very difficult to interpret these brain waves, or to deduce from where in the brain they originated.

Magnetoencephalograph (MEG) {2, 7}

The MEG, however, can measure

the oscillating millisecond fluxes of the brain in real time. Furthermore, unlike the EEG, granted enough mathematical sophistication and computing power, you get a good idea of the location of the electromagnetic source in the brain.

And it can be used to

record magnetic and electrical fields within the brain simultaneously, tracking impulses moving (a distance of) a few millimetres at up to 200 miles per hour.

In real time, that is 'in perhaps 10 milliseconds'. And 'usually accurate to within one or two millimetres in pre-surgical mapping'.

And in this way enabling responses to be tracked within the brain.

SLEEP AND SLEEPING

BODY-TEMPERATURE AND SLEEP RHYTHMS

Day and night alternate over 24 hours due to the rotation of the planet, and the start and length of daylight varies with the seasons.

So internal biological clocks (controllers) evolved for controlling activities related to the environment such as those of cold-blooded animals which need to maintain their body temperature by warming themselves in the sun. Reptiles are cold-blooded animals warmed by the daylight sun and conserve energy by restricting activities when it is dark. And the biological clock which controls their activity-rest cycle is located within the eye. {10}

But about 180 million years ago, warm-blooded mammals evolved from their cold-blooded reptilian ancestors by developing the ability to maintain a constant body temperature by biological processes. This freed them from depending on daylight and the weather for survival. Deep sleep appeared at the same time. {4}

The earlier mammals were reproducing themselves by hatching their young out of eggs. But about 180 to 130 million years ago, many mammals evolved into giving birth directly from the womb, their young being born alive after having been developed for a considerable period within the womb. Their young have to grow and learn much for a long time before they can survive independently, for many years in the case of human beings. The human brain now has much greater learning capacity.

In mammals, information about light and darkness is transmitted from the eye to a biological clock, now situated in the mammalian brain, which controls the sleep-wakefulness rhythm. Another biological clock controls the body-temperature rhythm, and these biological clocks together control the related body-temperature and sleep-wakefulness rhythms. {10}

While the body's temperature is held at a constant level, it varies by about 0.5 deg C from a low at about 05.00 hours to a high at about 18.00 hours. It appears that we tend to go to sleep after our body temperature has began to fall and tend to wake up after it has started to rise.

"The length of the geophysical day is 24 hours. Our sleep-wakefulness rhythm (circadian rhythm) has a duration which varies from individual to individual (usually between 25 and 28 hours) but is always longer than 24 hours. And our biological rhythms are adjusted accordingly, day by day," by these internal biological clocks, to the external geophysical day, to the environment. People sleep, on average, between 6.5 and 8.5 hours. {10}

The body-temperature clock also controls the appearance of REM sleep.

SLEEPING

There are key mental states each characterised by its own brain wave pattern <5>. When awake we can be attending or concentrating, or we can be relaxed. When asleep we could be in SHALLOW sleep, DEEP sleep, or REM sleep.

Shallow sleep is often referred to as 'Stage 2' sleep, and Deep sleep as 'Stage 4' sleep.

During REM sleep (Rapid-Eye-Movement sleep), the eyes move rapidly and continuously. At times REM sleep is referred to as dreaming sleep and sometimes called paradoxical sleep, or called paradoxical sleep only when referring to animals.

During Deep sleep the body's muscles are relaxed, heart beat and breathing are slow and regular. In REM sleep the body's muscles are paralysed while heart beat and breathing fluctuate as they would during emotional upsets in waking life.

Brain-wave frequency of the different sleep stages we pass through in the course of a night are outlined in Figure 1 'Sleep Pattern: Day-Night-Day'. From being wide awake before going to sleep, we relax, sleep lightly (shallow) for ten to fifteen minutes before sleeping deeply. Following Deep sleep we REM sleep after which we wake up through relaxing to being fully awake. <6>

Figure 1 Sleep Pattern: Day - Night - Day

Back to Contents list

Deep sleep is followed by REM sleep. In order to achieve this as far as possible within a night, the brain arranges alternating periods of deep sleep followed by REM sleep <8>.

The illustration shows graphically what happens to the brain's electrical activity as the night progresses, illustrated by the frequency of the brain waves. As we progress from being awake through sleep to being awake again, the frequency drops, reaching its lowest point while in deep sleep and then rises again to the wide-awake level.

Amplitude, that is voltage, changes inversely. It increases when the frequency drops, reaching its highest level during deep sleep, and then decreases again to the wide-awake level.

Considering adults, that is excluding the young and the elderly, on the whole we 'Deep Sleep' during the first half of the night, and 'REM Sleep' during the second. But possibly because we cannot be certain how long we will sleep, whether our sleeping period will be interrupted unexpectedly, Deep sleep and REM sleep are divided into shorter sleep periods which alternate, something like:

Table 2

One Sleep Period (One complete night)

Figure 2 One Sleep Period (One Night)

Back to Contents list

That we Deep sleep first and that REM sleep follows Deep sleep is clearly shown in Figure 2. This shows how the two kinds of sleep alternate as Deep sleep ends and REM sleep begins and proceeds.

Deep Sleep and REM Sleep each take up about 20 to 25 percent of the night's sleep. The remainder is largely taken up by transition 'Shallow' sleep' periods which enable brain and body to adjust to the next type of sleep, and by occasional brief periods of intermediate 'Stage 1' and 'Stage 3' sleep <6>.

DEEP SLEEP AND REM SLEEP

We have already seen much about Deep sleep and about REM sleep so this seems a good point to include in this section also what has been said so far.

Both Deep sleep and REM sleep appeared about 180 million to 130 million years ago in mammals as they evolved from reptiles.

Deep sleep and REM sleep are the core sleep activities, each taking up about 20 to 25 percent of the night's sleep, the remainder being taken up by shallow transition sleep periods.

On the whole we Deep sleep during the first half of the night, and REM sleep during the second. Deep sleep and REM sleep are divided up into shorter sleep periods which alternate.

So now we can list the characteristics of Deep sleep and of REM sleep, as follows:

Deep Sleep

Deep sleep appeared at about the time warm blooded mammals evolved from their cold-blooded reptilian ancestors by developing the ability to maintain a constant body temperature by biological processes.

As we progress from being awake through sleeping to being awake again, the frequency of the brain waves drops, reaching its lowest point while in Deep sleep and then rises again to the wide-awake level. (See Figure 1 'Sleep Pattern: Day - Night - Day')

During Deep Sleep the body's muscles are relaxed and heart beat and breathing are slow and regular.

Deep sleep 'dream-like experiences are more like ordinary everyday thoughts and are usually rather banal and repetitive in content'. During Deep sleep 'one is not dreaming but thinking.' {4}

REM Sleep (Rapid-Eye-Movement sleep)

REM sleep also appeared at about the time warm blooded mammals evolved from their cold-blooded reptilian ancestors by developing the ability to maintain a constant level of body temperature by biological processes.

At this constant level there is a small but closely controlled body temperature rhythm (we tend to go to sleep after our body temperature has began to fall and tend to wake up after it has started to rise) and the body-temperature clock also controls the appearance of REM sleep.

On the whole we REM sleep during the second half of the night, after Deep sleep and before waking up through relaxing to being fully awake.

In REM sleep the body's muscles are paralysed while heart-beat and breathing fluctuate as they would during emotional upsets in waking life. Brain waves look like the waking pattern. The eyes move rapidly and continuously. <7>

Persistent rapid eye movement shows that dreaming is taking place and the brain paralyses the sleeper so that the dreams cannot be acted out.

Dreams tend to consist of "sensory illusions or hallucinated dramas" (imagined feelings or awarenesses), are not usually remembered unless the dreamer wakes up from the dream itself. "The length of time taken to dream of certain events is about the same as the time it would take to experience those events in waking reality." {4}

ROLE OF DEEP SLEEP

We saw that Deep sleep appeared about 180 million to 130 million years ago in mammals as they evolved from reptiles. And that during Deep sleep the body's muscles are relaxed and heart beat and breathing are slow and regular. In Deep sleep 'one is not dreaming but thinking'.

As reptiles evolved into mammals and mammals into human beings, complicated and interrelated physiological and biological changes took place. And it seems as if body maintenance and development takes place during Deep sleep.

For example, "during sleep, the endocrine organs come to life and secrete into the bloodstream hormones that affect the entire body" {10}.

ROLE OF REM SLEEP

"If REM sleep is prevented, it takes precedence over other kinds of sleep until the lack of REM sleep has been made good, at least to some extent. So human beings need REM sleep." {10}

Professor Lavie heads Haifa Technion's Sleep Laboratory. He reports {10} "that in some way or other, we can maintain contact with reality during REM sleep and even decide when to wake up with the help of internal signals", and that "REM sleep allows a smooth and rapid transition from sleep to wakefulness, and so can be viewed as a gate to wakefulness during sleep."

"Further findings at the Technion Sleep Laboratory demonstrated an additional advantage in awakening from REM sleep. When we examined how people functioned after awakening from REM sleep, we found that they performed very well at tasks which included orientation in space. These tasks, which are controlled by the right hemisphere of the brain, were performed with a lesser success rate after awakening from the Deep sleep of stages 3 and 4. In other words, a person awakening from REM sleep is immediately orientated in his surroundings, which is of cardinal importance to a smooth transition from sleep to wakefulness."

Which suggests to me that the left hemisphere is involved in Deep sleep 'dreaming' and the right hemisphere in REM sleep dreaming.

REM sleep appeared when, as we saw already, mammals evolved into giving birth directly from the womb, their young being born alive after having been developed for a considerable period within the womb. The young have to grow and learn much for a long time before they can survive independently, for many years in the case of human beings. Which applies particularly to the brain which now has much greater learning capacity.

During the first few days after birth the actual amount of REM sleep is very great and Lavie concluded that "it plays a vital role in the maturing stage of the nervous system" and that "it is possible that REM sleep is particularly important for procedural types of learning in which humans acquire motor and perceptual skills. Since during the first few months of life infants are busy acquiring new motor and perceptual skills, these findings may also explain the abundance of REM sleep at that particular time in our life".

Lavie also reports that REM sleep in cats "seems to be training their neural networks in mainly instinctive behaviour" and that "several studies have indicated a possibility that the consolidation of memory traces for at least certain types of learning occurs during REM sleep".

So the role of REM sleep appears to be that of generating dreams, of filing away memories for later use, and to enable us to wake up quickly and fully orientated.

DREAMING AND DREAMS

Dreaming, whatever this may be or whatever is taking place during REM sleeping periods, is likely to perform an essential function as otherwise the brain would not be paralysing the body to enable dreaming to take place.

Important also because it takes place regularly as a matter of routine and as all individuals are normally subject to this procedure.

In other words, there must be an important reason for sleeping in this way and for dreaming.

CONTENT OF DREAMS

The content of an individual's dreams normally corresponds with that individual's language and memories, beliefs and culture, depends on an individual's day-to-day life, experiences, preoccupations, likes and dislikes.

But at times dreams seem to originate from an unknown apparently internal source which has been given labels such as the 'unconscious' or the 'subconscious'. Occasionally dreams contain information beyond the experience, knowledge or understanding of the dreamer.

The dreams of the blind do not include sights or scenes but include noises, the sense of contact and emotional experiences. Lavie found that there were only single eye movements during their nonpictorial dream sleep. The longer they had been blind, the sparser the eye movements of blind people and so Lavie showed that grouped eye movements indicate dream pictures. {10}

Lavie records that early-REM-period dreams deal with the present, and in most cases lack story or central character. But "dream reports made in the early hours of the morning are richer in detail, central characters, and feelings, and, compared with dreams from the first half of the night, they tend to deal more with the dreamer's early childhood".

First dreams are not remembered in the morning but last dreams are, and it is these last dreams which the psychiatrist is most likely to hear.

Dreams may deal with what happened during the day which has just passed, or are about what took place more than a week ago, but do not as a rule deal with the events of the seven days or so which come in between. This gap seems to show that two kinds of memory are involved, a short-term working memory and a more permanent long-term memory, and that it may take a week or so before at least some of the information which reached the working memory is processed and stored in the long-term memory.

ROLE OF DREAMS

According to Jouvet "dreams arise from bursts of activity in biologically ancient parts of the brain, and both animals and humans get up and act out their dreams when the brain centres responsible for inhibiting movements during sleep are incapacitated". {4}

Theta rhythms have been observed not only in REM sleep periods in humans but also in animals when performing activities such as hunting on which survival depends.

"Instincts are an innate form of behaviour - in other words, patterns of motor behaviour which are not learned but stamped on the nervous system before birth. The behavioral patterns of numerous species which involve attack, defense, or copulation are instinctive, and the animal performs these actions from birth, without being trained to do so." {10}

According to Lavie, Jouvet hypothesised

"that one of the roles of paradoxical sleep was to train the neural networks which are related to instinctive behavior",

"that during paradoxical sleep these neural networks are activated independently of the muscles which are linked to the nerve cells and inhibited by the brain stem",

and that "because of the decisive importance of the instincts to the survival of the species, the neural networks linked to instincts are checked every night".

Dreams may "provide help in solving problems (or solutions to everyday problems), even scientific ones" and may "also be an inspiration for artistic creativity (for discovery and creativity)" and have also been the source of literary and musical inspiration.

There are many stories indicating that at least some dreams may be predicting events.

Dreams which predict events would be based on the situation as it exists just before the dream is dreamt, and the dream itself introduces another factor into the situation which has been predicted.

Bearing in mind the vast total number of dreams being dreamt every night by so many people world-wide, I also think that similarities or dream components which after the event has occurred are said to have predicted it or to refer to it, cannot at this time be credited with being more than coincidences.

Some people consider that dreams may be caused "by supernatural agencies such as gods or demons and are to be understood as messages. Dreams caused by gods are 'good' dreams sent to guide us; dreams caused by demons are 'bad' dreams sent to destroy us" and "people have tried to distinguish between 'good' and 'bad' dreams and to find rules for discovering what they mean." {4}

An inquiry commissioned by the Royal College of Psychiatrists <2> has concluded that any memory of severely traumatic events 'recovered through ... dream interpretation ... is almost certainly false'. Dream interpretations "usually reflect the training and personal convictions of the therapist". Beliefs that certain events took place are apparently being implanted and referred to as memories. {16}

LEARNING, MEMORISING AND REMEMBERING (Receiving, Storing and Recalling)

Human beings are learning all the time, storing information and then recalling it when it is required.

Massive volumes of information are being received continually. But only some of this information is selected and stored, and so becomes available for recalling later when required. Selection seems to be necessary as otherwise it may take far too long to recall any specific memory or possibly because we may not have sufficient capacity for storing everything in our brain.

But on the other hand we may not be able to recall a specific memory when we want to remember it, some stored information may have been forgotten.

TYPES OF MEMORY

Memory and memories have been defined or classified in different ways. Established is that there are two main types of memory, namely 'procedural memory' with information about how to proceed when doing something, and 'declarative memory' which contains what we know.

Both procedural and declarative memories are long-term memories and we also have a working (short-term) memory which enables the brain to evaluate the mass of incoming information and select what is to be retained and memorised and what is to be rejected.

Distinctions have been drawn also between different kinds of memory and memories, such as semantic (verbal), episodic (events as part of a sequence), eidetic (detailed mental images) and visual (images as seen). In addition to what we see, we also remember other sensory information such as sounds, smells, tastes and what we touch.

Procedural Memory

This memory stores information about how to proceed when doing something, stores information such as how to drive a car, play football or play an instrument.

This type of memory is long-lasting. The memories are actions, habits or skills which are learned by repetition and which can be changed by many repetitions, by training. {11, 14}

Declarative Memory

This is long-term memory and it contains all you have experienced or learned, all the information gained by you from childhood onwards.

No one really knows where this enormous database is located but it seems that each type of component memory is located in a kind of memory location of its own.

Associating Memories and their Components

Suppose we remember a person saying something. The component parts of this memory, components such as shape of face, sound of voice, colour of hair, are stored in different locations. They are associated with each other, cross-indexed if you like, so that a memory can be recalled from remembering just one of its components. Component memories are continually being associated with other old or new component memories, enormously increasing the range and flexibility of what can be recalled.

And so we may be able to recall a person's name by remembering the colour of his hair, or the shape of his face.

Working Memory

The working memory enables the brain to evaluate the mass of incoming information and select what is to be retained and memorised and what is to be rejected.

External Memory

In addition we have the vast mass of externally prepared and stored information which is accumulating. It has accumulated ever since people told stories to their young who in turn retold them to later generations and ever since writing was invented and the printed word accumulated, followed by pictures, photographs, films and videos, television and computerised manipulation of text and images. All of which spread and proliferated together with corresponding search (recall, retrieval, associating and selecting) procedures.

STORED INFORMATION (PERCEIVED CONTENT)

Much of what we are storing includes semantic information, that is information which consists of words and is about words, information relating to what words mean and imply.

And images, that is scenes, including events and sequences of events, and their components.

Including what happened, when it happened and the sequence in which it happened.

People with an eidetic (image-retaining) memory remember images, often clearly and in detail <1>. "Many, if not all, young children apparently do normally see and remember eidetically, but this capacity is lost to most as they grow up. What is in young children an apparently general capacity has become a remarkable rarity in adults." {6}

The information one receives may be fact or fiction, right or wrong, intended to inform or to mislead, understood or misunderstood. Even so, what is stored is the perceived content of the received information.

LEARNING (MEMORISING) AND UNDERSTANDING

Rose defines an animal's learning by "learning is a response by an animal to a novel situation such that, when confronted subsequently with a comparable situation, the animal's behaviour is reliably modified in such a way as to make its response more appropriate" {6} <3>

Pointing out that human memory is very different from that of a non-human animal, Rose says that "procedural memory dominates the lives of non-human animals, ... but declarative memory profoundly shapes our every act and thought." Our memory includes a verbal memory which "means the possibility of learning and remembering without manifest behaviour."

But our memory consists of much more than just verbal memories.

Continually associating new information with older information, and older information with other older information, is much more than random cross-referencing.

It is because of the meaningful way in which we associate over such large volumes of stored information, that the process of associating amounts also to the seeking of meaningful associations.

So to me it seems that all the information we take in and retain results in a more comprehensive view and deeper understanding of the world in which we live, of our social organisation and physical environment. Thus, in the end, at some time and in some way, the information we have taken in affects and changes what we do, changes our behaviour.

DEVELOPMENT OF BRAIN FUNCTIONS IN HUMANS

Development of Brain Functioning in Foetus and Newborn

Rose describes how the human brain develops before and after birth, saying "Early brain development in the foetus and newborn is itself associated first with a massive proliferation of cells, and then by a steady drop in numbers, but the space once occupied by the lost cells is taken up by an increase in the branching and synaptic connections made by those that remain."

Role of REM Sleep in Infants

Lavie pointed out that in animals which are born fairly mature, such as sheep, REM sleep is low and near adult level. In species which are born immature, "such as rats, cats, and humans, initial amounts of paradoxical (REM) sleep are very large. In kittens, during the first ten days of life paradoxical (REM) sleep occupies 90 percent of their time." {10}

We already saw that Jouvet hypothesised that one of the roles of REM sleep in animals was to train the neural networks which are related to instinctive behaviour.

We also saw that during the first few days after birth the actual amount of REM sleep in babies is very great and Lavie concluded that "it plays a vital role in the maturing stage of the nervous system" and that "it is possible that REM sleep is particularly important for procedural types of learning in which humans acquire motor and perceptual skills. Since during the first few months of life infants are busy acquiring new motor and perceptual skills, these findings may also explain the abundance of REM sleep at that particular time in our life". {10}

Stevens {4} says "REM sleep is thought to play an important role in developing the infant brain and in activating those neural programmes responsible for basic and characteristic patterns of behaviour, such as maternal bonding, environmental exploration and play."

He added that common childhood fears "of the dark, of strangers, of rapidly approaching objects, are all ... early warning devices put there by evolution because of the constant dangers in the ancestral environment".

Children do not distinguish between dreams and waking life until they are three or four years old, but can usually understand the difference when between five and eight years old.

Changes in Sleep-wakefulness Rhythm during First Year of Infant's Life

A baby wakes and sleeps roughly every four hours in its first month. This changes gradually until at about six months "the baby begins sleeping almost through the night and the sleep-wakefulness rhythm stabilises at twenty-four hours". And so during the first year "a single and continuous sleep period and a period of continuous wakefulness begin to emerge, and at the same time a pattern of coordination between the sleep-wakefulness rhythm and the demands of the external environment slowly begins to develop". {10}

Lavie notes that it is during the first months of life that the longest duration of REM sleep occurs and that this coincides with the time when sleep becomes consolidated into a single and continuous sleep period.

Learning by Playing and by Experience

Playing is a way of learning how to behave, of learning about social co-operation and conflict, about family relations and about bringing up a family.

Social responsibility, the caring, giving and sharing with others, the taking on of responsibility for others, including conflict management, can be and is being taught. {15}

From infant through child and adolescent to being an adult, we go through a long period in which we learn through playing and by experience, and also absorb information from external memory, from the mass of information now available to us from sources external to ourselves.

And learning by experience and by gaining knowledge continues while we are alive. Each new experience adds to our knowledge and plays a part in shaping our view of the community and society in which we live, of the world at large, and helps to determine what we do and how we do it, helps to determine our behaviour.

Change from Eidetic to Linear Memory

We already saw that many, if not all, young children apparently do normally see and remember eidetically <1>, but that this capacity is lost to most as they grow up.

Rose considers that at birth all types of input are likely to be seen as about equally relevant, that all input is registered and ordered "so as to enable each individual to build up his or her own criteria of significance". Eidetic memory gives equal importance to all inputs so that all inputs are analysed, are processed and stored.

It seems that children remember everything. But at some time before puberty most of us cease to remember eidetically, 'there is for most of us a transition in how we perceive and remember the world ... as we consciously or unconsciously learn to select salient information that we need to commit to memory from the environment around us." {6}

CONCLUSIONS - BRAIN, MIND AND BEHAVIOUR (Human Behaviour and How The Mind Works)

INSTINCTS AND INSTINCTIVE BEHAVIOUR

We saw that instincts are an innate form of behaviour, that is a form of behaviour which is not learned but which the animal performs from birth, without being trained to do so.

Behaviour relating to survival of a species, such as attack, defence and sexual behaviour, is instinctive and responses are automatic. Territory is acquired by force and defended. Might is right.

CONSCIOUS BEHAVIOUR: LEARNING AND EVALUATING, MEMORY AND MEMORISING

As mammals evolved from reptiles, there evolved the ability for storing new experiences as they happen and so creating a store of experience-based memories.

A primitive animal's memory seems to be largely procedural. Both procedural and declarative memories are long-term memories, but declarative memory is located and used in a different way.

Human beings are learning all the time, memorising information and then recalling it when it is required.

What is being memorised includes what we are taught, what happens to us and to others and any lessons learned as a result. And when it happened and the sequence in which it happened. Including also the meaning of words and what is implied. And in addition we have the vast mass of externally prepared and stored information which is accumulating at an accelerating pace.

Massive volumes of information are being received. The incoming information is evaluated and we memorise only information which seems to matter. Some is retained, the rest rejected. Retained short-term (working) memories are converted to long-term memories. So only a part of the incoming information is retained and stored, that is memorised, so becoming available for recalling later when required.

Aspects of memories <9> are stored in different locations. Aspects such as colour, shape, event, phrase, place, time, date. Aspects like shape of face, sound of voice, colour of hair.

Memories are associated, crossindexed if you like, with their different aspects and can be recalled by recalling an aspect associated with the memory one wishes to recall. Component memories are continually being associated with other old or new component memories, enormously increasing the range and flexibility of what can be recalled.

A process which continually keeps available memory components which relate to those of current interest, and memory components which are more frequently used than others.

Human beings store memories by means of changed neural pathways, by means of persistent modifications to the structure of neurons and their synaptic connections, by means of biochemical changes. {6} <3>

So we are strengthening neural pathways or associations by frequently using or recalling them, weakening memory components which are not being used.

Hence using neural pathways holds memories at higher, more easily accessible levels of memory, makes them more readily available. Infrequently recalled memories would seem to be overlaid by more frequently used ones, seem to be reduced to lower levels of awareness, of accessibility.

COMMUNICATING NON-VERBALLY: CONVEYING INFORMATION BY USING IMAGES

Instinctive Behaviour

Dreaming trains animals and human beings in instinctive responses and then keeps instinctive behaviour fully trained.

Dreaming does so by generating situations which require responses of the fight, flight, affection kind. A dream produces a corresponding response which, however, is not translated into action as the dreamer's body is normally paralysed by the mind for duration of dreaming (REM) sleep.

Frequent replaying strengthens corresponding neural pathways and so trains the individual to respond and to respond quickly.

Subconscious Behaviour (Functioning)

As mammals evolved from reptiles, the added functions included organs such as the autonomic nervous system for the automatic control of body functions, of functions such as digestion, the fluid balance, body temperature and blood pressure.

A key finding of this report is that the right hemisphere of the human brain is able to communicate by using images with the brain's older and more primitive component organs which have no verbal skills. And this enables us to communicate intentionally (that is 'consciously') with our autonomic nervous system and ask it by visualising to control body functions and to affect our body's immune system. Any or all our senses can be included when visualising.

Clinical trials have shown remarkable success in areas such as the treatment of cancer and heart disease.

Communicating with one's autonomic nervous system by visualising is a conscious activity.

Hence it is possible to direct and use the mind's subconscious maintenance and control capabilities, and so enable environmental experience and knowledge to be applied for one's benefit. That is, one's knowledge and experience can be consciously applied towards modifying the mind's subconscious control of body functions for the benefit of the individual.

Memorising

It is while REM sleeping that dreams are generated and that we appear to be filing away (memorising) memories for later use.

Much of dreaming may then be the creating and recalling of associations. As the night progresses this process seems to become more intuitive, delving deeper into stored memories and associations, associating with earlier memories and their aspects, tending to go back in time towards childhood.

Becoming more intuitive by going through likely or apparently associated filed images or other stored memory components (aspects) in their different locations.

In this way keeping long-term memories intact and relevant by continually associating and reassociating their various parts.

So we are strengthening neural pathways or associations by frequently using or recalling them.

This process at the same time would seem to weaken those memory components we are not thinking about or which are not being used.

ADAPTING TO THE ENVIRONMENT: CHANGING INSTINCTIVE BEHAVIOUR

A key feature which distinguishes mammals from the reptiles from which they evolved would seem to be that the mammalian brain contains organs for the experience-based recognition of danger and for responding to this according to past experience. And for some conscious feelings about events.

Millions of neural pathways connect the organs which generate experience-based memories, and also those which generate conscious feelings with associated behavioural response patterns, to the reptilian parts of the mammalian brain.

It seems that feelings such as attachment, anger and fear have emerged with associated behavioural response patterns, and that behaviour is less rigidly controlled by instincts.

So it seems that instinctive behaviour can be modified by feelings of care and affection and also by experience, particularly when repeated frequently.

Neural pathways are created and strengthened by being used, others weakened by not being used. We react accordingly and it seems as if memories are being created which modify instinctive behavioural responses.

It also seems that instinctive behaviour has to be controlled, and modified according to the environment in which we find ourselves, in every generation, and that the mammalian and human parts of the brain play a major part in this.

ADAPTING TO THE WORLD IN WHICH WE LIVE: CHANGING BEHAVIOUR PATTERNS

We adapt to the world in which we live in much the same way. What happens to us and what we do, and what happens as a result, changes neural pathways. A trace is left, neural pathways are changed, memories are formed.

Playing is one way of learning how to behave, of learning about social co-operation and conflict, about family relations and about bringing up a family. From infant through child and adolescence to being an adult, we go through a long period in which we learn through playing and by experience. And learning by experience and by gaining knowledge continues while we are alive.

Social responsibility, the caring, giving and sharing with others, the taking on of responsibility for others, including conflict management, can be and is being taught.

What human beings do, what happens to us, is also memorised if thought relevant. These memories can be recalled when required and in this way will affect our future behaviour.

Additionally we also absorb information from external memory, from the mass of information now available to us from sources external to ourselves. And the action we take, what we do, depends on evaluating the situation, what we know and how we feel about it. The outcome itself is evaluated and becomes part of our memories.

It seems that on the whole people may not be able to recall feelings, that most people can only recall how they felt about something at the time.

Each new experience adds to our knowledge and plays a part in shaping our view of the community and society in which we live, of the world at large, and helps to determine our behaviour.

EVALUATION AND UNDERSTANDING

Behaviour of the primitive animals from which human beings evolved is instinctive. Which means that behaviour relating to survival, such as attack, defence or sexual, is automatic. Territory is acquired by force and defended. Might is right.

The mammalian brain includes the older reptilian brain and is linked to it. With the mammalian brain emerged feelings such as attachment, fear and anger together with associated behavioural response patterns. Mammalian behaviour is less rigidly controlled by instincts.

The human brain (see Figure 3 'The Human Brain') includes the mammalian brain and human emotional responses depend on neuronal pathways which link the right hemisphere to the mammalian brain.

It takes human beings many years to bring up their children and it is the right hemisphere which is concerned with a wide range of emotions and feelings of care and affection for the young and for the family, and then for other people and the community.

Figure 3 The Human Brain

Back to Contents list

For human beings, primitive (reptilian) instinctive urges and behaviour are overlaid by mammalian care and affection for one's young and human care and affection for one's family and community. Behaviour is aimed at survival of the young and of the family, and then is for the good of family, other people, community.

The right hemisphere is linked to the primitive older part of the brain which has no verbal, semantic or reasoning ability and so functions subconsciously (below the level of consciousness). Hence the right hemisphere communicates with the 'subconscious' functions of the older part of the brain by using images. Communicating by using images is fast.

And so the right hemisphere communicates using images (pictures) and has highly developed spatial abilities, is intuitive and imaginative, is concerned with emotions and feelings.

Speech, that is thinking and communicating by using words, seems to have evolved later. The left hemisphere communicates by using words, has highly developed verbal and semantic abilities, is logical and systematic, concerned with matters as they are. Images may be described, or transformed into a narrative, by the left hemisphere.

Hence behaviour is not only determined by feelings but also by knowledge, understanding and reason.

So the human brain includes the processing and memorising of images and of their components, and the development of language and corresponding mental processing connected with memory and memorising. It also includes a wide range of emotions, of feelings, of care and affection, and the capability for objective and logical thinking and evaluation. And the later development of written languages and artificial images.

We are continually gaining information by learning, by reading or studying, learning from the experiences of others, gaining verbal information and pictorial images from external memory. The mind evaluates this incoming information and decides what is to be retained and memorised, rejecting the remainder. Information about what has been happening to oneself is treated in the same way.

And when something is happening to oneself, when one is doing something or planning to do something, we recall relevant information from memory, add other available information, and before taking action we evaluate all the information we now have. What happens as a result of the action we took is again evaluated and memorised for later use.

So we are continually evaluating information and this is a key feature of the human mind. Evaluation means estimating significance, relevance and reliability. In other words, estimating meaning and importance, bearing on or reference to the matter in hand, whether it can be relied on. In this way continually becoming more aware of explanations and causes, gaining understanding.

We memorise both verbal and image information. However, we do not memorise feelings, possibly because they may originate within the earlier mammalian parts of the brain . What is recalled is how we felt at the time, the actual feeling is not reproduced, cannot be recalled.

And memorising images is fast and this would seem to apply to their component parts and to associating. The eidetic memory of young children usually changes to linear memory as they become more adult. It appears that as we grow older so we start evaluating and then cease merely to take in such information as we come across. As we become adult we start to evaluate and develop and extend our evaluating skills. In other words, as adults what we memorise and how we recall and use recalled information is then governed by reason and aids understanding.

Continually associating new information with older information, and older information with other older information, is much more than random cross-referencing.

It is because of the meaningful way in which we associate over such large volumes of stored information, that the process of associating amounts also to the seeking of meaningful associations.

So to me it seems that all the information we take in and retain results in a more comprehensive view and understanding of the world in which we live, of our social organisation and physical environment. And thus, in the end, at some time and in some way, the information we have taken in affects and changes what we do, changes our behaviour.

THE STRUGGLE FOR A BETTER LIFE

When identical same-sex twins are brought up in exactly the same environment and treated exactly the same (clothing included), they usually behave and feel much the same.

But identical same-sex twins brought up as individuals have different personalities, are different people. Usually one is more dominant while the other is more emotional.

It is apparently easier for people who are 'cold and calculating' to be dominant, to dominate those who are 'emotional'.

Add that those dominating others may in this way acquire power over others, or social and economic gains from using, and from misusing, people.

Such a system rewards primitive inhuman brutal (beastlike) behaviour (acquiring territory by force, might is right), held in check only by the fear of consequences.

We also see that dominating others is conditioned, that is unnatural, behaviour which is destructive of humane behaviour. A throw-back to the level of the unthinking unfeeling primitive animal.

Humane behaviour is based on feelings of care and affection for the young and for the family, and then for other people and the community. From this emerges a sense of social responsibility: people matter and are important, need to be treated well and looked after, are entitled to share equally. Backed up by knowledge, understanding and reason.

And, in the hostile environment in which humanity finds itself, what is also needed is dedicated effort, strength and power to achieve a humane way of living, to achieve a good standard of living and a high quality of life.

Part of the hostile environment is an almost intentional-seeming conditioning which frequently portrays brutal behaviour as a norm, by media and other opinion-forming sources. This has the effect of brutalising society, seemingly legalising, making acceptable, inconsiderate and unfeeling behaviour towards other people.

What we see is a world-wide struggle for a humane life {8, 9} which shows people struggling to achieve a humane way of life, each struggling to advance at their own level of development and achievement, struggling against those who wish to dominate others, against those who wish to exploit others, against those who wish to oppress so as to exploit.

Struggling to achieve the satisfaction of needs which are entirely in line with what we have seen here in this report about the evolution and development of the human brain and human mind. Needs and wants such as those for survival (food, shelter, clothing) and secure existence, affection and esteem, friendly and trustful co-operation and companionship, independence from domination by others, high quality of life and living, self-realisation and development. And "people will co-operate with each other and work hard and well to satisfy these needs and gain much satisfaction from doing so". {8, 9}

MAIN CONCLUSIONS

As a result of the work reported here there has emerged a much clearer appreciation of what happens during the course of a night's sleep, and clear explanations of the role of dreaming and the meaning of dreams.

The report explores the functioning and role of the two halves of the human brain and the relationship between them. It is the right half which usually communicates with the primitive parts of the human brain.

A key finding of this report is that the right hemisphere of the human brain is able to communicate by using images with the brain's older and more primitive component organs which have no verbal skills. This enables us to communicate intentionally (that is 'consciously') with our autonomic nervous system and ask it by visualising to control body functions and to affect our body's immune system. Any or all our senses can be included when visualising.

Hence it is possible to direct and use the mind's subconscious maintenance and control capabilities, and so enable environmental experience and knowledge to be applied for one's benefit. That is, one's knowledge and experience can be consciously applied towards modifying the mind's subconscious control of body functions for the benefit of the individual.

The report also relates the functioning of the brain to behaviour, showing to some extent how human behaviour is affected by the primitive instincts of our reptilian ancestors.

NOTES AND REFERENCES

NOTES

REFERENCES

Relevant Current and Associated Works

Back to Contents list

Relevant Subject Index Pages

• Press Notices
• Motivation
• General Management
• Community
• Economics

Other Subjects; Other Publications

• Christianity
• Judaism
• Islam
• Religion, Government and People
• Teachings

The Site Overview page has links to all individual Subject Index Pages which between them list the works by Manfred Davidmann which are available on the Internet, with short descriptions and links for downloading.

To see the Site Overview page, click Overview

Back to Contents list

Copyright    ©    Manfred Davidmann    1998, 2006
All rights reserved worldwide.

Updated   2021  -  the following links were added:
TERMS OF USE
THEME OF THE WEEK
About Manfred Davidmann and his Works
BOOKS
Donations
Privacy Notice
Contact form