Bilateral Course (2)

The Two Sides of the Brain

By the beginning of this century it was known that damage to certain areas of the left hemisphere results in the loss of speech, poor reading, and a general deterioration in logical thinking, whereas damage to the corresponding regions of the right hemisphere produces a deterioration in visual and spatial functions, such as the recognition of faces and the ability to dress oneself.

The split-brain experiments

In the 1960s Roger Sperry, at the California Institute of Technology, began extensive studies on a number of epileptic patients whose corpus callosum had been severed. This operation had been administered in order to confine a seizure to one half of the brain, so that the other half could carry on functioning normally, enabling the person to take some medicine or summon assistance. In his research, Sperry began to uncover some interesting anomalies.

If a patient was given something to hold in his right hand, he could say what he was holding, since the information was going to the left (verbal) side of the brain. But if the object was in his left hand, he could not describe it, he could only make a guess - though he could later point to the object again with his left hand, knowing intuitively, since the right-brain had both recognized and remembered the object.

The crossover in the visual system is slightly more complex than in the rest of the body. The eyes themselves are not directly crossed, but the left side of the retina of each eye connects to the left side of the brain, and the right side of the retina of each eye connects to the right side of the brain. Thus, since the retinal image is inverted, the left side of the visual field connects to the right side of the brain and the right side of the visual field connects to the left side. This gave rise to some interesting phenomena in the split-brain patients. If the word HERMAN were flashed to a patient in such a way that his focus lay between the R and the M, the first three letters would go to the right hemisphere and the last three letters to the left hemisphere. When asked to say what he had seen, he would reply 'MAN'; but when asked to point with his left hand to what he had seen, he would point to the word 'HER'.

The reason that such differences had not been found in earlier, more superficial studies, was that the two halves of the brain had been able to communicate in other ways. In one of Sperry's experiments a light was flashed in the left visual field so that it arrived in the right hemisphere, and the patient had to say whether the light was red or green. At first the replies were purely guesswork, the left hemisphere having no idea what the right side was seeing, but after a few trials the patient began correcting his mistakes. The left hemisphere might wrongly guess 'red' for a green light, but the right hemisphere, on hearing the wrong answer, would start shaking the head and making frowns. The left hemisphere, responding to this discomfort, would immediately say, 'Oh no, I meant green!' Once such conflicting sources of information were controlled in Sperry's experiments, the different functions of the two hemispheres began to become more apparent.

In another test that demonstrated the right brain to be better at special problems, a patient was given several wooden shapes to arrange to match a certain design. His attempts with his right hand (left hemisphere) failed again and again. His left hand (right hemisphere) kept trying to help. The right hand would knock the left hand away, until finally, the man had to sit on his left hand to keep it away from the puzzle! When the scientists eventually suggested that he use both hands, the spatially capable left hand had to shove the incompetent right hand away, to keep it from interfering, as he easily completed the puzzle.

Such tests, then, provided surprising new evidence that each hemisphere perceives reality in its own way. The verbal half of the cortex - the left half - dominates most of the time in individuals with intact brains as well as the split brain patients, whether they are left handed or right handed (handedness is controlled by the cerebellum, a deeper level of the brain than the thinking cortex). But Sperry's evidence indicated that the right, non-speaking half of the brain experiences, responds with feelings, and processes information on its own. In our own brains, with intact corpus callosa, communication between the hemispheres melds or reconciles the two modes of perceptions, thus preserving our sense of being one person, a unified being.

specialization of function

The two types of thinking are summarised in the following table:

The different functions of the two hemispheres have been confirmed by comparing the electrical activity from the left and right sides of the brain. When the brain is in a relaxed state, it tends to show Alpha rhythms, i.e. waves of about 8-12 Hz. When a subject is given a mathematical problem to solve, the alpha increases in the right hemisphere and reduces in the left, suggesting arousal is being focused more in the left hemisphere. Alternatively, when the subject is asked to match colored patterns, the reverse occurs, indicating that the subject is making greater use of the right brain.

Brain wave studies also indicate that for perhaps 90% of people (including left handers) the left hemisphere is dominant, i.e. it is somewhat more electrically active or 'aroused' than the non-dominant one, and the individual relies on that hemisphere more than the right. The other 10% of people are more likely to be left handers but not necessarily so; a more significant factor is their inherited inclination, their upbringing and the nature of their work and lifestyle. Everybody, however becomes temporarily more aroused in either of the hemispheres corresponding to the particular mental activity that they are doing or experiencing. The Bilateral Meter may be used to measure these differences of arousal in association with specific mental activities.

When it comes to the more abstract forms of thought, the left and right hemispheres of the brain operate in remarkably contrasting ways. The left brain deals primarily with information which can be represented in sequential or linear form, such as sequences of sounds, words and sentences, abstract symbols numbers and logical 'if-then' relationships. And the left-brain is more specialized in serial processing, i.e. processing information one bit after another, in logical chains of reasoning (particularly in terms of differences), and time relationships. For example in writing, one takes an idea and verbally analyzes its meaning into the form of sentences, then one breaks these down into grammatical phrases, the words of which are written down one letter after the other.

Meanwhile, the right hemisphere deals with whole forms, especially visual and spatial structures, rather than elements in a sequence. The right brain is more specialized in parallel processing, i.e. taking several bits of information simultaneously, noticing similarities and making a synthesis of them. For example, in forming an idea, the person takes a number of related concepts, connected in a spatial network (usually with images and feelings), and synthesizes them into a whole, communicating this to the left brain in an intuitive form as an idea, for analysis by further association, development and verbal description.

The left brain is also responsible for selective attention, which converges inwards towards the selected foreground figure, such as a particular phrase or meaning or object. The right brain, in contrast, provides a contextual awareness of all else that is going on, diverging outwards to encompass the background or peripheral field. There is, then, a 'figure and ground' relationship, the left dealing with a subject (one after another) and the right providing a (relatively stable) context in which it may be understood.

A person almost totally unable to take an overview was described by Luria, the great Russian neurologist, in his book 'Man with a Shattered World'. He talks of a soldier who received a bullet wound that severely damaged the right side of the brain, yet the man survived. However there were very strange consequences. For example, whilst eating soup, when he concentrated on the soup, the spoon disappeared; when he concentrated on the spoon, the soup disappeared; and when he concentrated on the flavour, the whole room disappeared. The left hemisphere is organized to deal with one detail at a time, whilst the right side deals with many details simultaneously, and provides the context. Both sides, though, process a great deal of information sub-consciously, i.e. without the necessity for conscious control.

In playing music, the left hemisphere can only deal with one note at a time, albeit in quick succession, whereas the right looks at the overall context: that which has gone before and in anticipation of what will happen, as the music unfolds. A person without a right hemisphere could tune a guitar, and play notes that are written down, in a robotic way. Whereas with the cooperation of the right side of the brain, the melody line and chordal structure of the whole piece are intuitively grasped, there is aesthetic appreciation and interpretation, and the player may easily translate intention into action at the non-verbal level. Both types of consciousness are necessary, in most activities.

A person's right hand controls fine detailed movement such as writing, adjusting mechanisms, controlling tools, or doing anything which requires sequential actions. Whereas the left hand establishes an anchor point, a reference in grounded reality: a fork secures the food whilst the knife cuts it. Playing the guitar, the left hand holds down a fixed length of string whilst the right hand plucks it. You might say that the left brain is the chalk and the right brain is the blackboard, when both sides of the brain are working together.

Often people can be described as left brain dominant or right brain dominant: for example, artists tend to be right-brained and mathematicians left-brained. It is unlikely you would find a person that was totally left or right brain dominant outside of an institution: such a person would find it impossible to survive. The most able people however, can easily switch from one type of thinking to the other, as their situation demands. Most people, however, will have an imbalance, in one direction or the other, usually to the left. In many cases a person would benefit through a job or activity that would place some stress on the under-used side of the brain. A large part of Mental Development is directed at helping Students to gain ability in both types of thinking.

We have learnt that the two hemispheres work in different ways that complement each other. Sometimes they co-operate, with each half contributing its special abilities and taking on the particular aspect of the task that is suited to its mode of processing. At other times the hemispheres can work singly, with one half 'on', the other half more or less 'off'. But the hemispheres may also conflict, one half attempting what the other half 'knows' it can do better. Often the dominant left hemisphere will 'take over' and inhibit the right. Furthermore, each hemisphere may suppress information from the other hemisphere that it considers to be unwelcome.

The integrated brain

The combined use of both the right and left hemispheres is a common characteristic of the creative process, whether in science or in the arts. Leonardo da Vinci was as much scientist as artist, an engineer and architect as well as sculptor and painter. His notebooks reveal concise analytic thinking combined with deep insight and aesthetic appreciation.

The history of science is replete with anecdotes about researchers who repeatedly try to figure out a problem, and then have a dream in which the answer presents itself as a metaphor that is intuitively comprehended by the scientist. Using the right hemisphere, we dream, we perceive metaphors, we recognize analogies, we identify related items, we create new combinations of ideas. We produce intuition and have leaps of insight - moments when 'everything seems to fall into place' without figuring things out in any logical order. When this occurs, people often say, 'Ah-ha, now I've got it!' or 'Ah, yes, now I can see the picture', like the exultant cry by Archimedes of 'Eureka!' when he realized the principle of using the weight of displaced water to determine the upthrust of floatation, whilst he was in the bath!

The theory of relativity was born when Einstein was lying on a grassy hillside one summer's afternoon. He was gazing up at the sun through half closed eyelids, playing with the light that passed through his eyelashes, when he began to wonder what it would be like to travel down a light beam. Then, almost in a flash, he realized what it would be like. This realization had come to him not as a logical deduction, but as a creative, intuitive insight. It was the result of a synthesis of all of his prior organized knowledge and understanding, and he was able to grasp the intuition because he was both open to communication from the right hemisphere, and also he had the appropriate analytical tools in the left hemisphere to be able to appreciate the insight, and develop it into a logical theory.

As Einstein described: 'I will do a flight of fancy and work on some thinking, which is not thinking as is commonly understood, but a concurrent play of images and sensory feeling. Only when this activity comes to some resolution, would I fumble in the other side of my head, for the words and algebraic statements which would permit me to communicate these insights to others.' True thinking, which stands behind our conscious thinking, is nonverbal. A person who is fully aroused in the right hemisphere, when both hemispheres are co-operating, uses words as his servants; whereas a person who is left brain dominated, tends to be governed by words, belief systems and symbol systems, often to the exclusion of objective reality.

Both in children and primitive people, the degree of differentiation between the two sides of the brain is slight. According to the German philosopher Ernst Cassierer, many primitive people are unable to tell a lie, because this requires standing outside of oneself, to have an abstract perspective, so one can have feelings about one's thoughts, and thoughts about one's feelings. A person with specialized but integrated hemispheres is able to have this abstract perspective, so lying is something he can do easily. When we write a story or invent something, initially we are telling a lie: something that conflicts with reality.

The problem arises when the left hemisphere creates an idea but is not sufficiently in communication with the right hemisphere, in order to know that the creation is fictional. The person has then lied to himself, perhaps wilfully so in defiance of reality, or perhaps as a result of suppression of an unacceptable reality perceived by the right hemisphere, such as painful experience or personal bad actions.

According to depth psychologists such as Janov and Bianco, we may retreat into left brain modes of perceiving and acting, in which our emotions are memory rather than what is directly experienced, because traumatic material is being suppressed in the right side of the brain and is effectively inaccessible. By splitting the storage of memory in this way, we have a verbal description of the events we can access, but we are unable to experience the pain and emotions of the memory.

Another person who is in the right brain, may well have pain, emotion and effort visible, however he is unable to process the verbal material in the left, such as decisions, conclusions and resulting beliefs, as this side of the brain is suppressed below the boundary of consciousness. This may occur, for example, when a person is in a state of extreme emotion, such as love, rage or grief; the words to express this either do not come easily or they do not come at all. This, then, is the issue of personal integrity, and it is the keystone upon which hemispheric integration either deteriorates or becomes possible.

The Psychological Background

This operation can come about through double-bind situations in childhood. The following quotation is from a paper by Ernest Rossi entitled 'The Cerebral Hemisphere in Analytical Psychology' published in the Journal of Analytical Psychology, January 1977.

"Imagine the effect on a child when its mother presents one message verbally, but quite another with her facial expression and body language. 'I am doing it because I love you, dear,' says the words, but 'I hate you and will destroy you' says the face. Each hemisphere is exposed to the same sensory input, but because of their relative specializations they each emphasize only one of the messages. The left will attend to the verbal cues because it cannot extract information from the facial gestalt efficiently; the right will attend to the non-verbal cues because it cannot understand the words.

"...In this situation the two hemispheres might decide on opposite courses of action: the left to approach, and the right to flee. Because of the high stake involved, each hemisphere might be able to maintain its consciousness and resist the inhibitory influence of the other side. The left hemisphere seems to win control of the output channels most of the time, but if the left is not able to 'turn off' the right completely, it may settle for disconnecting the conflicting information from the other side. The mental process in the right hemisphere, cut off in this way from the left hemispheric consciousness that is directing overt behavior, may nevertheless continue a life of its own. The memory of the situation, the emotional consequences, and the frustrated plan of action all may persist, affecting subsequent perception and forming the basis for expectations and evaluations of future input."

The reader can understand how variations of such inter-hemispheric conflict could serve as the neuro-psychological basis for such psychodynamic concepts as dissociation, perpetual defense and repression.

Conflict may also manifest itself at the RAS (Reticular Activating System) level of the brain. To quote Norman Dixon of University College, London, the brain can elaborate conscious experience such as dreams and hallucinations in the absence of external stimuli, and it can also receive, classify and respond to sensory information without such data penetrating into consciousness. However, he found that if a repeated stimulus finally results in conscious awareness, then the RAS had been activated. One may filter from the perceptual stream the sound of a loud clock ticking in the background, but then suddenly become aware of it and find it distracting. Consciousness is a limited capacity system and needs to be used to maximum advantage. Limiting inflow of data would be detrimental, but suppose the brain could maintain a variable restriction on what enters into consciousness, then the organism could have its cake and eat it too. Dixon believes that the experimental data suggests that at some preconscious stage of the perceptual process, the brain detects the meaning of the incoming information and then initiates an appropriate change in the level of its sensitivity from the RAS level. Important, meaningful data are more likely than trivial information to achieve conscious representation.

The preconscious mechanism of selective attention is an important factor to be aware of, in the use of GSR and Bilateral Meters. The first, below conscious reaction of the meter to a stimulus (such as a reactivative word or concept) is represented on the meter after a minimum delay of 0.2 second - this time lag is limited by the small size of the nerve fibres which conduct the impulse to the hand, but this factor also varies proportional to the subjects speed of nervous response, which is directly related to IQ. The energetic response is provided by the RAS, which interacts with the cortex; the stimulus is considered worthy of attention and the cortex is Energized - this is registered as a change of arousal by the GSR Meter. The degree of differential arousal between left and right hemispheres is measured on the Bilateral Meter. A particular question may activate both hemispheres of the brain. The Bilateral needle moves to left and right as though each hemisphere is saying to the other 'not my province, over to you.' Such responses may be seen to questions such as 'can there be a scientific basis for astrology?' or 'consider death.'

In negative (unpleasant) states of high arousal, attention tends to focus narrowly and to be trapped by the source of concern. By and large, negative states of high arousal tend to reinforce left-brained types of awareness. This may reverse in people with a very poor case state, as in the psychotic person, or under extreme stress and overwhelm.

The distress of negative arousal stems from trauma. The individual who is free of traumatic blocks, has a range of states representing a change from BP 2.2 - 3.8 on the GSR Meter, and from 4 to 6 on the Bilateral balance scale. Somebody with severe traumatic affects has a small free space on the GSR - a stuck needle. Above this point he feels gloomy and below this figure he feels cross. With this kind of double-bind, he is well on the way to schizophrenia. Similarly, a person rigidly fixed on the Bilateral scale will experience cognitive and emotional distress in many situations.