Behind the Scenes of The Brain Show
Page 44
In his opinion, the mental sphere of each of the hemispheres is where the perception processes, which are totally different from the perception processes of the other hemisphere, take place. This hypothesis can be defined as “mental duality”—two minds live within one brain or, alternately, two souls share a single boardinghouse.
It seems that the cutting of the corpus callosum leads to flattening of the overall intensity of the experience of perception impressions. This suits the saying “The whole is bigger than its parts.” The overall experience is bigger than the sum of its processing in each hemisphere separately. Processing an experience in the “two different minds,” from the left and from the right, adds a dimension of depth; on the other hand, cutting of the connecting pathways between the two hemispheres flattens the depth of experience.
Why Did I Laugh?
During an experiment that was conducted on a person whose corpus callosum was cut (“split- brain”), a request, written on a piece of paper, was presented to this person: “Laugh!” The message was presented only to the left field of vision, which channels visual input to the right hemisphere. The patient started laughing in response. When he was asked to state the reason for his laugher, however, he fabricated one. The request to laugh was absent from the visual world of the left hemisphere. Due to the cutting of the main channel of communication between the hemispheres, the corpus callosum, the only addressee of the request, was the right hemisphere. It seems that in the absence of information, the left hemisphere came up with a fabricated story to explain the subject’s laughter. Brain researcher Michael Gazzaniga believes that the right hemisphere is the ideal witness; it always tells the truth and nothing but the truth and does not “fill in the gaps” in our perception with false “findings.” On the other hand, the left hemisphere tends to ease the discomfort that is involved in partial understanding by creating fictional reality details that never actually happened, although they sound plausible and appropriate.
Fabrication From the Left in Action
In an experiment that was conducted among subjects who were questioned after going through hypnosis, it was found that, when they woke up, they did not remember undergoing conditioning, in which a certain command by the hypnotizer led them to perform a certain action, such as retying their shoe laces. When the sentence was said and the conditioning worked and led them to tie their shoelaces, they explained it by providing reasons that seemed plausible, such as the long walk that awaited them until they got home, and their wish to make sure that their shoes were up to it, by using ad-hoc rationalization. It seems that the left hemisphere came up with an appropriate “cover story,” since it was unaware of the hypnosis conditioning.
Imprisoned Melody
The stroke that composer Maurice Ravel suffered in the summer of 1933 took away his god’s gift of composing music. He lost the ability to conceptualize his musical ideas in the language of notes. The ability to listen to music and be moved by it was not taken away from him, however, which was comforting in a sense. We might say that his injury was like a mirror image of the deafness of Beethoven, who lost the ability to listen to music but whose composing ability remained intact.
A plausible assumption is that Ravel suffered damage in his left hemisphere, which conceptualizes our thoughts as symbols and turns musical ideas into formal symbols (notes), while the right hemisphere, in which the music experience is perceived as a whole, was probably not injured.
Part B: The Seasons of the Brain—Changing of the Brain in Different Periods of Life—How Does Our Brain deal with the Different Stages of Life?
Chapter 13: Patterns of Brain Function in Different Periods of Life
Change Fixation
The brain, like Heraclitus’s river, is ever changing.
Like Heraclitus’ river, each experience that is processed by our brain changes it for good. Reality never encounters an identical brain twice.
The view of our mental world changes constantly. The key concepts in this process are continuous acquisition of world knowledge, and the skills that are necessary for making changes in this knowledge, alongside changes in brain structure and function. The information processing approaches of our brain are prone to change in various stages of our life. This is the “flick-flack” of our learning pendulum.
During early childhood, we tend to study the world by means of overgeneralization. Later on in life, we learn how to notice the nuances and various shades; in old age, it seems that many of us tend to regress to overgeneralization when interpreting world phenomena.
Our brain reacts differently to stimulations in different periods of life.
In each period of life there is a mix of different neurotransmitters that characterizes it and in light of which (or at the shadow of it) our brain functions.
Age-dependent hormonal changes also force upon our brain a new version of its marriage contract with reality perception.
The changing seasons of the soul also color, in their typical color, our inner emotional climate, which changes throughout life and affects our “emotional personality.” In this sense, there are different “seasons of the emotions” throughout our life.
Age-Dependent Activation Software
The pattern of activating thinking skills changes over the years. With the climbing of the year’s ladder, as we grow older, the mountain of life insights becomes taller, and the method according to which we cope with information relies more and more on pattern identification. On the other hand, thinking functions, such as the ability to split attention, to focus attention for a long period of time (mental resistance), to avoid distractions, and to assimilate new information, become weaker.
Using different brain areas is related to age-dependent characteristics. Brain scans show that between adolescence and young adulthood (ages fourteen to thirty) intense activation of the temporal lobes is detected while performing cognitive tasks. Moreover, a correlation between the level of education and the level of using the temporal lobes was found. On the other hand, among subjects who were older than sixty-five, intense activity was detected at the frontal lobes while performing thinking tasks, and, once more, a correlation between the level of usage of the frontal lobes and the level of education was found.
Brain Seasonality
Our brain operates according to cycles of seasonality on different time axes: throughout the day, throughout the month, and throughout the years (periods of life). The biochemical profile that characterizes this seasonality undergoes changes. Every period has its own “fingerprints,” in the sense of the cocktail of neurotransmitters and hormones that create the internal climate, under the auspices of which our brain functions. In each season, our brain is “prone” to producing performances that reflect its internal climate.
Sometimes this weather is capricious and shakes the ship of our brain aggressively. The traditional example of such a situation is premenstrual syndrome. Sometimes its impact is moderate and gradual, as a slow change that takes place throughout all periods of life.
The basic temperament of people seems to derive mostly from the activity profile of the neurotransmitters and their receptors in the various brain pathways and the structure aspect—the communication interface (wiring) between various brain areas.
Familiarity with brain seasonality and our place in it will enable us to assess our advantages and disadvantages at a given time. We should not consider the inner climate as the essence of it all. Our insights related to it might help in creating conscious climate changes, up to a point. Nevertheless, in other senses, we are like biochemical marionettes with a maneuvering range that derives from being aware of our state and from our ability to react out of “understanding the position” in which we live.
At all stages of our life, we will make better decisions if we have a clearer picture of the season that affects our brain, which will grant us better control of our destiny.
Vivaldi—the Brain Version
We can refer to four seasons of the brain—f
our periods in our mental and emotional life: infancy and childhood, adolescence and adulthood, the “transitional season” of the brain during middle age, and old age.
The various seasons of the brain are characterized by structural, biochemical, and functional changes.
A seemingly natural comparison of spring to youth and winter to old age is not obvious, since threads of spring are woven in old age and threads of winter and fall are woven in adolescence as well.
Brain seasons are daily and monthly and match different periods in life. At least these three layers of time exist in all of the brain seasons among men and women, according to the specific resolution of time that we chose to look at.
Time Changes—Seasons of the Brain
Changes are a matter of routine in our brain, and this is also true for the cycle of our soul life throughout day and night.
Our brain changes also with respects to its approach to information processing, which is carried out according to a daily and monthly cycle and throughout all the seasons of our life.
The daily fluctuation is reversible and cyclic; fluctuation throughout life is less reversible.
Change of Brain Seasons Throughout the Day
As aforementioned, brain seasons also exist according to a twenty-four-hour cycle. The pendulum of hemispheric dominance (dominance in the sense of concentration of the lion’s share of brain processing, and not in the sense of “autocracy” of one of the hemispheres) passes from one hemisphere to the other throughout the day.
At any given time, there is a mix of brain activity that is divided between the hemispheres in accordance with the circumstances. At night, when the external sensory input is very limited, it seems that the dominance pattern moves more abruptly between the two hemispheres, and the mix is more prone to reflecting dominance of either the right hemisphere or the left one (in accordance with the stages and times of sleep).
Certain suppositions that are mentioned in this book do not comply with the basic requirements of statistics, since they are based on self-introspection and the sample includes only one subject. Such is the supposition regarding the nightly cycle of the mood pendulum and emotional thinking. Although it is all about self-observation—“individual domain”—it might also be valid with respect to others (“public domain”). According to this observation, at about three a.m., “right dominance” takes place—which induces a realistic point of view that lacks a comforting angle regarding reality. This feeling lasts until about four a.m., the hour of truth of reality testing, just before the comforting morning dew, which takes the form of a neurotransmitters’ potion formed under the auspices of “left dominance” and which smoothens the spiky wrinkles of reality and makes sure we are ready to cope with the new day ahead of us.
Chapter 14: How the Brain Deals with the Dimension of Time
Chrono-architecture in the Brain (Synchronism at the Nerves’ Pathways)
We run our life according to external time pacers: the clock, whose clicking dictates the pace of our day, and the calendar, whose dates serve as reference points that outline our conduct. Sometimes we forget that internal clocks are embedded within us, time pacers that are built into our body, and we need to listen to the ticking of their hands no less (and perhaps even more) than we listen to the ticking of external time pacers.
“The internal clock” of each and every one of us dictates the rhythms of our life, but it seems that most of us underestimate the speed of its hands.
The Greenwich point of our brain outlines the perceptional reference point with regard to the experience of time (in a humoristic tone, some might say that among married men, this point is often distorted, since, contrary to their perception, they do not live longer; they just see it as a longer time).
The chief candidate to be considered the Greenwich point of the brain, the reference point according to which the “brain time” and a great part of its rhythms are determined, is the cluster of cells in the area called the supra-chiasmatic nucleus (SCN), which is located above the crisscross of optic nerves at the bottom of the frontal lobe. The main role of timing the circadian cycle is preserved for the SCN. In order to calibrate many of our body’s rhythms, there are some elements that assist the SCN: the paraventricular nucleus (PVN) at the hypothalamus, the ganglion of the sympathetic system at the top cervical area, and the pineal gland, which is located at the core of the brain.
The SCN has a central role in timing body rhythms—daily, monthly and annually—which affect a variety of physiological derivatives and, particularly, the cycle of sleep–wakefulness.
Our brain operates as a sort of shutter for the framework of perceptual time through which we sample the world.
The hardware we are equipped with—the senses and the perception and processing system in the brain—includes a “time shutter.” The impressions our senses mine from the mine of world phenomena are sampled in typical windows of time.
The time resolution of the brain is within the meso range (the middle range between the micro level, which represents time periods that are shorter from those that are “natural” for our consciousness, and the macro level, which represents time periods that are longer than those that are “natural” for our consciousness). Daily world manifestations, as perceived by our senses, exist in accordance with the rhythms of the level of time resolution within the meso range. It is difficult for us to perceive time frames that deviate from the limits of our natural time shutter, such as macro time frames (whose duration is assessed as millions and billions of years) or, at the other end of time amplitude, time frames at the micro level (whose duration is assessed in fractions of a second).
Final forever: A final thought has difficulty in perceiving infinity, so our consciousness has a built-in difficulty in understanding infinite terms. It seems that our consciousness has a “sense of time” that matches human’s life expectancy, and not much more beyond it. Our “sense of time” is imperfect, in the sense of evaluating the meaning of long periods of time such as millions or billions of years. It might be the source of our perceptional difficulty of assessing changes along such durations, which are common in descriptions of phenomena related to evolution, geology, and cosmology.
In a paraphrase of a similar claim, we might say that from each point on the face of the earth we are equally remote from infinity. We are ephemeral, and our distance from infinity is infinite.
Time resolution is different with respect to inputs that derive from different senses. Thus, for example, with respect to a visual input, the frames of a film are perceived as successive when they are projected at a rate of twenty-four frames per second and higher, but at a decreased frequency they might be perceived as non successive. These are the “whiteness interruptions” in the early days of cinema. We are not equipped to perceive changes in reality manifestations that occur in time periods of milli (thousandth), micro (millionth), nano (billionth), or pico (trillionth) of a second.
In 1983, brain researchers from the Max Planck Society reported a case of a woman who suffered from movement-perception impairment (called “akinetopsia” in brain research jargon). The patient, referred to as LM, reported that she experienced visual input as discontinuous and nonsuccessive—a sort of a serial collection of separate impressions perceived alternately. She said that when she pours tea from a jar to a cup, the course of the liquid downward is perceived in her brain as a sequence of “frozen situations,” which made it difficult for her to assess the amount she pours, and the cup often overflows.[46] This description is a visual picture, which is a sort of mirror image to the successive frames of modern films and a (sad) regression in time to the early days of cinema. The woman who suffered from this disorder was afraid to cross the street, since she perceived the cars as being far away from her and all of the sudden very close to her. Her impaired estimation of distance almost always made her feel as if an accident were about to occur. A CT scan of her brain revealed large lesions around the interface between the parietal lobes and the
temporal lobes at both sides of the brain. The injured area in both sides contained the central crest of the temporal lobes, which is in charge of perception of movement.
A material demonstration that is similar to her description can be found in the wonderful work of the Chinese sculptor Tsang Cheung Shing. In Coffee Kiss, tea and coffee, poured from different cups, “freeze in time” and become figures that kiss each other.
“The time areas” that are in charge of chrono-architecture in our brain operate in various speeds.
Similar to the time zones on Earth, different brain areas tend to time performance tasks differently. Some of these areas produce output almost in real time, and other areas are characterized by a delayed reaction and contribute to a later chronological layer of the task.
The human male brain and the human female brain dance to the music produced by similar, but different, drums. This results in different synchronization of life rhythms. Thus, for instance, women, on average, tend to fall asleep earlier than men and wake up a little earlier as well. This difference in sleep–wakefulness timing starts in adolescence and lasts until after middle age.
The Brain Copes with the Dimension of Time
Epicurus, the philosopher, raised an interesting argument. According to him, the reference points of our life are like poles of eternity: the time of our birth ends the sequence of eternity that preceded our existence, and our death starts the sequence of eternity in which we do not exist.