Behind the Scenes of The Brain Show

by Zeev Nitsan

  Looking through a narrow peephole, and from a simplistic point of view, we might be able to claim that the central mediators of signals that compose the Morse code of the emotions in our brain are serotonin, which induces relaxation and peace of mind; dopamine, which initiates expeditions in search of novelty; cortisol, which induces stress and distress; opioid, which induces tranquility; oxytocin, which derives a sense of emotional satisfaction from contact with others; adrenalin and noradrenalin, which add energy, focus, and vitality; and the acetylcholine, which serves as lubrication oil in the wheels of the loom that weaves the threads of our memories.

  And the endorphins, natural painkillers, are similar in their structure and effect to opioids, inducing relaxed tranquility and good mood.

  Each emotion is accompanied by a typical mix of neurotransmitters; for instance, the biochemical fingerprint of emotional distress is a descent in the levels of serotonin, dopamine, and oxytocin and an increase in the level of the stress hormone cortisol.

  The brains of men and women may be different with respect to the mix of neurotransmitters, even in a similar emotional climate. A central component in the “pink cocktail”—estrogen—thus causes an increase in the levels of dopamine and oxytocin.

  The oxytocin inducts a tendency of relating to others and developing intimacy and is considered to be the “drug of closeness,” in women’s brain in particular.

  On the other hand, vasopressin is the main hormone in charge of turning on the lamps lights in the lane to the fellow man in men’s brains and inducing affectionate emotions toward others.

  An increase in the levels of oxytocin and vasopressin takes place in the brain after taking the drug “ecstasy,” which encourages tendency toward “artificial love.” In this sense, it might be seen as the “love drug,” which provides contemporary support to the old insight according to which “love is addictive.”

  DHEA is a spring from which both testosterone and estrogen flow and is considered the Zeus and Hera of hormones.

  Androgens are hormones related to aggressiveness and intense interest in sexual intercourse, and, on the other hand, to reduced empathy toward others among both men and women. The main ones are the testosterones, DHEA, and androstenedione. The level of these hormones is maximal at the age of nineteen among women, and twenty-one among men. In the male body, testosterone is produced at a rate ten times higher than in the female body; thus, its influence is more prominent in average male behavior. The level of androsterone increases during the second and third week of the female period. Women who take birth control pills, which depress the activity of the ovaries and make them discharge fewer androgens, are less susceptible to the effect of androgens on their behavior.

  One of the most familiar effects of the hormonal potion flooding our brain at a given moment is related to attraction between men and women. For example, a study pointed out that, on most days of the month, women prefer a male face characterized by symmetric, round features; during ovulation, they prefer more prominent, manly features that emphasize gender differences, such as a “square” face and prominent jaw.

  The Sunset of Sunrise—The Janus Faces of Drugs

  The issue of using psychoactive drugs is a charged one and requires cautious walking on a rocky lane. (A comic illustration of the complexity is Homer Simpson saying, “I’m too drunk to drive—wait a minute! I mustn’t listen to myself when I’m drunk!”)

  When the ship of our thoughts is carried on the waves of hallucinatory drugs, it is prone to cross the equator of rationality and reach illusionary destinations that do not appear on the maps of logic.

  Should we be afraid of using psychoactive substances to the point that we avoid using them altogether? The answer to that is simple and unequivocal: yes and no. The difficulty is in determining the borderline for the admissibility of psychoactive substances from an external source (admissibility in the sense of nondestructive impact on brain function).

  Our brain knows how to deal with self-produced drugs, but some of the drugs that come from outside of our body might disrupt our brain’s function irreversibly. On the other hand, among these drugs there are some that might better brain performance and improve certain aspects of its function. When we consider using them, we must adapt a selective, realistic approach.

  Throughout history, man has been trying to search the kingdom of psychoactive substances for a panacea—a universal magic medicine, a sort of magic bullet that will hit the core of sadness and desperation and has the power of curing all existing diseases of the soul. Unfortunately, it has not been found yet.

  Psychoactive hallucinogenic substances that are considered psychedelic, such as LSD and magic mushrooms, might be used as therapeutic substances. There have been attempts to combine them as part of therapy in cases where patients do not respond to conventional medical treatment in cases of chronic depression, post-traumatic stress syndrome, and drug and alcohol dependency.

  There are “legal drugs” that are socially accepted nowadays and might have a good effect on brain function. Drinking coffee, for example, was found to reduce the risk of dementia, and it seems that nicotine itself, isolated from other chemical substances that are usually attached to it in tobacco and make the smoking more damaging than beneficial, might have a good effect on thinking functions. In this context, a significantly lower frequency of Parkinson’s disease was found among smokers. The reduced risk is usually ascribed to the energizing impact of nicotine on dopamine-producing brain cells. In light of the above, researchers are considering the option of prescribing isolated nicotine, not attainable by smoking.

  A weighty argument of those who object to non-therapeutic usage of psychoactive substances is often presented as a question of whether we were meant to turn into “zombies” and sacrifice our precious, ephemeral sobriety for the sake of momentary delight.

  The functions of our soul are vulnerable to the impact of external drugs: our conscience might melt in alcohol; our short-term memory might be damaged as a result of lasting use of marijuana; LSD might resurrect hallucinations performed on the stage of our consciousness, accompanied by dazzling pyrotechnics, even years after taking it.

  The peak of the mountain of “artificial happiness” is white, and its slopes are dangerous: the brain profile of a person who uses cocaine is similar to the brain profile of a person who experiences divine happiness, but the re-encounter with reality, after the dream of happiness evaporates, might be cruel and lethal. Among other things, cocaine increases the risk of stroke.

  Hallucinogenic substances might produce, in the halls of our brain, an illusion show, which is actually a synthetic scenario that does not match reality. In this spirit, people say jokingly that one of the ways of knowing that you are drunk is when you lose an argument with standstill objects. A person who takes a psychoactive drug is present in his body, but his spirit sails on the sea of imagination. Under certain circumstances, the lack of compatibility might cause a person to make decisions that are valid in his fictional world but can risk his life in reality. There are psychoactive substances that initialize apoptosis (from the Greek word for exfoliation) among brain cells—a process of death that sends cells to the gallows.

  There is always the risk of getting caught in the spider’s web of an addictive substance. Addiction causes structural changes in the brain, some of which remain for life. The main features of addiction are obsessive craving for the addictive source; developing tolerance, which requires higher levels of stimulation in order to experience a sense of satisfaction; and difficulties in making do without the addictive substance.

  Dopamine is sprayed from the ends of dopaminergic nerves in response to an achievement that involves effort. Addictive substances provide the “reward” by infusing dopamine that we achieve in an effortless manner.

  The wave of dopamine that stimulates excitement shapes and reinforces the nerve network that encodes the activity that caused its creation. A feedback mechanism is thus created, which reinforces t
he link between dopamine and the addictive behavior. Sometimes, in order to retain the fragile balance between the concentrations of compounds of neurotransmitters, which constantly change, our brain performs “initiated adaptive changes” with respect to the concentrations of these substances. For instance, when a substance like cocaine meets our brain and increases the concentrations of dopamine at once, especially at the structures of “the cycle of pleasure and reward,” our brain, as a means of creating balance, reduces self-production of dopamine. Brain imaging through PET scans shows that, in the brain of a person who uses cocaine frequently, there is a decrease in the basic amount of dopamine when the person is not under the influence of the drug. Such a decrease, as in a vicious circle, increases the craving for cocaine.

  Chapter 7: Memory Functions

  Memory Classification in the Mirror of Time

  A conventional classification of memory is done according to information preservation on the time axis.

  At first, reality manifestations meet our sensory organs, and the changes in these organs resulting from this encounter are called “sensory memory” or “very-short-term memory.” These are the perception impressions, as they are perceived by the sensory organs and the primal input areas in the cortex, at their raw, initial state, prior to brain processing.

  These changes are like the pattern of a circle perimeter that expands when a drop of water hits the surface of the puddle.

  The initial visual input is called “iconic memory.” Its “life span” is long enough so that a modern film, which is projected at a speed of more than twenty-five pictures per second, will be seen as a continuum. The previous picture still “remains in the eye” when the next one is projected. Old movies from the “silent era,” however, which are projected at their original speed of fifteen pictures per second, seem segmented, since the icon of each of the pictures starts to evaporate before the next picture is shown. The retention of primary auditory input is called “echoic memory.” The retention of the liveliness of the sound beyond its actual occurrence enables one syllable to echo in our mind until we hear the next one, and we recognize the meaning of the auditory input by means of the context.

  The same is true for music. “Echoic memory” enables the retention of one sound until the next one appears, and the interface between sounds that touch each other’s heel makes music come into being.

  “Present-Momentary Memory” or “Working Memory”

  The second meeting point between the sensory impressions and the brain along the time axis generates the short-term memory. There is controversy about the borders of this type of memory in the kingdom of time, but most experts claim that its range is between several seconds to thirty seconds.

  Those who believe in the motto “business before pleasure” might prefer the term “working memory” as the term describing short-term memory, since it enables us to make lightning-fast decisions regarding pieces of information that are piled up on the desk of consciousness, subject to time and capacity restrictions—which will be further processed and doomed to oblivion.

  Working Memory Characteristics

  Our working memory preserves perception impressions on the screen of consciousness once they are perceived and for a short time afterward and, by doing so, enables us to process information consciously. This type of memory is formed and exists primarily at the frontal part of the frontal lobes (the prefrontal area). A secondary contribution to its formation derives from activity at the parietal lobes and the brain area called anterior cingulate gyrus.

  The prefrontal areas serve as a sort of working desk on which we pile the perception impressions so that we can manipulate them mentally and process them. In this sense, these areas serve both as a storage place and a processing workshop.

  The short-term memory has a passive aspect—the perceptional recording—and an active aspect that includes thinking about the input in a conscious manner or memorizing the input in order to retain it in our consciousness. The active aspect represents voluntary involvement “from within” regarding contents that mostly derive from the outside.

  The Outlines of Real-Time Memory Capacity

  Studies have shown that the capacity of working memory (the channel of existence of momentary consciousness) is seven items of general verbal information on average. The average capacity of spatial-visual information is about four items of information. In other words, we retain in our real-time memory seven “general information” items, and when it comes to spatial information (the location of objects in space), the average capacity is about four pieces of information. The volume of our real-time consciousness changes according to the type of information retained in it.

  Two central aspects of the working memory are the spatial-visual memory and the verbal-tonal memory, which is also called the “phonological loop.”

  In our brain we retain names of figures in a resonant phonological loop (the “phonological loop”) with a two-second life expectancy. The longer the name of the figure is, in the language our brain thinks in, the shorter the sequence of numbers recalled by our brain will be. A long name of a figure extends the encoding time necessary for its preservation and leaves us less time to encode the next numbers in the two-second window of time before the expiration of the phonological loop. A study showed that Chinese speakers of the Cantonese dialect are able to recall a longer sequence of numbers compared to speakers of other languages, since they blessed with names of figures in their language that are especially short and catchy.

  This is another example of the fact that the language in which our brain “speaks” casts its shadow over “pure” thinking functions as well.

  In the spirit of time, some may compare the transition of information from the working memory to the long-term memory to the transition of information from the computer screen to the hard disc.

  The vitality of our working memory in terms of verbal information is extremely frail. In most cases, it exists in the frontal lobes for several seconds. The preservation of its vitality is enabled due to the bioelectrical resonance induced among the neurons. When the resonance is over, the information fades away at once. In love terms, some compare working memory to a one-night-stand—when the future of the relationship is vague and uncertain. On the contrary, our long-term memory bases its status on structural changes that create consistent footprints and may be compared in the same spirit to a life-long marriage (“Catholic memory”).

  Working Memory and the Screen of the Shadow Memory

  People who are well familiar with the secrets of fairytales know that one can identify a witch or a demon on a sunny day, since they do not cast a shadow. On the other hand, in museums of science, there is popular exhibition called “shadow memory.” The exhibit is formed due to a flash of light projected on the visitors, and their shadow, which is projected on the screen, remains on it even after they draw away from it. The shadow lives on its own and gradually fades out. The magic derives from the fact that the screen is made of phosphorescent substance, which preserves the “shadow memory” and creates the delay in its fading out. Similarly, our working memory, as with the phosphorescent screen, preserves the footprints of sensory input for a short period of time after its actual disappearance.

  According to a common classification, the long-term memory (LTM) includes recent and remote memory.

  The LTM is a “Methuselah memory”—in the sense that it has long life expectancy.

  The biological substrate of the LTM—its material footprints—are the structural changes at the junctions of interface between the neurons (the synapses) involved in memory preservation.

  LTM is essential to “deep-perspective” thoughts, since the narrow window of time during which working memory exists does not provide enough time for building a high tower of thoughts.

  For instance, a tomato is perceived in our sensory memory as a round, red entity with a smooth texture. In order to conceptualize it as a tomato, it is essential that this information meets our LT
M, which will contribute the necessary information and complete the task of identification.

  The volume of the LTM, in the sense of the volume of pieces of information stored in the brain of an average human being, was estimated by researchers as five hundred times bigger than the information included in all volumes of the Britannica Encyclopedia.

  The Weight of Memory

  A short story demonstrates the heavy weight of the LTM. Two monks were about to cross a stormy river, and, along the bank, they met a beautiful girl who begged them to help her cross the river. One of the monks took it upon himself. He carried the girl on his back and crossed the stormy river with her and with his friend, the monk. On the other side of the river, he put down the girl, and she thanked him and went away. The monks continued the journey to the monastery quietly. Twenty years later, the monk said to his friend, “I will never forget that twenty years ago, on our way to the monastery, you broke the monk’s vow and touched a woman’s body while carrying her on your back to the other side of the river.” The other monk answered, “I carried the girl on my back for a few minutes and forgot all about her afterward. You have been carrying her in your memory for the last twenty years and never forgot her. The weight of your memory is much heavier than her physical weight.”

  Memory Classification According to Their Interface with Consciousness

  Many brain researchers support the assumptions that most memory processes are formed and preserved out of consciousness’s jurisdiction. These memories are described as implicit or concealed.

  In many cases the impressions of our experiences affect our behavior and the principles of our faith without being accessible to consciousness. The lack of accessibility to conscious recollection does not mean a person does not know. In this case, his knowledge is implicit or concealed. Moreover, it does not mean his behavior will not be affected by that knowledge that is owned by his brain. Such “dumb knowledge,” which is present but “does not speak itself” in the bustle of the stream of consciousness, is still heard. Implicit memory impressions are involved in information processing in the brain routinely and affect our behavior at any given moment, even if they do not “float” on the surface of consciousness while they exist in the layers of unconsciousness or preconsciousness. The penetration of memory into the domains of conscious experience is not essential to its effect on our behavior.