Neuroscience, Neuropsychiatry, Neurology


Socialization, Self-Image, Sex, Emotion

Information Transfer, The Corpus Callosum

R. Gabriel Joseph, Ph.D.

From: The Right Brain & the Unconscious (Plenum).

If we were to remove the top of someone's skull and look straight down we would discover that the human brain is divided into two halves by a large fissure called the interhemispheric fissure. These two halves form the right and left brains or rather, cerebral hemispheres. In other words, half a brain (or cerebrum) is a hemi-sphere.

If we were to squeeze our fingers down into this fissure our progress would soon be interrupted by a large rope of nerve fibers which interconnect the two brain halves. This great bundle of fibers is called the Corpus Callosum.

The nerve fibers, which make up the Corpus Callosum, acts as a passage way via which a portion of information from one half of the brain may travel and be transferred to the other. It is in this manner that the two halves of the brains are able partly to communicate.

The only other manner in which a very limited amount of information can be shared between them is via a tiny tract of nerve fibers called the anterior commissure. There is no other "psychic corridor" and any other information exchange occurs only to a minimal extent via very indirect and circuitous routes through the very ancient limbic system and brainstem.



Sometimes information that is transferred from one half of the brain is miscommunicated and misinterpreted 1-2. It is not unlike the game of "telephone" sometimes played by children in school in which a single sentence is whispered from student to student becoming distorted along the way. By the time the message has been relayed to the last student it usually has undergone a complete transformation from the original.

The same thing sometimes happens when information has to be relayed and transferred from one half of the brain to the other. Something gets lost and distorted in the process. Moreover, since the two halves of the brain speak different languages (the right being emotional, visual-spatial, geometric and tactual, the left temporal- sequential, analytical and linguistic), misinterpretation is made even more likely because of the need for interpretation. The two brains do not share a common language.


Some information is never even transferred. This is because each half of the brain is concerned with, perceives, analyzes, and memorizes different types of information. Just as an eye will never hear and the ear will never see; the two halves of the brain cannot perceive information they are not specialized to receive. The transfer of certain types of information between the two halves of the brain thus does not take place as it cannot be perceived or recognized by each half's counterpart. Insofar as each are concerned, certain types of information do not exist.

The ability to understand speech is localized within the left half of the brain for most, whereas the capacity to recognize musical melodies is localized in the right half of the brain. The left brain has difficulty perceiving melody and is partially deaf to music, the right does not understand most aspects of speech and is partially deaf to words and sentences. Even if you yell your words or sing real loud these two halves of the brain will hear noise and garbled sounds and will misinterpret the information they receive. They can only see and hear what they are capable of seeing and hearing.


Since memories, perceptions and capacities are selectively represented in one versus the other half of the brain, the two brain halves may reach different and conflicting conclusions about what ostensibly seems to be the same piece of information. This is because each half of the brain is attending to different aspects of what is experienced.

When listening to music, the left brain may attend to the rhythm (i.e. temporal sequences) and words, and the right hemisphere to the melody and emotion being conveyed. Similarly, when talking to a friend, loved one, or salesman, the right hemisphere may attend to the way things are being said, and the left brain may attend only to what is being said. Two different messages may be perceived.

For instance, a husband may tell his wife that he is going to be working late. Her left brain hears that he is going to be "working late" and accepts that on face value. Her right hemisphere, however, hears the melody of his voice, notes the changes in his face and body language as he talks and decides that he is up to something that does not involve work. How she reacts will in turn depend upon which half of her brain prevails as well as on her past experience with her husband and his late night sojourns. In any case, she is in conflict.

While listening to a politician, the left brain may hear, process and become convinced by the words he uses, his promises, and the facts he uses to back up his statements. In contrast, the right hemisphere might detect, via the analysis of tone of voice, body language and facial expression, that the man is insincere and a liar. If the listener fails to employ or utilize the impressions of the right hemisphere and instead relies only on the impressions made on the left half of the brain, then he may be fooled and cast his vote in a foolish manner.

Of course the converse also occurs. Although the politician's insincerity may not be evident his ridiculous promises set off alarm bells in a voters left brain. If the politician is truly effective in swaying the voter's right hemisphere by speaking to his "heart" and appealing to his emotions, then ridiculous promises or not he may end up with the vote.


The two halves may not only perceive things differently but have different memories triggered in response to those perceptions. Emotions, tactile sensations, the location of our car keys, the melody of a certain song, and even the appearance of someone's face are stored in the memory banks of the right hemisphere. Words, sentences, appointments, the name of our dentist, the title of a book, stock quotes, and mathematical formulas are stored in the left brain 3-11.

Based on the differential manner in which a single event may be perceived by the right versus left brain as well as the different memories which may be triggered, each brain may then act in an oppositional manner, one half attempting to do or believing one thing, the other half attempting to accomplish (or believing) something entirely different. When this occurs the person may feel in conflict, confused, mistrustful or even paralyzed by indecisiveness, since certain memories cannot always be shared or transferred from one brain half to the other.

However, the two halves of the brain may also work in harmony. For example, you receive a phone call and immediately recognize by the sound of the voice that it is your dentist (right hemisphere). You remember his name (left brain), his face (right hemisphere), what time your appointment is tomorrow (left brain), the terrible music he plays in the waiting area (right hemisphere), how much it is going to cost (left brain) and how much you do not want to go (right hemisphere).

In some cases memories can be triggered which are enormously traumatic on an emotional level. Still the memory and all its attendant emotions may remain confined to the right hemisphere due to the differential organization of the brain. This is particularly likely if the emotional experience occurred during early childhood. However, adults suffer traumas too.

When Carol was a little girl she was molested on several occasions by her uncle. The first time she was nearly 4 years old and had been sitting next to her uncle on the couch when he began to stroke and run his fingers through her hair. He continued this action while he cajoled and intimidated her into performing fellatio. He did this to her on ten or more occasions over a one year time period until he moved away. Somehow she managed to forget all about this until many years later while in college.

She was in bed with her boyfriend and they had just finished making love when he began to stroke and run his fingers through her hair. All at once she began to panic, became quite hysterical, and started crying and trying to strike her boyfriend. Then grabbing up her clothes and quickly getting dressed, ran from his apartment.

For the next several weeks she refused to talk to him, hung up when he called her and began to feel an overwhelming aversion toward men. She sought counseling, but to no avail.

It was only a year later while watching a movie that the entire memory of what had happened to her, so many years before, unraveled. In the movie a man walked into a crying girl's bedroom and while trying to soothe her began to brush and run his fingers through her hair. Immediately Carol began to feel angry and upset, and then she remembered. The forgotten images began to fill her mind.

Essentially, the memory of what her uncle had done had been stored in the memory banks of her right hemisphere and had been forgotten. Years later, when her boyfriend began to stroke her hair after having sex, the association between sex and having her hair fondled was reactivated. The right hemisphere then began recalling the visual and emotional images of what had happened and became terribly upset.

Her left brain, however, having little linguistic memory of the tactual, sexual act and its associated emotions, had "no idea" as to why she was behaving in this manner. Nevertheless, her right hemisphere prevailed and she ran away in hysterics.

It was only a year later that the left brain was clued in to what had triggered her hysterical reaction. When both the right and left brain observed the man on TV brush and fondle the little girl's hair, Carol's right hemisphere became upset and the images of what had happened to her spilled forth. Looking at the movie and feeling the revulsion the left brain suddenly was given a tremendous amount of information as to what was bothering her and was then offered access to the horror that had so long been locked away seemingly forgotten. Transfer was made possible because they were both observing the same event and feeling the same feeling, upset.

Indeed, I have frequently had patients tell me that long forgotten memories of incest, molestations and other traumatic events from childhood have been triggered by similar seemingly innocuous occurrences. They may be watching children play, putting their own kids to bed, becoming angry when they have broken something, or merely overhear a child saying something innocent in another room when suddenly a long suppressed memory unfolds before their eyes. Essentially the memory is being regurgitated by the right, and the left brain cued by the emotional response coupled with the scene being observed, gains access to what had been a well kept secret of the right half of the brain.


OVER RELIANCE ON THE LEFT BRAIN. In many instances, particularly those involving social and emotional events, what occurs in the right half of the brain may never be transferred or even recognized by the conscious system of the left half of the cerebrum. That is, the left brain may refuse to relinquish control over behavior and may ignore the perceptions, protests and feelings of the right 12-16.

A persons right hemisphere might become aware of a potential problem in a relationship and become concerned, upset or alarmed. If the mental system of the left brain refuses or is unable to gain access to this information, then the person might feel upset and consciously not know why.

This tendency to sometimes over rely on the left half of the cerebrum is unfortunate as the left brain is very concrete and sometimes has difficulty fully appreciating the talents of the right. Some left brains, however, pride themselves on being logical and rational and in control. Unfortunately, this attitude creates many unnecessary difficulties. If the left brain maintains functional dominance at all times and relegates the right hemisphere to second class status, the person may be put at tremendous disadvantage since the right hemisphere is so emotionally and socially astute.


The right hemisphere is able to decipher a variety of interpersonal cues so as to determine sincerity, dishonesty, sarcasm, love, compassion, purposeful attempts to mislead, as well as deduce what is incongruous and implausible information. The right hemisphere also has a better sense of humor 17. The right hemisphere, however, can also be fooled by a good actor. Nevertheless, it is for these and related reasons that it is often considered the more intuitive half of the cerebrum.

Unfortunately, some left brains don't believe in "intuition" and are quick to disavow "gut feelings," "warning signs," "red flags," and "alarm bells" when interacting with others. Some left brains prefer to rely on "logic," not "emotion". When this occurs disastrous consequences sometimes follow.

Take for example a young couple, Lenny and Lucy who have dated a few times and who go to a party. Lenny is highly attracted to Lucy and is very hopeful that something serious may develop. Lenny, however, having learned rejection as a child strongly believes that feelings are dangerous and should be controlled. As a successful engineer he has also long prided himself on his command of logic, rational thinking, and sober reflection. Hence, although he really likes Lucy, he has not admitted to himself how strongly he feels. He has kept his feelings in check (i.e. suppressed) since they make him very uncomfortable. That is, his desires coupled with his fears give rise to feelings of discomfort which his left brain prefers not to deal with.

These emotions remain for the most part confined to the right hemisphere which his left brain tries to ignore. Thus, he is not entirely conscious of these feelings and his desires and has not verbally expressed them. From a left brain perspective he is merely taking Lucy out to enjoy her company and because he likes talking to her. However, his right hemisphere is hoping for a serious relationship to develop.

Once at the party he begins to notice that Lucy repeatedly glances at a particular man (Jesse). There is something about the way she is looking at him that slightly bothers Lenny (his right hemisphere); although he (i.e., his left brain) is not sure why. Later he sees her talking with Jesse, and although Lenny can make out little more than the tone and melody of her voice, this and the manner in which she is gesturing and smiling makes him (i.e. his right hemisphere) feel peculiar, particularly in that she again has an odd look to her face.

Near the end of the evening he sees Lucy write something on a piece of paper as she and Jesse talk. She hands it to him and they exchange smiles.

On their way home, Lenny, feeling odd and uncomfortable about what he has observed between Jesse and she, feels compelled (by his right hemisphere) to ask Lucy, "What was going on?" She laughs, calls him "silly" and tells him that she and Jesse have a mutual friend, a girl friend of hers whom he has not seen in a long time.

"Then what did you write on that paper?" Lenny asks, still feeling vaguely troubled. "Her phone number" Lucy laughs. Lenny nods his head. "That makes sense," he (his left brain) decides. And indeed it is logical and a rational response. Yet something in her tone of voice bothers him (his right hemisphere).

Arriving at her home, Lucy says she is terribly tired and does not invite him in as she had on their previous outing. She yawns and looks exhausted. Lenny is sent on his way.

However, Lenny, although satisfied with the reasonableness of her explanation still feels uncomfortable. He argues with himself, rationalizes her actions, and again shrugs it off.

What is going on in Lenny's mind? Lenny's right hemisphere, having attended to her facial expression, body posture, movements, tone of voice, and so on, is fairly convinced that he may have lost his girl friend and that she gave Jesse her phone number. Insofar as his right hemisphere is concerned, Lucy is lying and trying to deceive him --perhaps to spare his feelings. The right hemisphere is upset and is justly aware of the fact that he should chalk this one up and not damage his ego by calling her again.

Lenny attempts to suppress these irrational, non-logical thoughts, feelings and impressions. They are countered by Lenny's left brain and its perception and rationalization regarding what occurred. All his left brain noticed was that she looked at and talked to Jesse. His left brain heard her explanations, and to his left brain they sounded perfectly rational and reasonable. The left brain, having great difficulty discerning social-emotional nuances, takes Lucy at her word rather than her tone.

The left and right hemisphere are in conflict. Lenny, however, manages to resist consciously acknowledging (linguistically) what he is unconsciously aware of and understands non-linguistically. He represses what his right hemisphere is fully aware of. He hides these implications from himself. He is self -deceived. His left brain has fooled itself and has failed to take right hemisphere feelings into account (as is his tendency anyway). He may also be influenced and sensitized by a past rejection which still affects him.

A few days later, although still feeling odd and a little insecure, he calls and asks Lucy out for the coming weekend. She, however, tells him "no," that she is planning on "washing her hair" that day, and thus makes a fool out of both halves of Lenny's brain.

Hanging up, Lenny's left hemisphere, although still wanting to take her at her word is now overwhelmed by the right. "Don't ever call her again!" it cries in it's own unique language. But Lenny's left brain, not wanting to admit to what he is unconsciously aware of, is still tempted. A week later he calls again and Jesse answers her phone.

Although having two brains which perform so many different functions confers enormous advantages, unfortunately it also predisposes us to develop intra-psychic conflicts and to sometimes ignore warning signs and alarm bells when interacting with others. This may be particularly treacherous when dealing with members of the opposite sex. Often the left fails to attend to or acknowledge what the right hemisphere is fully aware of. However, sometimes the left brain is actively prevented from gaining access to this information.


It is sometimes very difficult for the two halves of the brain to cooperate and to exchange thoughts, feelings or ideas. As a consequence of lateralized (right vs left) specialization, certain types of information cannot be detected much less recognized by the opposite hemisphere. Even information which is transferred from one half of the brain to the other may be subject to interpretation and misinterpretation.

In addition, one brain half can be prevented from knowing what is occurring in the opposite half due to the inhibiting and suppressive actions initiated by, for example, the Frontal Lobes. The Frontal Lobes are in essence the Senior Executive of the brain, ego and personality 18. They control behavior and attentional and information processing throughout the brain via inhibition, suppression and censorship. If a persons frontal lobes were severely damaged, he might say whatever pops into his head or act on any impulse without thinking first and without concern for the consequences.

Since there are two frontal lobes (interlinked via the corpus callosum), one in the right and one in the left, they are able to assist greatly in determining what information is processed within each half of the brain and what may be transferred between the hemispheres as well. They may act to prevent information from crossing over this "psychic corridor," the corpus callosum via inhibition. Thus it could be said that they engage in censorship and stand guard on either side of the callosum so as to determine what may pass.

Interestingly, whereas the left frontal lobe maintains inhibitory control over the left brain, the right frontal lobe is able to exert inhibitory influences on what is processed in either half of the brain. Indeed, the entire right hemisphere appears to be dominant in regard to attention and arousal 18-22.


It is important to emphasize that a considerable degree of cooperative interaction occurs between the mental systems of the right and left halves of the brain. Many functions in fact require their dual and simultaneous interaction.

To read a book I must keep my place on the page (in visual-space) so that my eyes do not wonder haphazardly from line to line (right hemisphere function). Simultaneously I must read and decipher the linguistic symbols and letters which make of the words and sentences and keep track of their temporal-sequential, grammatical order (left brain function). Moreover, when I decide to go back to my book, I must remember where in my house I left it (right hemisphere). If I ask someone where it might be, I must recall its title (left brain).

To make music also requires the dual interaction of the two brain halves. The left provides rhythm (temporal sequences) and the right provides the melody. Similarly, when we dream, the visual, emotional, hallucinatory qualities are provided by the right hemisphere, whereas the left brain may provide the accompanying verbal commentary or dialogue.

Indeed, optimal functioning as a human being requires full and harmonious use of both the right and left halves of the cerebrum. Moreover, there is also considerable overlap in functional representation. Some abilities are maintained in both halves of the brain.


The mind and brain are intimately linked, for if you damage the brain you damage the mind. That we posses two brains and that each brain has a mind of its own should not at all be surprising.

If indeed language is highly interwoven and related to consciousness then it seems quite reasonable to assume that the conscious mind is clearly linked to the functional integrity of the left half of the brain among most people.

In this regard what so many authors have referred to as the subconscious and unconscious appears to be more clearly associated with activity occurring in the right half of the brain. However, the right hemisphere is also associated with so much more.

The right hemisphere predominates in the perception and identification of environmental and non-verbal sounds, the maintenance of the body image, the comprehension of melodic, and emotional speech, as well as the perception of most aspects of musical stimuli. The right hemisphere is also dominant regarding the analysis of geometric and visual-space, including depth perception, position, distance, movement, and stereopsis -capacities essential for stalking game or playing football, tennis, or basketball.

Hence, it is the right hemisphere which allows one to throw and catch a football with accuracy, whereas it is the left brain which keeps score. The right hemisphere allows us to dance the night away while the left brain worries about the time. The right hemisphere produces seemingly bizarre sometimes highly emotional dream imagery, whereas the left brain is unable to remember the dream in the morning. The right hemisphere allows us to drive from point A to point B while our "thoughts" are elsewhere. The right hemisphere likes to sing and listen to music, while the left brain keeps the beat and enjoys "talk" radio.

There are thus a myriad of activities at which the right hemisphere excels and in which the left brain plays a minor supporting role (and vice-versa).

Thus the mental activity of the right hemisphere is not something completely hidden or submerged and that defies scrutiny. Right brain activity and unconscious mental activities are not synonymous. The right hemisphere performs so much of its activity naturally and thus seemingly sereptitiously (e.g. such enabling us to put our clothes on without thinking about it, drive a car, run, jump, dance), that it does not draw much conscious attention to it. This situation could also quickly change if the right hemisphere were upset.

Indeed, it is able to perform many of its functions without any assistance from the left brain (other than motor support), although, much of what it engages in, the left brain is able to observe and even comment on. Of course, the left brain misses much as well.

Nevertheless, the right hemisphere provides much information that enables us to navigate through the environment and social relationships in a potentially successful manner. It is this same awareness which allows us to reflect upon our self image and to appreciate the beauty, danger, excitement and intrigue which makes up our environment.

However, from a conscious (left brain) perspective, much of what occurs within the domain of the right is not susceptible to conscious scrutiny or analysis; in part because it is non-linguistic, cannot be labeled or categorized verbally, and is not temporal sequential. In this regard right hemisphere processing can be an unconscious phenomena. It is unconscious because the left brain cannot recognize it verbally and may not know about it until after it has occurred or until after it has lost control and the consequences have been experienced.

Sometimes the left is completely overwhelmed by right hemisphere emotional outbursts, or mental activity such as the visual imagery experienced in the form of a "day dream," which the left then quite passively observes; similar to what occurs while dreaming at night. However, sometimes the left brain simply "blanks out" and pays no attention, or what it observes does not register because it cannot be recognized.

So does this make these right hemisphere mediated events and our associated feelings unconscious? Not necessarily. What seems to originate unconsciously is often amenable to conscious scrutiny and examination. We can talk and write about some of these experiences.

Although non-linguistic and non-conscious, we are capable of becoming fully aware of what is occurring in the right hemisphere. We are aware of birds singing, we can hear a quiver or the emotion in the voice of a friend or lover, we can judge distance when throwing or catching a ball, and we are aware of where our legs and arms are in space when we walk, skip, dance or run; and we can do all these things without thinking about then. If we choose to we can also become consciously-aware of all them as they occurs.

It is just very difficult to put what the right hemisphere experiences into words. However, it is also not always necessary or useful. Instead of thinking, sometimes we need to just feel, experience, and observe without talking about it. If we only talk and think, all this beautiful, intriguing and informative stimuli fades from conscious consideration as we instead focus on single features of the environment or mistake words and labels for reality. If we stop talking for but a few moments and stop our thoughts, then the singing of the birds, the chirping of squirrels, the distant laughter of children will suddenly come to the fore. If we consciously reflect on them, however, we will also know that we were aware of them the whole time.

There are thus a myriad of activities at which the right hemisphere excels and in which the left brain plays a minor supporting role (and vice-versa). However, since so much of what the right hemisphere engages in does not require conscious assistance, it thus seems to be less important or even insignificant, at least insofar as the left brain is concerned. In fact scholars as recently as the 1950's argued that the right hemisphere was more like a well trained automaton and any mental functioning it assisted in was almost completely superfluous and irrelevant.

Moreover, since the left brain controls speech and the right hand, it has long been described by numerous scholars and scientists as the "dominant" half of the brain. Indeed, since the left brain talks and thinks in words and tends to label and categorize linguistically all that it experiences, this aspect of the mind seems to predominate in regard to most psychic interaction as well; that is, it tells itself it is predominate.

Unfortunately, many of us practice a kind of left-brain jingoism and treat the right hemisphere like some third world country. Even our education system stifles right hemisphere development by stressing and rewarding left brain abilities, such as reading, writing, arithmetic. Many right hemisphere capacities such as drawing, painting, sculpting, music, dancing, sports and gymnastics are relegated to recreational status at best; as if having studied algebra for two years while a student would serve most people better twenty years from now than having refined their various non-linguistic skills.

Although right hemisphere capacities are underutilized, ignored, and even suppressed they nevertheless wield enormous influences over our behavior and ability to lead successful, happy, productive lives. Because the two halves of the brain cannot fully communicate and tend to process, store in memory, and recall different aspects of what ostensibly appears to be the same event, considerable conflict between the right and left brain can occur. It is when this happens that the left brain becomes alerted to the possibility of forces which are acting outside its control.

Thus, "out of sight, out of mind" (that is, the mind of the left brain), does not prevent the fermentation of inner chaos and even revolution. The consequences of suppressing or underutilizing the right hemisphere can be disastrous if its feelings and emotions unexpectedly erupt thus greatly affecting the world that both halves of the brain share and occupy. When this occurs the left brain is likely to cry out: "I don't know what came over me," or even "The devil made me do it!" as if sin and Satan were somehow associated with the right hemisphere and the left side of the body.


Probably one of the more important distinctions in the qualitative differences between the right and left cerebral mental systems concerns emotion. As previously indicated there is a considerable body of evidence indicating the right hemisphere is dominant in the expression and perception of visual, facial, and verbal affect , including the ability to make inferences, or determine a person's mood, attitude and intentions via the analysis of posture, facial expression, body language, and vocal melodic and intonational qualities.


Because the right hemisphere is dominant in controlling most aspects of emotion, when damaged a myriad of affective disturbances may result. This includes mania, depression, hysteria, gross social-emotional disinhibition, paranoia, delusions of grandeur, confabulation, denial, neglect, euphoria, childishness, puerility, emotional lability or conversely, complete indifference and apathy 23-28.

Because of its dominance for perceiving faces, patients with damage, as we've seen, may fail to recognize the faces of friends, loved ones, or even their pets. For example, a farmer who had a stroke in the right posterior part of his brain (where facial recognition is subserved) complained that he was having trouble recognizing his wife and could no longer tell his cows apart.

Some patients can become quite emotionally upset when they have these and related perceptual difficulties, particularly in that the right hemisphere also controls emotion. If it is not apparent that they have had a stroke, doctors usually diagnose them as delusional, paranoid, and crazy.

For example, one patient went to the police and claimed his wife had been replaced by an impostor. Although he admitted they looked somewhat alike, he could tell there was something different about her face and voice. He also knew she was an impostor because when she said she loved him, the tone of her voice wasn't right. He was sure she was plotting against him.

There have been many cases where patients have developed what appears to be bizarre psychiatric disturbances when in fact they have suffered a stroke in the right hemisphere. However, if the patient is not also paralyzed (which happens only when certain specific areas of the brain are compromised) most doctors fail to realize that the problem is due to brain damage. There are probably large numbers of such individuals under psychiatric care when their needs would better be served (at least in some cases) by a neurologist, neuropsychologist, or occupational therapist.


Some patients with right hemisphere damage may become delusional, engage in the production of bizarre confabulations and experience a host of somatic disturbances ranging from pain and hysterical body-perceptual distortions, to seizure (epileptic) induced sexual activity and orgasm 29-33. This is because the body and self image is maintained in the right hemisphere.

Other patients have complained of strange physical sensations along the left or both sides of their body such as electric shock like pain, swelling, abnormal tingling, stiffness and the like. However, when they were examined, absolutely no evidence of physical disturbance involving the body was apparent. This is because the altered sensation was an illusion caused by damage to the brain subserving those parts of the body image. Although initially many of these patients were thought to be hysterical or insufferable hypochondriacs, further study indicated right hemisphere tumors, strokes, or epileptic disturbances in the right parietal area where that part of the body image was represented. That is, the body image within the brain became abnormally activated or distorted due to these injuries thus causing these perceptual seemingly hysterical symptoms.

There has also been some suggestion that individuals suffering from anorexia may have damage or some unknown type of disturbance involving the right hemisphere (i.e. the right parietal area where the body map is maintained). Although there is scant evidence in support of this intriguing possibility, it might explain why these young people misperceive their body as fat when it is quite thin.

In any case, body image disturbance, be it neglect, distortion, or even denial of owning a particular body part occurs almost exclusively with right sided brain damage. This is because the parietal area of the right hemisphere is dominant in maintaining the body image and the perception of physical sensation. The left brain can only perceive half a body.

Hence, if that area of the brain where the body image is maintained is damaged, patients (i.e. their left brains) may fail to recognize the left half of their bodies and may misperceive body sensations or fail to perceive them all together. When the brain body map becomes distorted due to damage, perceptions also become distorted when in fact there is nothing wrong with the body. In these instances patients may be misdiagnosed as hysterical.

In fact, the right hemisphere is so heavily involved in emotional and motivational functioning that individuals with right sided lesions show less recovery and are more likely to die as compared to those with left sided destruction. It affects the will to live 23.

LEFT BRAIN EMOTIONAL DISTURBANCES. In contrast, the range of emotional disturbances associated with left cerebral damage seems to be limited to apathy, depression, emotional blunting, and schizophrenia, although euphoria sometimes accompanies receptive aphasia and loss of comprehension.


One of the most fundamental associations with the will to live is reproduction. A species can only survive by reproducing itself and this is accomplished though intimate physical contact, i.e. sex. Bodily sensations and desire for sex, including the urge for sexual bonding, is mediated by the limbic system and right half of the brain.

If the right hemisphere were damaged, not only the will to live but sexual functioning can be severely effected. Indeed, patients with rare forms of right hemisphere damage have sometimes demonstrated or complained of epileptic seizure induced sexual activity and orgasm 34.

One woman with a right hemisphere epileptic seizure disorder would fall to the floor, make pelvic thrusts (as if she were having intercourse) and moan: "Do feels so good" whenever she had an epileptic attack. Other patients with right hemisphere seizures have complained of experiencing painful orgasms when they have an epileptic attack.

Another patient had been arrested 8 times for exposing himself in public. Even his parents complained that he would sometimes walk around the house exposing and grabbing his penis and even on occasion urinate on the floor or on the wall.

Because he claimed he had no recollection of these events he was referred to the VAMC/Yale Seizure unit where I was an intern at the time. Electrodes were placed on his head (to measure brain activity via EEG recordings and to determine if he had epilepsy) and I began to examine him while he laid in bed. Suddenly as we talked his facial expression became blank, his left arm shot out to his side, he made a low moaning sound, and then his hands began playing with the buttons on his pajamas working their way down until he had reached his penis. He then took it in his hand, began squeezing it terribly hard and then let loose with a stream of urine which fortunately just missed me. He was unable to talk or respond to questions and his stare was completely vacant throughout and for a few minutes after the episode. Later, when we looked at his EEG it was apparent that he was having seizures coming out of his right hemisphere.

Hence, he wasn't really exposing himself, he was having an epileptic seizure. His seizure activated those regions of his brain associated with taking hold of his penis. Hence, instead of falling to the floor unconscious or suffering tonic-clonic spasms of the extremities, he would expose himself.

There are numerous studies and observations which indicate that the right hemisphere is more involved in sexual activities than the left. Indeed, EEG electrode studies which have measured the brain's activity during sex have also shown the right hemisphere becomes more active during the sex act and particularly during orgasm 35. Hence, the right hemisphere could be considered the sexier half of the cerebrum.

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DVD 1: Brain Overview

DVD 2: The Left Hemisphere, Brainstem, Midbrain, Thalamus

DVD 3: The Frontal Lobes: Frontal Lobotomy, Memory, Aphasia, Paralysis

DVD 4: The Parietal Lobes: Touch, Body-in-Space, Body Image, Hemi-Neglect, Phantom Limbs,

DVD 5: The Temporal Lobes: Language, Memory, Aphasia, Hallucinations, Face Recognition

DVD 6: The Limbic System: Amygdala, Hippocampus, Hypothalamus, Sex, Emotion, Memory, Stress, PTSD, Hallucinations