Brain Lateralization
By
James Harvey Stout (deceased). This material is now in the public
domain. The complete collection of Mr. Stout's writing is now at
http://stout.mybravenet.com/public_html/h/
>
Jump to the following topics:
- What
is the theory of "brain lateralization?"
- The
two halves ("hemispheres") are joined by the corpus collosum.
- We
can specify the functions of the two hemispheres.
- Ideally,
we develop "lateralization."
- We
tend to use one half more than the other.
- We
tend to distrust or even dislike the non-dominant half.
- We need to
develop both hemispheres.
What
is the theory of "brain lateralization?" Lateralization is the idea
that the two halves of the brain's cerebral cortex -- left and right
-- execute different functions. The lateralization theory --
developed by Nobel-prize-winners Roger Sperry and Robert Ornstein --
helps us to understand our behavior, our personality, our creativity,
and our ability to use the proper mode of thinking when performing
particular tasks. (The cerebral cortex is a part of the brain that
exists only in humans and higher mammals, to manage our sophisticated
intellect.)
The two halves
("hemispheres") are joined by the corpus collosum. This is a bundle
of more than 200 million nerve fibers which transmit data from one
hemisphere to the other so that the two halves can communicate.
Although this nerve connection would seem to be vital, it is severed
in a surgical procedure for some people who have epilepsy. The corpus
collosum is up to 40 percent larger in women than it is in men.
We
can specify the functions of the two hemispheres. (The following
descriptions apply to right-handed people; for left-handed people,
this information is reversed; for example, it is the right hemisphere
which processes analytical thought.)
- The left hemisphere specializes in analytical thought. The
left hemisphere deals with hard facts: abstractions, structure,
discipline and rules, time sequences, mathematics, categorizing,
logic and rationality and deductive reasoning, knowledge, details,
definitions, planning and goals, words (written and spoken and
heard), productivity and efficiency, science and technology,
stability, extraversion, physical activity, and the right side of
the body. The left hemisphere is emphasized in our educational
system and in our society in general, for better or for worse; as
Marshall McLuhan speculated, "The day when bureaucracy becomes
right hemisphere will be utopia."
- The right hemisphere specializes in the "softer" aspects of
life. This includes intuition, feelings and sensitivity, emotions,
daydreaming and visualizing, creativity (including art and music),
color, spatial awareness, first impressions, rhythm, spontaneity
and impulsiveness, the physical senses, risk-taking, flexibility
and variety, learning by experience, relationships, mysticism,
play and sports, introversion, humor, motor skills, the left side
of the body, and a holistic way of perception that recognizes
patterns and similarities and then synthesizes those elements into
new forms.
Ideally, we
develop "lateralization." This is the use of the proper hemisphere
for the task which we are doing. For example, when we are playing a
friendly game of softball (a right-hemisphere activity), we would
lose the essence of the game -- the fun -- if we were overly
apprehensive regarding left-hemisphere matters such as rules and
discipline. And when we are balancing our checkbook (a
left-hemisphere activity), we don't want to be distracted by the
right hemisphere's fascination with creativity and emotions. In every
task, one hemisphere is dominant, but the other hemisphere
participates to some extent; for example, we do have rules during the
softball game, and we can feel happy when we notice that our bills
are not as costly this month. When we understand lateralization, we
become more efficient: we can consciously allow and emphasize the
correct hemisphere, knowing that the sense-oriented right hemisphere
is a better softball player, and the analytical left hemisphere is
better in math. We also benefit from knowing which hemisphere to use
during a particular stage of a task; for example, during
problem-solving, we use the left hemisphere for the
information-gathering stage, but we use the right-hemisphere during
brainstorming and incubation of the ideas.
We tend
to use one half more than the other. During childhood, we develop
"brain dominance" -- the inclination to act and think in the mode of
either the left or right hemisphere. The decision is affected by our
genetics, childhood experiences, and family environment. The
dominance is not total; whether we are "right-brained" or
"left-brained," we permit the other hemisphere to lead occasionally.
We
tend to distrust or even dislike the non-dominant half. If we
generally use our left hemisphere, we might be annoyed by our right
hemisphere as though it were an undisciplined child; contrarily, a
right-hemisphere person might consider his or her left hemisphere to
be a spoil-sport. These same attitudes might be projected onto other
people. For example, if we favor the right hemisphere, but our
co-workers are oriented toward their left hemisphere, we are likely
to judge them as boring and rigid; if we favor the left hemisphere,
we probably view our right-hemisphere co-workers as unreliable and
disorganized. But both types of people can be effective if permitted
to work in their own way, as some employers have discovered.
We need to
develop both hemispheres. This is necessary because, as stated
previously, some tasks require the left hemisphere primarily, and
others predominantly call on the right hemisphere. Our brain
dominance stays the same -- a right-hemisphere person does not change
into a left-hemisphere person -- but we can develop the skills of the
other half, so that that half will be more effective when we need to
use it. We can enhance our non-dominant hemisphere in the following
ways:
- First, we can become more aware of the two modes. What do we
feel when we are in a right-hemisphere mode, and what do we feel
when we are in a left-hemisphere mode? Refer to the lists of tasks
that correspond to each hemisphere, and then note the various
sensations throughout your mind and body while performing the
tasks; while monitoring yourself, be certain that you are using
the proper hemisphere (e.g., the right hemisphere while singing).
We need to be able to sense the differences in order to ascertain
whether we are indeed using our dominant or non-dominant
hemisphere.
- We can become aware of the shift itself. To develop this
perceptiveness, we can do an activity which predominantly calls
for one hemisphere, and then switch to an activity which uses the
other hemisphere, and pay attention to the feeling of transition
in mind and body. When we know what the shift feels like, we can
use this knowledge to verify that a shift has occurred on any
occasion when we want to willfully change hemispheres.
- We can sense the requirement of each task as we perform it. We
can change back-and-forth between hemispheres (by approaching the
job playfully or analytically), to determine whether we feel
better (and are more efficient) when we are in the right or left
hemisphere during this task. For example, when we are
housecleaning, we might think that that is a left-hemisphere task
because we are attending to details and goals; however, because we
are engaged in physical activity, the task is easier if we do it
in the right-hemisphere mode -- relaxing and enjoying our body's
movements and rhythms (and the aesthetics of a clean home). If we
become more sensitive to the differences between the right- and
left-hemisphere modes during our day's activities, we will become
more aware of the needs of each task -- and we will probably be
surprised by the number of tasks which are simpler and more
delightful when we do them from the right hemisphere, with a sense
of play, adventure, spontaneity, and creativity. Or, conversely,
perhaps we will discover that some of our chores need to be
switched from the right to the left hemisphere. If we do not yet
have sensitivity regarding the appropriate use of hemispheres, we
can make a logical estimation by asking ourselves, "How much
analytical thought is required for this task?" In many cases, we
are probably "thinking too much" about a chore that instead
requires imagination and feeling.
- We can acknowledge the presence of the other hemisphere during
any task. For example, while engaging the left hemisphere, we can
be careful not to be too "serious" (and repressive of the right
hemisphere); we may permit some creativity and delight while still
accomplishing our goals. One way to involve the right hemisphere
is to change our attitude from "I have to do this job now" to "I
get to do this job now"; the statement invites the right
hemisphere to cooperate and to find its little unobtrusive
pleasures while we do our work. However, if the right hemisphere
demands more attention than the task allows, we can simply promise
to attend to it later; for example, "When I finish my work, I'll
relax with a snack."
- We can make alterations in our lifestyle. For example, if our
job keeps our left hemisphere engaged (particularly in an
occupation such as accounting or computer repair), we can plan our
free time and home life to utilize the right hemisphere. At work,
we can try to schedule some times (however brief) to let the other
hemisphere express itself; for instance, we can enjoy some
personal conversations during our coffee break at work, instead of
discussing business matters.
- We might become aware of the 90-minute cycles in which the
brain tends toward one hemisphere and then the other. There is no
practical way to schedule our lives around this cycle, but we
might make some concessions to the fact that one 90-period will
allow us a sharper intellect (from the left hemisphere), while the
subsequent 90-minute period will grant us more creativity (from
the right hemisphere). This cycle is probably identical to the
90-minute sleep cycle (i.e., the REM cycle); during sleep, the
brain proceeds through a 90-minute cycle which is characterized by
various levels of brain activity, with REM dreams commencing at
the same point in each cycle.
- We can notice the frustration and exhaustion which occur when
we use the improper hemisphere for a task; perhaps we habitually
use the same hemisphere for virtually everything we do. For
example, for some people, sex is a left-hemisphere activity
because they are concerned with performance, goals (such as
orgasms), size of body parts, and duration of time. The result can
be impotence in the man, and frigidity in the woman. One approach
in sex therapy is to teach the people to relax and enjoy, i.e.,
shift to the right hemisphere, which is the proper mode for sex.
- We can acknowledge other people's hemisphere-preference, to
enhance our communication. After just a few minutes of
conversation, we might be able to discern their preference by
observing the following qualities in their speech. A
right-hemisphere person tends to exhibit more feeling, emotion,
visual imagery, humor, and a musical quality in the voice. A
left-hemisphere person prefers logic, details, and a
conversational structure that has an obvious direction and
purpose. When we talk to either type of person, we can use the
respective qualities so that we will be understood more easily.
However, we need to give our listener a balance; many public
speakers intentionally make frequent changes between the left and
right hemisphere -- facts and emotions -- to keep the audience
interested.