Our brain, like the rest of our anatomy, is made up of two halves, a left brain a right brain. There's a big fold that goes from front to back in our brain, essentially dividing it into two distinct and separate parts. Well, almost separate. They are connected to each other by a thick cable of nerves at the base of each brain. This sole link between the two giant processors is called the corpus collosum. Think of it as an Ethernet cable or network connection between two incredibly fast and immensely powerful computer processors, each running different programs from the same input.
The left side of our body is "wired" to the right side of our brain, and vice versa. For whatever reason nature did this cross-over, it applies even to our eyes, which process a majority of their sensory data on opposite sides of the brain.
We can thank Nobel Prize Winner (1981) Roger Sperry for this next contribution. Sperry conducted what are sometimes called the "split-brain" experiments. Here's how it went: A patient suffering from uncontrolled seizures had an area of his brain removed by surgery in an attempt to control his illness. This area just happened to be the corpus collosum, which was suspected of having developed lesions (short circuits).
Following his surgery, Sperry's patient seemed completely normal -- almost. A series of tests were conducted where each "half" of the patient was isolated from the other. Different visual and tactile information could then be presented to the patient's left or right side, without the other side knowing. The results were astounding.
With their communications link severed, each side of the patient's brain was functioning independently. Although this did not prevent his ability to walk, talk and eat, some unexpected findings were encountered in some of the higher brain functions when each side was examined independently of the other.
The right hand and eye could name an object, such as a pencil, but the patient could not explain what it was used for. When shown to the left hand and eye, the patient could explain and demonstrate its use, but could not name it. Further studies showed that various functions of thought are physically separated and localized to a specific area on either the left or right side of the human brain. This functional map is consistent for an estimated 70 to 95 percent of us.
The main theme to emerge... is that there appear to be two modes of thinking, verbal and nonverbal, represented rather separately in left and right hemispheres respectively and that our education system, as well as science in general, tends to neglect the nonverbal form of intellect. What it comes down to is that modern society discriminates against the right hemisphere.
-Roger Sperry (1973)
Upon completing the map, it was becoming clear to researchers that each side of the brain had a characteristic way that it both interpreted the world and reacted to it. The chart below will help illustrate the characteristics which are known to reside on each side of our brains.
LEFT BRAIN FUNCTIONS
uses logic
detail oriented
facts rule
words and language
present and past
math and science
can comprehend
knowing
acknowledges
order/pattern perception
knows object name
reality based
forms strategies
practical
safe
RIGHT BRAIN FUNCTIONS
uses feeling
"big picture" oriented
imagination rules
symbols and images
present and future
philosophy & religion
can "get it" (i.e. meaning)
believes
appreciates
spatial perception
knows object function
fantasy based
presents possibilities
impetuous
risk taking
Our personality can be thought of as a result of the degree to which these left and right brains interact, or, in some cases, do not interact. It is a simplification to identify "left brain" types who are very analytical and orderly. We likewise certainly know of the artistic, unpredictability and creativity of "right brain" types. But each of us draws upon specific sides of our brain for a variety of daily functions, depending on such things as our age, education and life experiences. The choices of which brain is in control of which situations is what forges our personalities and determines our character.
Experiments show that most children rank highly creative (right brain) before entering school. Because our educational systems place a higher value on left brain skills such as mathematics, logic and language than it does on drawing or using our imagination, only ten percent of these same children will rank highly creative by age 7. By the time we are adults, high creativity remains in only 2 percent of the population.
The Brain and Intelligence
There is a known correlation between brain size and intellectual ability. Homo Erectus, our distant ancestor, had a brain size of about 1200 cc. Modern Homo Sapiens have an average brain of about 1400 cc. Oddly, the Neanderthal people who failed to evolve into humans already had a brain size of 1500 cc -- larger than modern man. Obviously then, its not only how big the brain is as much as how it is configured. This is further evidenced by the fact that we have known genius brains measuring as small as 1000 cc. and as large as 2000 cc.
Increasing brain size was a risky endeavor for human evolution. The brain requires a highly stable temperature and a supply of high protein and energy. One quarter of our caloric intake is used for brain energy consumption.
The War of the Brains
The two brains not only see the world in vastly different ways but, in our current society, the left side just "doesn't get" what the right side is all about. It tends to dismiss anything significant coming into consciousness from its "flaky" cranial twin. Sometimes two sides can actually disagree, resulting in our perception of emotional turmoil from the expressive protests of right brain.
Our conscious mind can only focus on data from one brain at a time. We can switch from one side to the other very quickly (with our corpus collosum intact) but that's not always the most efficient way to act and eventually ultimate authority to enter consciousness is delegated to one brain or the other. In our modern world, this battle is almost always won by the left brain.
It appears that most people will never reach their maximum potential because of compromises that have been made between these two governing bodies. Sometimes skills which the right brain can perform better are routinely handled, with less skill, by the left brain. Ideally, both brains work together in people with optimum mental ability. This coordinating ability may be the key to superior intellectual abilities. In most people, however, the left brain takes control, choosing logic, reasoning and details over imagination, holistic thinking and artistic talent.
Methods have been devised to "shut off" the left brain, allowing the right side to have its say. Creative writing courses often use this method to combat "writer's block." The logical left side is easily bored by lack of input and tends to "doze off" during such activities as meditation (repeating a mantra or word over and over) or in sensory deprivation environments. The right brain is then able to "sneak" into our consciousness, filling our minds with emotional and visual vignettes and freely associated images. All too quickly, though, the left brain will assert itself and dispense with these irrational images, asserting its Spock-like logical dominance and the right brain will have to be content to find expression in dreams.