The Two Brains and How We Learn

Humans are unique from all the other animals because we are capable of communicating symbolically with each other. Our ability comes from the complex structure called the cerebral cortex, which is separated into two hemispheres.

Each hemisphere of the brain contains different mental functions. Through experiments with various patients with damaged areas of their brain, scientists are able to pinpoint the locations of speech, language, and comprehension. They have also discovered that the two brains are not symmetrical. For example, a patient "Landry" had a stroke, which damaged his Broca's Area in his left brain, thus he can only comprehend nouns and verbs. Other tests show that the Wernicke's Area in the left brain controls speech and comprehension. The right side of the brain recognizes shapes and patterns. However, in the case of 'Paulette', her inability to recognize places and faces and the damage to both sides of her brain indicate that both side work together to achieve recognition.

Studies also show that culture has an effect on the organization of the brain. Scientists discovered that when Japanese hear sounds of nature they process the sounds in their left brains because they treat these sounds as language. Americans process the sounds in their right brain because they have categorized nature sounds as noise. In another study, the aborigine children of Australia were found to have better visual and spatial memory then those of Caucasian children. Thus it can be seen that culture can have a direct impact on the development of the brain.

Another factor that can influence the development of the brain is sex. Studies with rats have shown that female brains are thicker in the left hemisphere, indicating that, in general, female brains are more language oriented. Male rats have thicker right hemispheres, showing that male brains are better at spatial functions. Hormones that are released during the development of children both in the womb and out of the womb affect the brain. For example, it has been shown that adrenaline released during stress decreases the amount of testosterone going into the womb. A statistical analysis concluded that more homosexuals were born during the time of World War II then any other period. One such individual was tested for his reaction to estrogen and his brain responded to estrogen, indicated that he had a female oriented brain. However it is not only hormones that tend to differentiate the male and female brain. Their upbringings also influence what kind of stimulation they receive in their brains. An experiment showed that mothers tend to encourage boys to be active and to explore the environment while they tend to talk more to girls.

The fact of the matter is that human brains are probably influenced both by genetics and experience. Scientists are beginning to explore the various possibilities but many questions are still unanswered. They have only touched the tip of a very large iceberg.

Do we see the world because it is the way the world is, or do we see the world because of how we are built? The evidence is for constructive realism. Just because someone does not understand how electricity works does not mean electricity does not exists. Realty is a construct of our facilities. The theory of constructive realism does not only apply to a visual spectrum, but to other senses as well.

It is clear that humans not only mentally categorize concepts, words, and ideas, but they are also physically categorized them in the brain. Patients with specifically damaged areas of the brain have specific afflictions that causes them to lose the ability to understand grammatically complex speech, or the ability to give things names, or things that are alive. Thus it can be seen how neuroscience can benefit from other cognitive studies and vise versa.

There always seem to be an enormous gap between actual thought and the brain itself. However, this evidence connecting culture and the development of the brain narrows this gap because it shows how subconscious thought can actually affect the brain. It was interesting to see how the brain is different in males and females and how a mother can actually affect the sexual orientation of her child. I never consciously realized that culture had such an impact on the development of the brain. What about those who are exposed to two or more different cultures? In this day and age, it is not unlikely for a person to have relatives and parents of different ethnicities. How does multi-culturalism affect the brain? Since scientists have located the general areas for speech and comprehension, do the same areas apply for those who know more than one language? How are the differences in grammatical structures kept apart and distinct from one another? Do multi-lingual individuals have a larger brain mass in the language areas? Perhaps these questions will be answered when we begin to fully understand how the brain works.