Is it possible our brain is actually two separate mental system? When we think about the brain, we know that it is divided into two hemispheres. The left and the right. The left actually controls the right side of the body and the right controls the left. They are connected by the corpus callosum. The corpus callosum is the major line of communication between the two. What would happen if that line of communication was cut?
Robert W. Perry (19131994) pioneered that thought. He actually tested that theory on animals. A cat underwent surgery to cut the corpus callosum. Now that the connection to the two halves of the brain cannot communicate with each other he has begun his test. He covered the left eye of the cat and had it learn how to go through a maze. Once the cat mastered the maze, he had the cat use his left eye and covered the right. The cat did not remember how to go through the maze, in fact it had to completely relearn the maze.
Testing human brains Perry was joined in his research by Michael
Gazzania. In the 1960s they turned their attention to human subjects. They were able to conduct some tests on patients that had to have the radical surgery to cut their corpus callosum. These patients had severe epilepsy and seizures and it was a last resort. They conducted visual, touch and auditory tests. These tests consisted of a large variety of mental capabilities of the patients. It must be stated that there were no obvious personality changes due to this surgery. All the patient’s personality wits etc. remained the same. However, some very significant findings were uncovered. Your left brain is better at speaking and the right brain is better at artistic and symbolic reasoning. Together they combine these two skills and you would not notice if one side was doing the majority of the work. In the split brain however, we see from the test that in fact the two brains are operating separately. In the visual test it was learned that when patients were asked what an object was on their left side, they could not say what it was. This was due to the fact that the right hemisphere brain controlling the left side was not good at speech. The
patients knew what the object was when they were allowed to point, but could not physically speak the words. When that right hemisphere was shown a picture of say a cigarette, they could not say what the picture was. When they were asked to feel for an object that they could not see that closely related to that item there right brain was able to pull out an ashtray. The right brain is very good at symbolic reasoning, so even though they could not name the item the brain paired the ashtray object with the picture of the cigarette. Patients were asked to spell words with blocks by feel with the left hand. They were able to do this easily. However, when asked to name the word they just spelled they could not.
Conclusion The two halves of your brain have specialized skills. If they cannot communicate with each other you could have issues like discussed previously. The findings of this study will help phycologist better set up a treatment for patients who’s brains do not communicate with each other, such as those that have had a stroke or major head injury.