| Psychologists have developed a variety of techniques to study the brain so that they can better predict, control, and explain behavior. One early method was proposed by Franz Gall, who in the early 1800s measured the bumps on people's skulls and tried to relate them to various behavior characteristics. While this method, called phrenology, never produced significant results, it did set the stage for later methods of identifying the functions of particular parts of the brain.
In the 1930s it was discovered that if the frontal lobes were disconnected from the rest of the brain, violent or extremely emotional mental patients became calm. This procedure, called prefrontal lobotomy, was for a time popular in treating severe behavior problems. However, studies showed that prefrontal lobotomy had negative side effects: lobotomy patients showed little emotion, had no social inhibitions, and had trouble solving problems. Because of these behavioral side effects, and because of the ethical implications in cutting out part of a brain, lobotomies are no longer performed to treat mental disorders. Currently, the most common biological method for treating mental disorders is drug therapy. An important technique now used for studying the brain involves the electrical stimulation of specific areas. The function of the limbic system was discovered accidentally in 1954 by James Olds and Peter Milner, who were testing the effects of electrical stimulation on the reticular formation in rats and placed an electrode (an extremely thin insulated wire) in the septal area by mistake. This part of the limbic system produces a pleasurable sensation when stimulated. When the rats learned that they could control the electrical stimulation and thus the pleasure by pressing a lever, they pressed it thousands of times per hour. Electrical stimulation of the brain (ESB) has a potent reinforcing effect, which means the subject will repeat whatever behavior led to the pleasurable sensation. The reinforcing effects of ESB have been found in a variety of animals, including humans. Recent research suggests that ESB involves endorphin synapses (Wise & Bozarth, 1984). Another demonstration of the effects of brain stimulation on behavior was described by Jos Delgado (1969). Delgado implanted an electrode in the brain of a bull, and then entered the bull ring armed with a radio transmitter. When the bull charged toward him, Delgado pressed a button, causing the bull to stop and turn away thus demonstrating the brain's control over behavior. Electrical stimulation of the human brain can be used to help people with behavior problems, as demonstrated by the research of Wilder Penfield (1975). Penfield used brain stimulation to locate malfunctioning areas of the brain. His purpose was to find the areas of the brain causing a type of epilepsy in which a number of neurons begin to fire wildly. When the area was located, the malfunctioning part was removed. In the course of such brain surgery, Penfield discovered that stimulating areas of the cerebral cortex could produce vivid memories (although later research hasn't always been able to validate the accuracy of the memories). |
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