| Description |
The Liking Task was designed to determine the contributions made to memory by the hippocampus and the amygdala. The expected results, based on the Attribute Model of memory and other research, would be that the hippocampus mediates storage of linguistic or spatial information, while the amygdala is involved in the storage of affective situations, ones in which reinforcement or punishment are involved. To separate these aspects of a situation, it was necessary to design a task that consisted of components of affective ratings and recognition ratings. Zajonc (1972) determined that people tend to prefer things they have seen over similar things that they have not seen before. He called this the "Mere Exposure Effect". Four general types of subjects were used. The following two groups of control subjects were tested: one group of control subjects had partial complex; epilepsy; and the other group of control subjects did not suffer from any type of seizure. The other two groups consisted of people who had undergone surgery for epilepsy: one group had part of their temporal lobe and hippocampus; resected whereas the other group had part or all of their amygdala removed, as well as the temporal lobe and/or hippocampus. Each subject was shown, on a computer, a series of pictures and words. Then they were shown either two pictures or two words, one that they had seen before and another similar one. The subjects were then asked which of the two they preferred. Next, the subjects were again shown two stimuli, one they had seen before and one they had not, and asked which of the two they recognized. All control subjects and those with only temporal lobe resections preferred the stimuli they had seen before. However, the subjects who also had their amygdala removed did not show this liking effect. However, all groups performed well on the recognition part of the task. These results support the theory that the amygdala plays a role in the affective component of a memory. The results did not support the idea that the hippocampus mediates spatial and linguistic information. |
