Bilateral neurotoxic amygdala lesions in rhesus monkeys (Macaca mulatta): Consistent pattern of behavior across different social contexts

摘要

Although the amygdala has been repeatedly implicated in normal primate social behavior, great variability exists in the specific social and nonsocial behavioral changes observed after bilateral amygdala lesions in nonhuman primates. One plausible explanation pertains to differences in social context. To investigate this idea, we measured the social behavior of amygdala-lesioned and unoperated rhesus monkeys (Macaca mulatta) in two contexts. Animals interacted in four-member social groups over 32 test days. These animals were previously assessed in pairs (), and were, therefore, familiar with each other at the beginning of this study. Across the two contexts, amygdala lesions produced a highly consistent pattern of social behavior. Operated animals engaged in more affiliative social interactions with control group partners than did control animals. In the course of their interactions, amygdala-lesioned animals also displayed an earlier decrease in nervous and fearful personality qualities than controls. The increased exploration and sexual behavior recorded for amygdala-lesioned animals in pairs was not found in the four-member groups. We conclude that the amygdala contributes to social inhibition and this function transcends various social contexts.