CINGULATE GYRUS (Literally “ring- shaped ridge”)

The cortical part of the limbic system of the brain, lying just above the corpus callosum (plate 1).Although the functions of this structure are not yet fully determined, there are some promising leads. Monkeys have shown an increased urge to eat when this area was stimulated with an electrode; therefore it seems to play a role in hunger (Robinson and Mishkin, 1962). It also appears to be involved in certain types of avoidance conditioning. When lesions were made in the anterior portion of the gyrus, cats readily learned an active response in which they moved or jumped to avoid a shock area, but they had trouble learning a passive response—that is, withholding their approach to food in order to avoid a shock. Cats with posterior cin- gulate lesions showed the opposite pattern (McCleary, 1961). Further experiments with monkeys showed a reduced ability to retain already acquired active responses following a cingulate lesion (Pribram and Weiskrantz, 1957).Apparently the cingulate gyrus plays a part not only in hunger, but in learning and retention. Though it appears that different parts are involved in different types of responses, both the structural and functional details have still to be discovered