An assessment of the reinforcing properties of foods after amygdaloid lesions in rhesus monkeys.

Abstract
The reinforcing strengths of foods were assessed in rhesus monkeys before and after bilateral radio-frequency lesions of the lateral amygdala (n = 4), basolateral amygdala (n = 4), and total amygdala (n = 3). None of these lesions altered preoperative preferences between 3 highly palatable foods. The lesions had no discernible effect on the animals'' responses to different food rewards as measured by a progressive ratio schedule, although performance on this schedule proved sensitive to the size and type of food reward and to the degree of deprivation. Amygdalectomy seems to leave a normal appreciation of at least this 1 class of rewards, foods. The dietary changes typically seen after amygdalectomy, such as meat eating, which were also observed in the same animals, probably reflect a loss of neophobia.