| Abstrakt: |
Lesion studies in macaques suggest dissociable functions of the orbitofrontal cortex (OFC) and medial frontal cortex (MFC), with OFC being essential for goal-directed decision-making and MFC supporting social cognition. Bilateral amygdala damage results in impairments in both of these domains. There are extensive reciprocal connections between these prefrontal areas and the amygdala; however, it is not known whether the dissociable roles of OFC and MFC depend on functional interactions with the amygdala. To test this possibility, we compared the performance of male rhesus macaques (Macaca mulatta) with crossed surgical disconnection of the amygdala and either MFC (MFC Χ AMY, n = 4) or OFC (OFC Χ AMY, n = 4) to a group of unoperated controls (CON, n = 5). All monkeys were assessed for their performance on two tasks to measure the following: (1) food-retrieval latencies while viewing videos of social and nonsocial stimuli in a test of social interest and (2) object choices based on current food value using reinforcer devaluation in a test of goal-directed decision-making. Compared with the CON group, the MFC Χ AMY group, but not the OFC Χ AMY group, showed significantly reduced food-retrieval latencies while viewing videos of conspecifics, indicating reduced social valuation and/or interest. By contrast, on the devaluation task, group OFC Χ AMY, but not group MFC Χ AMY, displayed deficits on object choices following changes in food value. These data indicate that the MFC and OFC must functionally interact with the amygdala to support normative social and nonsocial valuation, respectively. [ABSTRACT FROM AUTHOR] |
