Modulation of value representation by social context in the primate orbitofrontal cortex

Abstract

The authors note that on page 2126, left column, lines 6-10 of the abstract, "Behaviorally, monkeys discriminated between cues signaling small and large rewards, and between cues signaling rewards to self only and reward to both self and another monkey, with a preference for the former over the latter in both instances," should instead appear as "Behaviorally, monkeys discriminated between cues signaling large and small rewards, and between cues signaling rewards to self only and reward to both self and another monkey, with a preference for the former over the latter in both instances."www.pnas.org/cgi

Activity of striatal neurons reflects social action and own reward

“…Eye fixation patterns revealed that the recorded animal closely observed the conspecific's reward-predicting stimuli, face and spout ( Fig. 1 E and F), confirming previous observations during social interaction of nonhuman primates (3,8,19). Without being required, the passive, nonacting animal maintained its hand on the resting key (Fig.…”

“…The principal hypothesis is stated in the unrestricted model Y = β 0 + β 1 A + β 2 W + β 3 Z + β 4 AW + β 5 AZ + e; [1] where Y is neuronal activity, A is actor (recorded animal acts = 1, conspecific acts = 0), W is reward for recorded animal (reward = 1, no reward = 0), and Z is reward for conspecific animal (reward = 1, no reward = 0). The two models of most interest were Y = β 0 + β 1 A + β 2 W + β 4 AW + e; [2] which tests neuronal coding of actor for own reward, and Y = β 0 + β 1 A + β 3 Z + β 5 AZ + e; [3] which tests neuronal coding of actor for conspecific's reward. We also included a model that tests coding of reward only Y = β 0 + β 2 W + β 3 Z + e: [4] All models implied by the unrestricted model (Eq.…”

“…Recent evidence suggests separate coding of social reward and action in the neuronal activity of distinct frontal cortical areas of monkeys. Reward neurons distinguish between own and other's reward (3,4) and show differential activity during social competition (5) and movement (6). Action neurons respond to the observation of movement of social partners (7), differentiate between own and other's movements (8), and detect other's error commission (9).…”

Neural mechanisms tracking popularity in real-world social networks

“…The observed correlations between target popularity and activity in valuation and social cognition regions confirmed our primary hypotheses, which led to our second question: Do the two systems track popularity in parallel (independently) or serially, with one system assuming a primary role that mediates the popularity-activity relationship for the other? We predicted the valuation system would function as mediator based on the aforementioned literatures in social psychology [i.e., it is highstatus individuals' social importance that motivates others to predict their mental states (25)(26)(27)(28)] and nonhuman primate neurophysiology [i.e., neurons in valuation regions encode social value and signal presence of high-status group members (19)(20)(21)(22)]. To test this prediction, we performed multilevel mediation analyses, assessing whether valuation system activity explains the observed relationship between target popularity and social cognition system activity.…”

“…These densely interconnected regions (13), henceforth referred to collectively as the "valuation system," are consistently implicated in processing the affective value and motivational significance of various stimuli, including other people (13)(14)(15)(16)(17)(18). Although human neuroscience research has yet to investigate sociometric popularity, nonhuman primate researchers have found that neurons in these regions signal group members' dominance rank (19)(20)(21) and proposed that the vmPFC, VS, and amygdala interact to encode, monitor, and signal other individuals' social value (22). If tracking group members' popularity depends on the motivational significance…”