報酬および嫌悪刺激の予期に関わるアカゲザル前部帯状回の神経細胞活動

抄録

Several lines of evidence suggest that the anterior cingulate cortex (ACC) is crucially involved in evaluation of affective significance and executive behavior essential for existence of animals. To understand neuronal mechanisms of this function, we recorded single neuronal activities in the ACCs of two macaque monkeys performing a color discrimination task associated with reward or aversive electric stimulation (ES): when the monkey pressed a lever, a fixation cue appeared for 0.5-1.5 s followed by a green or red prediction cue (PC) for 1.0 s; green cued a liquid reward, red cued ES. We recorded 294 neurons and 111 (37.8%) of them responded to the PCs. To test the significance of these responses, we examined the neuronal activities under the reversed condition where a cue, which predicted reward under the normal condition, predicted ES, and vice versa. We found that 47.4% of neurons in the ACC responded to the affective significance of visual cues and that only one neuron (3.2%) responded to visual cues themselves. Our results suggest that the ACC predicts future events and contributes to the selection of adaptive responses.