Division of Epileptology, University of Bonn, Bonn, Germany.
Computation and Neural Systems, California Institute of Technology, Pasadena, CA, USA.
Cereb Cortex. 2019 Jan 1;29(1):265-272. doi: 10.1093/cercor/bhx330.
The amygdala plays an important role in the computation of internal reward signals. In animals it has been shown to enable a stimulus to indicate the current value of a reinforcer. However, the exact nature of the current value representations in humans remains unknown. Specifically, do neurons of the human amygdala represent current value signals only in tasks requiring valuation? We recorded from 406 neurons in the amygdala, orbitofrontal cortex, parahippocampal cortex, entorhinal cortex, and hippocampus of 6 neurosurgical patients while subjects repeatedly viewed 40 different pictures of sweet or salty "junk food" items in 2 different tasks. Neural activity during stimulus inspection in a valuation task reflected food preferences in the amygdala, orbitofrontal cortex, hippocampus, and entorhinal cortex. Notably, only left amygdala activity represented these food preferences even in a sweet-salty classification task. Valuation signals of the left amygdala thus appear to be stimulus-, not-task driven.
杏仁核在内部奖励信号的计算中起着重要作用。在动物研究中，杏仁核可以使刺激物指示强化物的当前价值。然而，人类当前价值表示的确切性质仍然未知。具体来说，人类杏仁核的神经元是否仅在需要评估的任务中表示当前价值信号？我们在 6 名神经外科患者的杏仁核、眶额皮层、海马旁回、内嗅皮层和海马中记录了 406 个神经元，同时让受试者在 2 个不同的任务中反复观看 40 种不同的甜或咸“垃圾食品”图片。在评估任务中刺激检查期间的神经活动反映了杏仁核、眶额皮层、海马和内嗅皮层对食物的偏好。值得注意的是，即使在甜咸分类任务中，只有左杏仁核的活动代表了这些食物偏好。因此，左杏仁核的评估信号似乎是由刺激驱动的，而不是由任务驱动的。
