Ghazizadeh Ali, Hikosaka Okihide
Bio-intelligence Research Unit, Electrical Engineering Department, Sharif University of Technology, Tehran 11365-11155, Iran.
School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran 19395-5746, Iran.
Sci Adv. 2021 May 12;7(20). doi: 10.1126/sciadv.abe0693. Print 2021 May.
Recent evidence implicates both basal ganglia and ventrolateral prefrontal cortex (vlPFC) in encoding value memories. However, comparative roles of cortical and basal nodes in value memory are not well understood. Here, single-unit recordings in vlPFC and substantia nigra reticulata (SNr), within macaque monkeys, revealed a larger value signal in SNr that was nevertheless correlated with and had a comparable onset to the vlPFC value signal. The value signal was maintained for many objects (>90) many weeks after reward learning and was resistant to extinction in both regions and to repetition suppression in vlPFC. Both regions showed comparable granularity in encoding expected value and value uncertainty, which was paralleled by enhanced gaze bias during free viewing. The value signal dynamics in SNr could be predicted by combining responses of vlPFC neurons according to their value preferences consistent with a scheme in which cortical neurons reached SNr via direct and indirect pathways.
最近的证据表明，基底神经节和腹外侧前额叶皮层（vlPFC）都参与价值记忆的编码。然而，皮层和基底神经节节点在价值记忆中的相对作用尚未得到充分理解。在这里，对猕猴腹外侧前额叶皮层和黑质网状部（SNr）进行的单神经元记录显示，SNr中的价值信号更大，不过该信号与腹外侧前额叶皮层的价值信号相关，且起始时间相当。在奖励学习数周后，价值信号在许多物体（>90个）上持续存在，并且在两个区域中都能抵抗消退，在腹外侧前额叶皮层中还能抵抗重复抑制。两个区域在编码预期价值和价值不确定性方面表现出相当的精细度，这在自由观看期间伴随着增强的注视偏向。根据vlPFC神经元的价值偏好组合其反应，可以预测SNr中的价值信号动态，这与一种皮层神经元通过直接和间接通路到达SNr的模式一致。
