Translational Research in Affective Disorders Laboratory, Department of Psychology, Emory University, Atlanta, GA, USA.
Department of Psychiatry and Behavioral Science, Emory University, Atlanta, GA, USA.
Nat Hum Behav. 2021 Mar;5(3):378-388. doi: 10.1038/s41562-020-00972-y. Epub 2020 Nov 23.
The ventral striatum is believed to encode the subjective value of cost-benefit options; however, this effect has notably been absent during choices that involve physical effort. Previous work in freely moving animals has revealed opposing striatal signals, with greater response to increasing effort demands and reduced responses to rewards requiring effort. Yet, the relationship between these conflicting signals remains unknown. Using functional magnetic resonance imaging with a naturalistic maze-navigation paradigm, we identified functionally segregated regions within the ventral striatum that separately encoded effort activation, movement initiation and effort discounting of rewards. In addition, activity in regions associated with effort activation and discounting oppositely predicted striatal encoding of effort during effort-based decision-making. Our results suggest that the dorsomedial region hitherto associated with action may instead represent the cost of effort and raise fundamental questions regarding the interpretation of striatal 'reward' signals in the context of effort demands. This has implications for uncovering the neural architecture underlying motivated behaviour.
腹侧纹状体被认为编码了成本效益选项的主观价值；然而，在涉及体力活动的选择中，这种效应显然不存在。先前在自由活动的动物中的研究揭示了相反的纹状体信号，随着努力需求的增加，反应更大，而需要努力的奖励反应减少。然而，这些冲突信号之间的关系仍然未知。使用自然迷宫导航范式的功能磁共振成像，我们在腹侧纹状体中确定了功能上分离的区域，这些区域分别编码了努力激活、运动启动和努力折扣奖励。此外，与努力激活和折扣相关的区域的活动相反地预测了基于努力的决策中努力的纹状体编码。我们的结果表明，迄今与行动相关的背内侧区域可能代表努力的成本，并提出了关于在努力需求背景下解释纹状体“奖励”信号的基本问题。这对于揭示动机行为的神经结构具有重要意义。
