Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 EN Nijmegen, The Netherlands,
Department of Psychiatry, Radboud University Medical Centre, Nijmegen, The Netherlands.
J Neurosci. 2019 May 15;39(20):3934-3947. doi: 10.1523/JNEUROSCI.3071-18.2019. Epub 2019 Mar 8.
Cognitive control is necessary for goal-directed behavior, yet people treat cognitive control demand as a cost, which discounts the value of rewards in a similar manner as other costs, such as delay or risk. It is unclear, however, whether the subjective value (SV) of cognitive effort is encoded in the same putatively domain-general brain valuation network implicated in other cost domains, or instead engages a distinct frontoparietal network, as implied by recent studies. Here, we provide rigorous evidence that the valuation network, with core foci in the ventromedial prefrontal cortex and ventral striatum, also encodes SV during cognitive effort-based decision-making in healthy, male and female adult humans. We doubly dissociate this network from frontoparietal regions that are instead recruited as a function of decision difficulty. We show that the domain-general valuation network jointly and independently encodes both reward benefits and cognitive effort costs. We also demonstrate that cognitive effort SV signals predict choice and are influenced by state and trait motivation, including sensitivity to reward and anticipated task performance. These findings unify cognitive effort with other cost domains, and suggest candidate neural mechanisms underlying state and trait variation in willingness to expend cognitive effort. Subjective effort costs are increasingly understood to diminish cognitive control over task performance and can thus undermine functioning across health and disease. Yet, we are only beginning to understand how decisions about cognitive effort are made. A key question is how subjective values are computed. Recent work suggests that the value of cognitive effort might be computed by networks that are distinct from those involved in other domains like intertemporal and risky decision-making, implying distinct mechanisms. Here we demonstrate that the domain-general network also encodes effort-discounted value, linking cognitive effort closely with other domains. Our results thus elucidate key mechanisms supporting decisions about cognitive effort, and point to candidate neural targets for intervention in disorders involving impaired cognitive motivation.
认知控制对于目标导向行为是必要的,但人们将认知控制需求视为一种成本,这种成本会以类似于其他成本(如延迟或风险)的方式降低奖励的价值。然而,目前尚不清楚认知努力的主观价值(SV)是否是在与其他成本领域相关的相同假定的大脑估值网络中编码的,或者是由最近的研究暗示的一个独特的额顶网络编码的。在这里,我们提供了严格的证据,表明估值网络,其核心焦点在腹内侧前额叶皮层和腹侧纹状体,也在健康的男性和女性成年人类的基于认知努力的决策中编码 SV。我们将该网络与额顶区域双重分离,额顶区域是作为决策难度的函数而被招募的。我们表明,该领域通用的估值网络共同且独立地编码奖励收益和认知努力成本。我们还表明,认知努力的 SV 信号预测选择,并受到状态和特质动机的影响,包括对奖励的敏感性和预期的任务表现。这些发现将认知努力与其他成本领域统一起来,并表明候选的神经机制是状态和特质变化的基础,即在愿意付出认知努力方面的变化。主观努力成本越来越被理解为会降低对任务表现的认知控制,从而破坏健康和疾病中的功能。然而,我们才刚刚开始了解关于认知努力的决策是如何做出的。一个关键问题是主观价值是如何计算的。最近的工作表明,认知努力的价值可能是由与那些涉及跨时间和冒险决策等其他领域的网络不同的网络计算的,这意味着存在不同的机制。在这里,我们证明了通用网络也编码了努力折扣的价值,将认知努力与其他领域紧密联系起来。我们的结果因此阐明了支持认知努力决策的关键机制,并为涉及认知动机受损的障碍的干预提供了候选的神经靶点。