Dryzer Michael, Chib Vikram S
Department of Biomedical Engineering, Johns Hopkins School of Medicine, 720 Rutland Avenue, Baltimore, MD, 21205, USA.
Kavli Neuroscience Discovery Institute, 725 N. Wolfe Street, Johns Hopkins University, Baltimore, MD, 21205, USA.
bioRxiv. 2024 Dec 10:2024.12.06.627274. doi: 10.1101/2024.12.06.627274.
Fatigue is a state of exhaustion that influences our willingness to engage in effortful tasks. While both physical and cognitive exertion can cause fatigue, there is a limited understanding of how fatigue in one exertion domain (e.g., cognitive) affects decisions to exert in another (e.g., physical). We use functional magnetic resonance imaging (fMRI) to measure brain activity while human participants make decisions to exert prospective physical effort before and after engaging in a cognitively fatiguing working memory task. Using computational modeling of choice behavior, we show that fatiguing cognitive exertion increases participants' subjective costs of physical effort compared to a baseline rested state. We describe how signals related to fatiguing cognitive exertion in the dorsolateral prefrontal cortex influence physical effort value computations instantiated by the insula, thereby increasing an individual's subjective valuation of prospective physical effort while cognitively fatigued. Our results support the idea of a general fatigue signal that integrates exertion-specific information to guide effort-based choice.
疲劳是一种疲惫状态，会影响我们从事费力任务的意愿。虽然身体和认知上的 exertion 都可能导致疲劳，但对于一个 exertion 领域（如认知）的疲劳如何影响在另一个领域（如身体）的 exertion 决策，人们的了解有限。我们使用功能磁共振成像（fMRI）来测量人类参与者在进行认知疲劳的工作记忆任务前后决定进行预期身体 exertion 时的大脑活动。通过对选择行为的计算建模，我们表明与基线休息状态相比，疲劳的认知 exertion 会增加参与者身体 exertion 的主观成本。我们描述了背外侧前额叶皮层中与疲劳认知 exertion 相关的信号如何影响由脑岛实例化的身体 exertion 价值计算，从而在认知疲劳时增加个体对预期身体 exertion 的主观估值。我们的结果支持了一种一般疲劳信号的观点，该信号整合了特定于 exertion 的信息以指导基于努力的选择。
