Dobryakova Ekaterina, Genova Helen, Schneider Veronica, Chiaravalloti Nancy D, Spirou Angela, Wylie Glenn R, DeLuca John
Center for Traumatic Brain Injury Research, Kessler Foundation, East Hanover, NJ, USA; Department of Physical Medicine and Rehabilitation, Rutgers-New Jersey Medical School Newark, NJ, USA.
Department of Physical Medicine and Rehabilitation, Rutgers-New Jersey Medical School Newark, NJ, USA; Center for Neuropsychology and Neuroscience Research, Kessler Foundation, West Orange, NJ, USA.
Cortex. 2020 May;126:16-25. doi: 10.1016/j.cortex.2020.01.003. Epub 2020 Jan 24.
While cognitive fatigue is experienced by up to 80% of individuals with traumatic brain injury (TBI), little is known about its neural underpinnings. We previously hypothesized that presentation of rewarding outcomes leads to cognitive fatigue reduction and activation of the striatum, a brain region shown to be associated with cognitive fatigue in clinical populations and processing of rewarding outcomes. We have demonstrated this in individuals with multiple sclerosis. Here, we tested this hypothesis in individuals with TBI. Twenty-one individuals with TBI and 24 healthy participants underwent functional magnetic resonance imaging. Participants performed a task during which they were presented with 1) the Outcome condition where they were exposed to monetary rewards, and 2) the No Outcome condition that served as the control condition and was not associated with monetary rewards. In accordance with our hypothesis, results showed that attainment of rewarding outcomes leads to cognitive fatigue reduction in individuals with TBI, as well as activation of the striatum. Specifically, we observed a significant group by condition interaction on fatigue scores driven by the TBI group reporting lower levels of fatigue after the Outcome condition. fMRI data revealed a significant main-effect of condition in regions previously implicated in outcome processing, while a significant group by condition interaction was observed in the left ventral striatum as revealed by a priori region of interest analysis. Results suggest that a salient motivator can significantly reduce fatigue and that outcome presentation leads to increased activation of the ventral striatum in TBI. These findings can inform the development of future non-pharmacological cognitive fatigue treatment methods and contribute to the growing body of evidence showing the association between cognitive fatigue and the striatum.
虽然高达80%的创伤性脑损伤（TBI）患者会经历认知疲劳，但其神经基础却鲜为人知。我们之前曾假设，呈现奖励性结果会导致认知疲劳减轻以及纹状体激活，纹状体是一个在临床人群中显示与认知疲劳及奖励性结果处理相关的脑区。我们已在多发性硬化症患者中证实了这一点。在此，我们在TBI患者中对这一假设进行了测试。21名TBI患者和24名健康参与者接受了功能磁共振成像检查。参与者执行一项任务，在此期间他们会面临1）结果条件，即他们会接触到金钱奖励；2）无结果条件，作为对照条件，与金钱奖励无关。与我们的假设一致，结果显示，获得奖励性结果会导致TBI患者的认知疲劳减轻，以及纹状体激活。具体而言，我们观察到由条件驱动的疲劳得分上存在显著的组间交互作用，TBI组在结果条件后报告的疲劳水平较低。功能磁共振成像数据显示，在先前涉及结果处理的区域中存在显著的条件主效应，而在先验感兴趣区域分析中，在左腹侧纹状体中观察到显著的组间条件交互作用。结果表明，一个显著的激励因素可以显著减轻疲劳，并且结果呈现会导致TBI患者腹侧纹状体激活增加。这些发现可为未来非药物性认知疲劳治疗方法提供依据，并为越来越多显示认知疲劳与纹状体之间关联的证据做出贡献。
