Esposito Fabrizio, Otto Tobias, Zijlstra Fred R H, Goebel Rainer
Department of Medicine and Surgery, University of Salerno, Baronissi (Salerno), Italy; Department of Cognitive Neuroscience, Maastricht University, Maastricht, The Netherlands.
Department of Work and Social Psychology, Maastricht University, Maastricht, The Netherlands.
PLoS One. 2014 Apr 4;9(4):e94222. doi: 10.1371/journal.pone.0094222. eCollection 2014.
Brain activity during rest is spatially coherent over functional connectivity networks called resting-state networks. In resting-state functional magnetic resonance imaging, independent component analysis yields spatially distributed network representations reflecting distinct mental processes, such as intrinsic (default) or extrinsic (executive) attention, and sensory inhibition or excitation. These aspects can be related to different treatments or subjective experiences. Among these, exhaustion is a common psychological state induced by prolonged mental performance. Using repeated functional magnetic resonance imaging sessions and spatial independent component analysis, we explored the effect of several hours of sustained cognitive performances on the resting human brain. Resting-state functional magnetic resonance imaging was performed on the same healthy volunteers in two days, with and without, and before, during and after, an intensive psychological treatment (skill training and sustained practice with a flight simulator). After each scan, subjects rated their level of exhaustion and performed an N-back task to evaluate eventual decrease in cognitive performance. Spatial maps of selected resting-state network components were statistically evaluated across time points to detect possible changes induced by the sustained mental performance. The intensive treatment had a significant effect on exhaustion and effort ratings, but no effects on N-back performances. Significant changes in the most exhausted state were observed in the early visual processing and the anterior default mode networks (enhancement) and in the fronto-parietal executive networks (suppression), suggesting that mental exhaustion is associated with a more idling brain state and that internal attention processes are facilitated to the detriment of more extrinsic processes. The described application may inspire future indicators of the level of fatigue in the neural attention system.
静息状态下的大脑活动在称为静息态网络的功能连接网络上具有空间连贯性。在静息态功能磁共振成像中，独立成分分析产生反映不同心理过程的空间分布网络表征，如内在（默认）或外在（执行）注意力，以及感觉抑制或兴奋。这些方面可能与不同的治疗方法或主观体验有关。其中，疲惫是长时间脑力活动引起的一种常见心理状态。我们使用重复的功能磁共振成像会话和空间独立成分分析，探究了数小时持续认知活动对静息状态下人类大脑的影响。在两天内，对同一组健康志愿者进行静息态功能磁共振成像检查，一次是在进行强化心理治疗（技能训练和使用飞行模拟器持续练习）之前、期间和之后，另一次是在没有进行该治疗的情况下。每次扫描后，受试者对自己的疲惫程度进行评分，并执行n-back任务以评估认知表现是否最终下降。对选定的静息态网络成分的空间图谱在各个时间点进行统计评估，以检测持续脑力活动引起的可能变化。强化治疗对疲惫和努力程度评分有显著影响，但对n-back任务表现没有影响。在最疲惫状态下，早期视觉处理网络和前默认模式网络（增强）以及额顶叶执行网络（抑制）出现了显著变化，这表明精神疲惫与大脑更闲散的状态相关，并且内部注意力过程得到促进，而损害了更多的外在过程。所描述的应用可能会启发未来神经注意力系统疲劳程度指标的发展。
