Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, The Netherlands.
Hum Brain Mapp. 2010 Jan;31(1):26-35. doi: 10.1002/hbm.20842.
Successful working memory (WM) requires the engagement of relevant brain areas but possibly also the disengagement of irrelevant areas. We used magnetoencephalography (MEG) to elucidate the temporal dynamics of areas involved in a somatosensory WM task. We found an increase in gamma band activity in the primary and secondary somatosensory areas during encoding and retention, respectively. This was accompanied by an increase of alpha band activity over task-irrelevant regions including posterior and ipsilateral somatosensory cortex. Importantly, the alpha band increase was strongest during successful WM performance. Furthermore, we found frontal gamma band activity that correlated both with behavioral performance and the alpha band increase. We suggest that somatosensory gamma band activity reflects maintenance and attention-related components of WM operations, whereas alpha band activity reflects frontally controlled disengagement of task-irrelevant regions. Our results demonstrate that resource allocation involving the engagement of task-relevant and disengagement of task-irrelevant regions is needed for optimal task execution.
成功的工作记忆（WM）需要相关脑区的参与，但也可能需要无关脑区的脱离。我们使用脑磁图（MEG）来阐明参与躯体感觉 WM 任务的脑区的时间动态。我们发现，在编码和保持阶段，初级和次级躯体感觉区的伽马波段活动分别增加。这伴随着与任务无关的区域（包括后和同侧躯体感觉皮层）的 alpha 波段活动增加。重要的是，alpha 波段的增加在成功的 WM 表现期间最强。此外，我们发现与行为表现和 alpha 波段增加相关的额部伽马波段活动。我们认为，躯体感觉伽马波段活动反映了 WM 操作的维持和与注意力相关的成分，而 alpha 波段活动反映了额叶控制的无关任务区域的脱离。我们的结果表明，为了最佳地执行任务，需要涉及任务相关区域的参与和任务无关区域的脱离的资源分配。
