Modulation of gamma and alpha activity during a working memory task engaging the dorsal or ventral stream
Modulation of gamma and alpha activity during a working memory task engaging the dorsal or ventral stream
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DOI：
10.1523/jneurosci.5399-06.2007
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发表时间：
2007-03-21
影响因子：
5.3
通讯作者：
Jensen, Ole
中科院分区：
文献类型：
--
作者：
Jokisch, Daniel;Jensen, Ole
尽管在动物和人类身上进行了大量的实验工作，但振荡性大脑活动对工作记忆维持的实际作用仍然难以捉摸。伽马波段活动（30-100 Hz）被假设为反映神经元表征的维持或注意力需求的变化。关于后α活动（8-13 Hz），它是否反映了功能抑制或任务所需的神经元处理正在争论之中。本研究的目的是进一步阐明振荡脑活动在人类使用的工作记忆任务从事无论是背侧或腹侧视觉流的作用。我们使用脑磁图记录了执行延迟匹配样本任务的受试者的大脑活动。受试者被指示记住的身份或空间方向的短期提出的面孔。分析显示，更强的α功率周围的顶枕沟在保留的脸的身份（腹侧流）与保留的脸的方向（背侧流）。与此相反，成功地保留面部方向与增加伽玛功率在枕叶相对于面部身份的条件。我们建议，γ活动反映了实际的神经元维护的视觉表示，而α增加是功能抑制的结果。
Despite extensive experimental work in both animals and humans, the actual role of oscillatory brain activity for working memory maintenance remains elusive. Gamma band activity (30-100 Hz) has been hypothesized to reflect either the maintenance of neuronal representations or changing demands in attention. Regarding posterior alpha activity (8-13 Hz), it is under debate whether it reflects functional inhibition or neuronal processing required for the task. The aim of the present study was to further elucidate the role of oscillatory brain activity in humans using a working memory task engaging either the dorsal or ventral visual stream. We recorded brain activity using magnetoencephalography from subjects performing a delayed-match-to-sample task. Subjects were instructed to remember either the identity or the spatial orientation of shortly presented faces. The analysis revealed stronger alpha power around the parieto-occipital sulcus during retention of face identities (ventral stream) compared with the retention of face orientations (dorsal stream). In contrast, successful retention of face orientations was associated with an increase in gamma power in the occipital lobe relative to the face identity condition. We propose that gamma activity reflects the actual neuronal maintenance of visual representations, whereas the alpha increase is a result of functional inhibition.