Department of Psychology, Ludwig-Maximilians-Universität München, Leopoldstr. 13, 80802 Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany.
Department of Psychology, Ludwig-Maximilians-Universität München, Leopoldstr. 13, 80802 Munich, Germany; School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Neuroimage. 2021 Jul 15;235:117971. doi: 10.1016/j.neuroimage.2021.117971. Epub 2021 Apr 8.
Visual perception is influenced by our expectancies about incoming sensory information. It is assumed that mental templates of expected sensory input are created and compared to actual input, which can be matching or not. When such mental templates are held in working memory, cross-frequency phase synchronization (CFS) between theta and gamma band activity has been proposed to serve matching processes between prediction and sensation. We investigated how this is affected by the number of activated templates that could be matched by comparing conditions where participants had to keep either one or multiple templates in mind for successful visual search. We found a transient CFS between EEG theta and gamma activity in an early time window around 150 ms after search display presentation, in right hemispheric parietal cortex. Our results suggest that for single template conditions, stronger transient theta-gamma CFS at posterior sites contralateral to target presentation can be observed than for multiple templates. This can be interpreted as evidence to the idea of sequential attentional templates. But mainly, it is understood in line with previous theoretical accounts strongly arguing for transient synchronization between posterior theta and gamma phase as a neural correlate of matching incoming sensory information with contents from working memory and as evidence for limitations in memory matching during multiple template search.
视觉感知受到我们对传入感觉信息的期望的影响。人们假设，预期感觉输入的心理模板被创建，并与实际输入进行比较，这可能匹配也可能不匹配。当这些心理模板在工作记忆中时，已经提出了theta 和 gamma 频带活动之间的跨频相位同步（CFS），以服务于预测和感觉之间的匹配过程。我们研究了当参与者必须记住一个或多个模板以成功进行视觉搜索时，这种情况会受到可以匹配的激活模板数量的影响。我们发现，在搜索显示呈现后约 150 毫秒的早期时间窗口中，在右侧顶叶皮层中存在 EEG theta 和 gamma 活动之间的瞬态 CFS。我们的结果表明，对于单个模板条件，可以观察到与目标呈现对侧的后部位的更强的瞬态 theta-gamma CFS，而对于多个模板则不然。这可以解释为顺序注意模板的想法的证据。但主要是，它与之前的理论解释一致，强烈主张后theta 和 gamma 相位之间的瞬态同步作为将传入感觉信息与工作记忆内容相匹配的神经相关物，并作为在多个模板搜索期间记忆匹配受限的证据。
