Roelfsema P R, Engel A K, König P, Singer W
Max-Planck-Institute for Brain Research, Frankfurt, Germany.
Nature. 1997 Jan 9;385(6612):157-61. doi: 10.1038/385157a0.
Information processing in the cerebral cortex invariably involves the activation of millions of neurons that are widely distributed over its various areas. These distributed activity patterns need to be integrated into coherent representational states. A candidate mechanism for the integration and coordination of neuronal activity between different brain regions is synchronization on a fine temporal scale. In the visual cortex, synchronization occurs selectively between the responses of neurons that represent related features and that need to be integrated for the generation of coherent percepts; neurons in other areas of the cerebral cortex also synchronize their discharges. However, little is known about the patterns and the behavioural correlates of synchrony among widely separated cortical regions. Here we report that synchronization occurs between areas of the visual and parietal cortex, and between areas of the parietal and motor cortex, in the awake cat. When cats responded to a sudden change of a visual pattern, neuronal activity in cortical areas exhibited synchrony without time lags; this synchrony was particularly strong between areas subserving related functions. During reward and inter-trial episodes, zero-time-lag synchrony was lost and replaced by interactions exhibiting large and unsystematic time lags.
大脑皮层中的信息处理总是涉及数百万个广泛分布在其各个区域的神经元的激活。这些分布式活动模式需要被整合到连贯的表征状态中。一种用于整合和协调不同脑区之间神经元活动的候选机制是在精细的时间尺度上实现同步。在视觉皮层中，同步选择性地发生在代表相关特征且需要整合以产生连贯感知的神经元反应之间；大脑皮层其他区域的神经元也会使其放电同步。然而，对于广泛分离的皮层区域之间同步的模式及其行为相关性却知之甚少。在此我们报告，在清醒的猫中，视觉皮层和顶叶皮层区域之间以及顶叶皮层和运动皮层区域之间会发生同步。当猫对视觉模式的突然变化做出反应时，皮层区域的神经元活动表现出无时间滞后的同步；这种同步在承担相关功能的区域之间尤为强烈。在奖励和试验间期，零时滞同步消失，取而代之的是表现出大的且无系统时间滞后的相互作用。
