Max Planck Institute for Biological Cybernetics, Department of Physiology of Cognitive Processes, Tuebingen, Germany.
Nat Neurosci. 2012 Jan 29;15(3):456-62, S1-2. doi: 10.1038/nn.3038.
Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories.
短期记忆需要多个大脑区域之间的通信，这些区域共同介导感觉信息的编码和维持。有人认为，振荡同步是皮质间通信的基础。然而，在视觉记忆过程中，远距离的皮质区域是否以及如何合作仍然难以捉摸。我们在猴子执行视觉短期记忆任务时，使用同时局部场电位（LFP）记录和单个单位活动（SUA），检查了视觉区 V4 和外侧前额叶皮层之间的神经相互作用。在记忆期间，我们观察到 LFP 的θ频率（3-9 Hz）之间的区域间相位同步增强，同时 SUA 与跨区域的θ振荡的相位锁定增加。此外，我们发现皮质间锁定的强度可以预测动物的行为表现。这表明θ频带同步协调 V4 和前额叶皮层之间的动作电位通信，这可能有助于维持视觉短期记忆。
