小柯机器人

英国伦敦大学学院、瑞士巴塞尔大学Ivan Voitov团队揭示皮层反馈回路绑定工作记忆的分布式表征。2022年7月27日，国际知名学术期刊《自然》发表了这一成果。

他们描述了小鼠视觉工作记忆的神经实现，在延迟的不匹配样本任务和不需要工作记忆但具有相同刺激、运动和奖励统计的简单辨别任务之间交替。瞬时光遗传学失活表明，新皮质的分布区域是选择性地维持工作记忆所必需的。延迟期间视觉区 AM 和运动前区 M2 的群体活动由有序的低维动力学主导，然而，这些活动与工作记忆无关。相反，工作记忆表征嵌入在高维人口活动中，存在于两个皮层区域，在整个刺激间延迟期间持续存在，并预测工作记忆任务期间的行为反应。

为了测试工作记忆的分布性质是否依赖于皮层区域之间的相互作用 ，他们在记录从另一个皮层区域（AM 或 M2）接收到的反馈时使一个皮层区域（AM 或 M2）静音。任一区域的瞬时失活导致工作记忆的区域间通信选择性中断。因此，相互连接的皮层区域维持了工作记忆的绑定高维表示。

据悉，工作记忆——大脑将信息内化并灵活使用它来指导行为的能力——是认知的重要组成部分。尽管已在多个大脑区域观察到与工作记忆相关的活动，但神经群体如何实际代表工作记忆以及维持该活动的机制仍不清楚。

附：英文原文

Title: Cortical feedback loops bind distributed representations of working memory

Author: Voitov, Ivan, Mrsic-Flogel, Thomas D.

Issue&Volume: 2022-07-27

Abstract: Working memory—the brain’s ability to internalize information and use it flexibly to guide behaviour—is an essential component of cognition. Although activity related to working memory has been observed in several brain regions1,2,3, how neural populations actually represent working memory4,5,6,7 and the mechanisms by which this activity is maintained8,9,10,11,12 remain unclear13,14,15. Here we describe the neural implementation of visual working memory in mice alternating between a delayed non-match-to-sample task and a simple discrimination task that does not require working memory but has identical stimulus, movement and reward statistics. Transient optogenetic inactivations revealed that distributed areas of the neocortex were required selectively for the maintenance of working memory. Population activity in visual area AM and premotor area M2 during the delay period was dominated by orderly low-dimensional dynamics16,17 that were, however, independent of working memory. Instead, working memory representations were embedded in high-dimensional population activity, present in both cortical areas, persisted throughout the inter-stimulus delay period, and predicted behavioural responses during the working memory task. To test whether the distributed nature of working memory was dependent on reciprocal interactions between cortical regions18,19,20, we silenced one cortical area (AM or M2) while recording the feedback it received from the other. Transient inactivation of either area led to the selective disruption of inter-areal communication of working memory. Therefore, reciprocally interconnected cortical areas maintain bound high-dimensional representations of working memory.

DOI: 10.1038/s41586-022-05014-3

Source: https://www.nature.com/articles/s41586-022-05014-3

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
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