International Max Planck Research School for the Mechanisms of Mental Function and Dysfunction, University of Tübingen, Tübingen, Germany.
Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
Nat Commun. 2023 Apr 3;14(1):1858. doi: 10.1038/s41467-023-37613-7.
Intrinsic timescales characterize dynamics of endogenous fluctuations in neural activity. Variation of intrinsic timescales across the neocortex reflects functional specialization of cortical areas, but less is known about how intrinsic timescales change during cognitive tasks. We measured intrinsic timescales of local spiking activity within columns of area V4 in male monkeys performing spatial attention tasks. The ongoing spiking activity unfolded across at least two distinct timescales, fast and slow. The slow timescale increased when monkeys attended to the receptive fields location and correlated with reaction times. By evaluating predictions of several network models, we found that spatiotemporal correlations in V4 activity were best explained by the model in which multiple timescales arise from recurrent interactions shaped by spatially arranged connectivity, and attentional modulation of timescales results from an increase in the efficacy of recurrent interactions. Our results suggest that multiple timescales may arise from the spatial connectivity in the visual cortex and flexibly change with the cognitive state due to dynamic effective interactions between neurons.
固有时间尺度表征神经活动内源性波动的动力学。新皮层中固有时间尺度的变化反映了皮层区域的功能专业化，但对于固有时间尺度在认知任务期间如何变化知之甚少。我们在执行空间注意力任务的雄性猴子的 V4 区域的柱内测量了局部尖峰活动的固有时间尺度。持续的尖峰活动至少跨越两个不同的时间尺度展开，快和慢。当猴子注意到感受野位置时，慢时间尺度增加，并且与反应时间相关。通过评估几个网络模型的预测，我们发现 V4 活动的时空相关性最好由模型解释，其中多个时间尺度是由受空间排列连接性塑造的递归相互作用产生的，并且时间尺度的注意力调制是由于神经元之间的有效相互作用的增加而产生的。我们的结果表明，多个时间尺度可能来自视觉皮层的空间连接，并且由于神经元之间的动态有效相互作用，可能会根据认知状态灵活地变化。
