Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.
Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA.
Neuron. 2018 Jul 11;99(1):215-226.e4. doi: 10.1016/j.neuron.2018.05.026. Epub 2018 Jun 15.
Feature-based visual short-term memory is known to engage both sensory and association cortices. However, the extent of the participating circuit and the neural mechanisms underlying memory maintenance is still a matter of vigorous debate. To address these questions, we recorded neuronal activity from 42 cortical areas in monkeys performing a feature-based visual short-term memory task and an interleaved fixation task. We find that task-dependent differences in firing rates are widely distributed throughout the cortex, while stimulus-specific changes in firing rates are more restricted and hierarchically organized. We also show that microsaccades during the memory delay encode the stimuli held in memory and that units modulated by microsaccades are more likely to exhibit stimulus specificity, suggesting that eye movements contribute to visual short-term memory processes. These results support a framework in which most cortical areas, within a modality, contribute to mnemonic representations at timescales that increase along the cortical hierarchy.
基于特征的视觉短期记忆被认为同时涉及感觉和联合皮层。然而，参与的回路的范围以及记忆维持的神经机制仍然是激烈争论的问题。为了解决这些问题，我们在猴子执行基于特征的视觉短期记忆任务和穿插注视任务时，从 42 个皮质区记录神经元活动。我们发现，发射率的任务相关差异广泛分布在整个皮层，而发射率的刺激特异性变化则更为局限和层次化。我们还表明，记忆延迟期间的微扫视编码记忆中的刺激，并且受微扫视调制的单元更有可能表现出刺激特异性，这表明眼动有助于视觉短期记忆过程。这些结果支持了这样一种框架，即在沿皮质层次增加的时间尺度上，模态内的大多数皮质区有助于记忆表示。
