Brain and Cognitive Sciences, University of Rochester, Rochester, New York, 14627, USA.
Center for Visual Science, University of Rochester, Rochester, New York, 14620, USA.
Eur J Neurosci. 2023 May;57(9):1561-1576. doi: 10.1111/ejn.15964. Epub 2023 Apr 4.
Neurons in the primate middle temporal (MT) area signal information about visual motion and work together with the lateral prefrontal cortex (LPFC) to support memory-guided comparisons of visual motion direction. These areas are reciprocally connected, and both contain neurons that signal visual motion direction in the strength of their responses. Previously, LPFC was shown to display marked changes in stimulus coding with altered task demands, including changes in selectivity for motion direction, trial-to-trial variability in responses and comparison effects. Since MT and LPFC are directly interconnected, we sought to determine if MT neurons display similar dependence on task demands. We found that active participation in a motion direction comparison task affected both sensory and nonsensory activity in MT neurons. In fact, neurons that became less selective for motion direction during the active task showed increased signalling for cognitive aspects of the task. This heterogeneity in neural modification with heightened task demands suggests a division of labour in MT, whereby sensory and cognitive signals are both heightened in different subpopulations of neurons.
灵长类动物中颞中（MT）区的神经元传递有关视觉运动的信息，它们与外侧前额叶皮层（LPFC）协同工作，以支持记忆引导的视觉运动方向比较。这些区域是相互连接的，两者都包含响应强度信号视觉运动方向的神经元。以前的研究表明，LPFC 在改变任务要求时显示出明显的刺激编码变化，包括对运动方向的选择性变化、反应的试验间变异性和比较效应。由于 MT 和 LPFC 直接相互连接，我们试图确定 MT 神经元是否表现出对任务需求的类似依赖性。我们发现，主动参与运动方向比较任务会影响 MT 神经元的感觉和非感觉活动。事实上，在活跃任务中对运动方向的选择性降低的神经元对任务的认知方面表现出信号增强。随着任务需求的增加，神经修饰的这种异质性表明 MT 中的劳动分工，其中在不同的神经元亚群中都增强了感觉和认知信号。
