Laboratory of Sensorimotor Research, National Eye Institute, NIH, Bethesda, MD, USA.
Brown-NIH Neuroscience Graduate Partnership Program, Providence, RI, USA.
Nat Neurosci. 2018 Apr;21(4):598-606. doi: 10.1038/s41593-018-0089-1. Epub 2018 Feb 26.
The variable responses of sensory neurons tend to be weakly correlated (spike-count correlation, r). This is widely thought to reflect noise in shared afferents, in which case r can limit the reliability of sensory coding. However, it could also be due to feedback from higher-order brain regions. Currently, the relative contributions of these sources are unknown. We addressed this by recording from populations of V1 neurons in macaques performing different discrimination tasks involving the same visual input. We found that the structure of r (the way r varied with neuronal stimulus preference) changed systematically with task instruction. Therefore, even at the earliest stage in the cortical visual hierarchy, r structure during task performance primarily reflects feedback dynamics. Consequently, previous proposals for how r constrains sensory processing need not apply. Furthermore, we show that correlations between the activity of single neurons and choice depend on feedback engaged by the task.
感觉神经元的可变响应往往相关性较弱（尖峰计数相关，r）。这被广泛认为反映了共同传入的噪声，在这种情况下，r 可以限制感觉编码的可靠性。然而，这也可能是由于来自大脑更高区域的反馈。目前，这些来源的相对贡献尚不清楚。我们通过记录执行涉及相同视觉输入的不同辨别任务的猕猴 V1 神经元群体来解决这个问题。我们发现 r 的结构（r 随神经元刺激偏好变化的方式）随着任务指令而系统地变化。因此，即使在皮质视觉层次结构的最早阶段，任务执行过程中的 r 结构主要反映了反馈动力学。因此，以前关于 r 如何限制感觉处理的建议可能并不适用。此外，我们还表明，单个神经元活动与选择之间的相关性取决于任务所涉及的反馈。
