Krause Matthew R, Pack Christopher C
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
Vision Res. 2014 Nov;104:36-46. doi: 10.1016/j.visres.2014.10.006. Epub 2014 Nov 3.
Contextual modulation is observed throughout the visual system, using techniques ranging from single-neuron recordings to behavioral experiments. Its role in generating feature selectivity within the retina and primary visual cortex has been extensively described in the literature. Here, we describe how similar computations can also elaborate feature selectivity in the extrastriate areas of both the dorsal and ventral streams of the primate visual system. We discuss recent work that makes use of normalization models to test specific roles for contextual modulation in visual cortex function. We suggest that contextual modulation renders neuronal populations more selective for naturalistic stimuli. Specifically, we discuss contextual modulation's role in processing optic flow in areas MT and MST and for representing naturally occurring curvature and contours in areas V4 and IT. We also describe how the circuitry that supports contextual modulation is robust to variations in overall input levels. Finally, we describe how this theory relates to other hypothesized roles for contextual modulation.
在整个视觉系统中都观察到了上下文调制，使用的技术范围从单神经元记录到行为实验。其在视网膜和初级视觉皮层内产生特征选择性方面的作用在文献中已有广泛描述。在这里，我们描述了类似的计算如何也能在灵长类视觉系统背侧和腹侧流的纹外区域细化特征选择性。我们讨论了最近利用归一化模型来测试上下文调制在视觉皮层功能中的特定作用的工作。我们认为上下文调制使神经元群体对自然主义刺激更具选择性。具体来说，我们讨论了上下文调制在MT和MST区域处理光流以及在V4和IT区域表示自然出现的曲率和轮廓方面的作用。我们还描述了支持上下文调制的电路如何对整体输入水平的变化具有鲁棒性。最后，我们描述了该理论与上下文调制的其他假设作用的关系。
