Departments of Neuroscience and Brain and Cognitive Sciences, Del Monte Institute for Neuroscience, and Center for Visual Science, University of Rochester, Rochester, New York 14642, USA; email:
Annu Rev Vis Sci. 2020 Sep 15;6:313-334. doi: 10.1146/annurev-vision-121219-081716. Epub 2020 Jun 17.
The physiological response properties of neurons in the visual system are inherited mainly from feedforward inputs. Interestingly, feedback inputs often outnumber feedforward inputs. Although they are numerous, feedback connections are weaker, slower, and considered to be modulatory, in contrast to fast, high-efficacy feedforward connections. Accordingly, the functional role of feedback in visual processing has remained a fundamental mystery in vision science. At the core of this mystery are questions about whether feedback circuits regulate spatial receptive field properties versus temporal responses among target neurons, or whether feedback serves a more global role in arousal or attention. These proposed functions are not mutually exclusive, and there is compelling evidence to support multiple functional roles for feedback. In this review, the role of feedback in vision will be explored mainly from the perspective of corticothalamic feedback. Further generalized principles of feedback applicable to corticocortical connections will also be considered.
视觉系统中神经元的生理反应特性主要来自于前馈输入。有趣的是，反馈输入通常比前馈输入多。尽管它们数量众多，但与快速、高效的前馈连接相比，反馈连接较弱、较慢，被认为是调节性的。因此，反馈在视觉处理中的功能作用一直是视觉科学中的一个基本谜团。这个谜团的核心问题是，反馈回路是调节目标神经元的空间感受野特性还是时间响应，还是反馈在觉醒或注意力方面起更全局的作用。这些提出的功能并非相互排斥，并且有强有力的证据支持反馈的多种功能作用。在这篇综述中，将主要从皮层-丘脑反馈的角度来探讨反馈在视觉中的作用。还将考虑适用于皮质-皮质连接的反馈的一般化原则。
