视觉适应及其神经机制

Visual Adaptation and Its Neural Mechanisms

视适应使得视觉系统可以连续地根据外界环境的变化做出调整,改善了对世界的感知。研究提示,适应影响了对许多基本的视觉属性的加工,诸如亮度、对比度、运动、颜色等,也包括对复杂的刺激如面孔等。视适应发生于视觉加工流的多个阶段,从视网膜到初级视觉皮层以及之后的脑区(例如纹外皮层,梭状回面孔区)。关于视适应的机制解释,已从早期的神经元反应疲劳解释发展成当今更流行的标准化模型理论等。最近的适应研究证明,视觉适应由时间尺度上快慢不同的多重机制控制,这被认为赋予了视觉系统有效应对环境中不同时间尺度的变化的能力。

Visual adaptation enables the visual system to continuously adjust to the environment, improving the perception of the world. It has been found that adaptation affects the processing of many fundamental visual qualities, such as luminance, contrast, motion, color, etc., as well as more complex stimuli, e.g. faces. Adaptation occurs at multiple stages along the visual processing stream, from retina to primary visual cortex and beyond （e.g. extrastriate cortex, fusiform face areas）. The mechanical interpretation of visual adaptation has been developed from the earlier account of neural fatigue to the nowadays more popular normalization models. Recent adaptation studies demonstrate that visual adaptation is controlled by multiple distinct mechanisms that operate at differing timescales, which may endow the visual system with the ability to accommodate environmental changes over different timescales.