Three stages and two systems of visual processing.
Three stages and two systems of visual processing.
复制标题
视觉处理的三个阶段和两个系统。
DOI：
10.1163/156856889x00112
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
G. Sperling
中科院分区：
文献类型：
--
作者：
G. Sperling
视觉处理的三个阶段决定了内部噪声如何出现在外部观察者面前：光适应、对比度增益控制和后感觉/决策阶段。暗噪声发生在适应之前，决定了适应黑暗的绝对阈值，并模仿静止的外部噪声。感觉噪声发生在黑暗适应之后，决定正弦光栅和类似刺激的对比度阈值，并模仿随平均亮度增加的外部噪声。后感觉噪声包括知觉、决策和记忆过程。它发生在对比度增益控制之后，并模拟随刺激对比度增加的外部噪声（即乘性噪声）。暗噪声和感觉噪声是频率特异性的，主要影响弱信号。只有感觉后噪声显著影响被刺激噪声掩盖的强信号的可分辨性；后感觉噪声在很宽的空间频率范围内具有恒定的功率，其中感觉噪声变化很大。两个平行的感知机制共同服务于人类的物体识别和运动感知：一个一阶线性（傅立叶）机制，直接从刺激亮度计算关系，一个二阶非线性（非傅立叶）校正机制，使用刺激对比度的绝对值（或功率）。当物体或运动由高空间频率（即波长相对于物体尺寸较小的纹理载波频率）定义时，高频受体的响应通过整流解调，以便在更高的处理水平上进行区分。校正牺牲了一阶区域的统计效率（抗噪声），以提高神经连通性和计算效率。
Three stages of visual processing determine how internal noise appears to an external observer: light adaptation, contrast gain control and a postsensory/decision stage. Dark noise occurs prior to adaptation, determines dark-adapted absolute thresholds and mimics stationary external noise. Sensory noise occurs after dark adaptation, determines contrast thresholds for sine gratings and similar stimuli, and mimics external noise that increases with mean luminance. Postsensory noise incorporates perceptual, decision and mnemonic processes. It occurs after contrast-gain control and mimics external noise that increases with stimulus contrast (i.e., multiplicative noise). Dark noise and sensory noise are frequency specific and primarily affect weak signals. Only postsensory noise significantly affects the discriminability of strong signals masked by stimulus noise; postsensory noise has constant power over a wide spatial frequency range in which sensory noise varies enormously. Two parallel perceptual regimes jointly serve human object recognition and motion perception: a first-order linear (Fourier) regime that computes relations directly from stimulus luminance, and a second-order nonlinear (nonFourier) rectifying regime that uses the absolute value (or power) of stimulus contrast. When objects or movements are defined by high spatial frequencies (i.e., texture carrier frequencies whose wavelengths are small compared to the object size), the responses of high-frequency receptors are demodulated by rectification to facilitate discrimination at the higher processing levels. Rectification sacrifices the statistical efficiency (noise resistance) of the first-order regime for efficiency of neural connectivity and computation.
影响因子：
--
作者：
LEGGE, GE;FOLEY, JM
通讯作者：
FOLEY, JM
DOI：
10.1364/josaa.4.000391
发表时间：
1987-02-01
影响因子：
1.9
作者：
LEGGE, GE;KERSTEN, D;BURGESS, AE
通讯作者：
BURGESS, AE