Neural locus of color afterimages.
Neural locus of color afterimages.
复制标题
神经颜色的含量。
DOI：
10.1016/j.cub.2011.12.021
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发表时间：
2012-02-07
期刊：
影响因子：
--
通讯作者：
Lee B
中科院分区：
文献类型：
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作者：
Zaidi Q;Ennis R;Cao D;Lee B
在注视一个彩色图案后，当刺激被移除时，观察者看到一个互补色的类似图案。后像在反驳视觉射线从眼睛发出的理论，证明眼间的相互作用，以及揭示双眼视觉独立于眼睛运动方面都很重要。残像在探索选择性注意、填充和意识方面也被证明是非常宝贵的。彩色后像的生理机制从视锥色素的漂白到皮质适应，但直接的神经测量尚未报道。我们引入了一个随时间变化的方法，唤起后的图像，它提供了精确的测量适应和视觉感知和神经反应之间的直接联系。然后，我们使用在体内的电生理记录表明，所有三类灵长类动物视网膜神经节细胞表现出减法适应延长刺激，与慢得多的时间常数比预期的光感受器。在刺激停止时，神经节细胞产生反弹反应，可以为后来的神经元提供后像信号。我们的研究结果表明，后像信号在视网膜中产生，但可能会像其他视网膜信号的皮质过程进行修改，因此，皮质产生的彩色后像的证据是可以解释的时空因素，适用于所有的信号。
After fixating on a colored pattern, observers see a similar pattern in complementary colors when the stimulus is removed. Afterimages were important in disproving the theory that visual rays emanate from the eye, in demonstrating inter-ocular interactions, and in revealing the independence of binocular-vision from eye-movements. Afterimages also prove invaluable in exploring selective attention, filling-in, and consciousness. Proposed physiological mechanisms for color afterimages range from bleaching of cone photo-pigments to cortical adaptation, but direct neural measurements have not been reported. We introduce a time-varying method for evoking after-images, which provides precise measurements of adaptation and a direct link between visual percepts and neural responses. We then use in vivo electrophysiological recordings to show that all three classes of primate retinal ganglion cells exhibit subtractive adaptation to prolonged stimuli, with much slower time-constants than those expected of photoreceptors. At the cessation of the stimulus, ganglion cells generate rebound responses that can provide afterimage signals for later neurons. Our results indicate that afterimage signals are generated in the retina, but may be modified like other retinal signals by cortical processes, so that evidence presented for cortical generation of color afterimages is explainable by spatio-temporal factors that apply to all signals.