IMPULSE-RESPONSE FUNCTIONS FOR CHROMATIC AND ACHROMATIC STIMULI
IMPULSE-RESPONSE FUNCTIONS FOR CHROMATIC AND ACHROMATIC STIMULI
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DOI：
10.1364/josaa.10.001706
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发表时间：
1993-08-01
影响因子：
1.9
通讯作者：
MORRONE, MC
中科院分区：
文献类型：
--
作者：
BURR, DC;MORRONE, MC
测量了用于检测在可变起始时间连续显示的短暂闪光刺激对的持续时间。刺激是1周期/度垂直正弦光栅，在亮度（黄-黑）或颜色（红-绿）上调制。连续的呈现是相同的对比度（正）或相反的对比度（负），产生四个单独的总和曲线：颜色和亮度的正和负总和。正曲线和负曲线都遵循亮度比颜色更短的时间过程，这意味着阈值响应更快。为了从求和数据计算脉冲响应函数，我们假设来自两个连续刺激的神经脉冲响应在阈值处线性求和，阈值由组合脉冲响应随时间的概率求和确定，并且脉冲响应可以由具有四个自由参数的指数阻尼调频正弦函数描述。亮度和颜色的预测脉冲响应是完全不同的，是双相的亮度和双相的颜色。这些功能的傅立叶变换产生的假设的视觉检测器的振幅和相位函数的估计：振幅函数预测以及反相光栅（作为时间频率的函数）的亮度和彩色刺激的对比敏感度。
Thresholds were measured for detecting pairs of briefly flashed stimuli displayed successively at variable onset asynchronies. The stimuli were 1 cycle/deg vertical sinusoidal gratings, modulated either in luminance (Yellow-black) or in color (red-green). The successive presentations were either of the same contrast (positive) or of opposite contrast (negative), yielding four separate summation curves: positive and negative summation for color and for luminance. Both the positive and the negative curves followed a shorter time course for luminance than for color, implying a faster response at threshold. To calculate impulse response functions from the summation data, we assumed that the neural impulse response from two successive stimuli sum linearly at threshold, that thresholds are determined by probability summation of the combined impulse response over time, and that the impulse response can be described by an exponentially damped frequency-modulated sinusoidal function with four free parameters. The predicted impulse responses for luminance and for color are quite different, being biphasic for luminance and monophasic for color. Fourier transform of these functions yielded estimates of the amplitude and the phase functions of hypothetical visual detectors: the amplitude functions predicted well the contrast sensitivity of counterphased gratings (as a function of temporal frequency) both for luminance and for chromatic stimuli.