Burr D C, Morrone M C
Istituto di Neurofisiologia Del CNR, Pisa, Italy.
Vision Res. 1996 Jul;36(14):2069-78. doi: 10.1016/0042-6989(95)00282-0.
Previous work has shown that during saccadic eye movements, contrast sensitivity for low spatial frequency patterns modulated in luminance is selectively reduced by up to one logarithmic unit, while high spatial frequency patterns, and equiluminant patterns of all spatial frequencies are not suppressed at all [Burr et al. (1994). Nature, 371, 511-513]. Here we study the temporal characteristics for sensitivity to luminance and chromatic patterns during saccades, using the two-pulse summation technique. Sensitivity was measured for detecting two successive pulses as a function of stimulus-onset asynchrony, during normal viewing and during saccades. Impulse response functions were estimated from the summation data, for all conditions. For equiluminance, the functions were monophasic during normal viewing and saccades. For luminance modulation, the impulse response functions were di-phasic in both normal viewing and saccades. However, during saccades the impulse responses were faster in normal viewing. This result is consistent with the suggestion that saccadic suppression is mediated by contrast gain control mechanisms, known to occur in M-cells but not P-cells.
先前的研究表明，在扫视眼动过程中，亮度调制的低空间频率模式的对比敏感度会选择性降低多达一个对数单位，而高空间频率模式以及所有空间频率的等亮度模式则完全不会受到抑制[Burr等人（1994年）。《自然》，371，511 - 513]。在此，我们使用双脉冲求和技术研究扫视过程中对亮度和彩色模式敏感度的时间特性。在正常观看和扫视过程中，测量检测两个连续脉冲的敏感度，将其作为刺激起始异步性的函数。针对所有条件，从求和数据中估计脉冲响应函数。对于等亮度情况，在正常观看和扫视过程中，函数为单相。对于亮度调制，在正常观看和扫视过程中，脉冲响应函数均为双相。然而，在扫视过程中，正常观看时的脉冲响应更快。这一结果与以下观点一致，即扫视抑制是由对比度增益控制机制介导的，已知这种机制发生在M细胞而非P细胞中。
