S-cone signals to temporal OFF-channels: asymmetrical connections to postreceptoral chromatic mechanisms.
S-cone signals to temporal OFF-channels: asymmetrical connections to postreceptoral chromatic mechanisms.
复制标题
S 锥体信号到时间关闭通道：与感受器后色彩机制的不对称连接。
DOI：
10.1016/s0042-6989(97)00460-4
复制
发表时间：
1999
期刊：
影响因子：
1.8
通讯作者：
Werner,JS
中科院分区：
文献类型：
--
作者：
Shinomori,K;Spillmann,L;Werner,JS
心理物理测试的S-锥贡献的时间ON和OFF通道进行。检测阈值的S-锥调制的测量与两种测试刺激CRT上提出的：一个快速上的测试和一个快速关闭的测试，假设被检测到的时间ON和OFF通道的差异，分别。通过适应Maxwellian视图中呈现的1 Hz单色（420、440、450、540或650 nm，在单独的会话中）闪烁5 min来分离S锥相关的ON和OFF时间响应。在距离中心注视点1.0°的四个象限中的一个象限中，呈现圆形测试刺激，具有双时间轮廓和高斯空间锥度，持续1 s。一个四个替代的强制选择的方法结合双阶梯程序被用来确定在同一会话中的ON和OFF阈值。适应后，阈值升高更大，如果测试刺激的极性是相同的极性的闪烁适应，与S-锥的单独的ON和OFF响应一致。然而，只有当适应刺激出现蓝色和一点红色时，才能获得这种不对称的图案。当适应闪烁有一个明确的红色色调的成分，阈值的提高并不依赖于极性的最大刺激。这些结果是一致的模型，其中关闭信号来自S-锥维持postreceptoral机制信号发红，但不是由postreceptoral彩色机制信号蓝色。
Psychophysical tests of S-cone contributions to temporal ON- and OFF-channels were conducted. Detection thresholds for S-cone modulation were measured with two kinds of test stimuli presented on a CRT: a rapid-on sawtooth test and a rapid-off sawtooth test, assumed to be detected differentially by temporal ON- and OFF-channels, respectively. S-cone related ON- and OFF-temporal responses were separated by adapting for 5 min to 1 Hz monochromatic (420, 440, 450, 540, or 650 nm in separate sessions) sawtooth flicker presented in Maxwellian view. Circular test stimuli, with a sawtooth temporal profile and a Gaussian spatial taper, were presented for 1 s in one of four quadrants 1.0° from a central fixation point. A four-alternative forced-choice method combined with a double-staircase procedure was used to determine ON- and OFF-thresholds in the same session. Following adaptation, the threshold elevation was greater if the polarity of the test stimulus was the same as the polarity of the sawtooth adaptation flicker, consistent with separate ON- and OFF-responses from S-cones. This asymmetrical pattern was obtained, however, only when the adaptation stimuli appeared blue with a little redness. When the adaptation flicker had a clear reddish hue component, the threshold elevation did not depend on the polarity of the sawtooth test stimuli. These results are consistent with a model in which OFF-signals originating from S-cones are maintained by a postreceptoral mechanism signaling redness, but not by a postreceptoral chromatic mechanism signaling blueness.