Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain
Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain
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DOI：
10.1364/josaa.14.002477
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发表时间：
1997-09-01
影响因子：
1.9
通讯作者：
Smith, VC
中科院分区：
文献类型：
--
作者：
Pokorny, J;Smith, VC
生理数据揭示了大细胞（MC）和小细胞（PC）通路的特征对比度增益和时间整合特征。这项研究的目标是找到这些特征的心理物理相关性。通过刺激环绕显示器收集心理物理强制选择、亮度基座辨别数据。 2.05 度的四方形刺激阵列在更大的 115-Td 环绕中从 73 到 182 个 troland (Td) 变化。当刺激阵列短暂脉冲时，辨别阈值在周围视网膜照度处显示最小值，当刺激阵列相对于周围递增或递减时，辨别阈值以 V 形增加。当刺激阵列在恒定的 115-Td 环绕内连续呈现为稳定基座时，辨别阈值随着刺激阵列视网膜照度单调增加，遵循统一斜率。曝光持续时间变化表明脉冲增量和减量的时间总和比稳定基座条件延长到更长的持续时间。脉冲中等大小对比度步骤的辨别阈值显示了 PC 通路的对比度增益特征和时间特征。稳定基座范式的辨别阈值显示了 MC 通路的时间特征。刺激阵列的小基座台阶与稳定基座的区分阈值显示了 MC 通路的对比度增益特征。数据表明，两种通路的适应时空控制存在差异：MC 通路局部适应刺激阵列，而 PC 通路几乎没有显示局部适应的证据。实验表明，MC 和 PC 通路处理的特征特征可以通过使用心理物理学程序来证明。 (C) 1997 年美国光学学会。
Physiological data have revealed characteristic contrast gain and temporal integration signatures of the magnocellular (MC) and the parvocellular (PC) pathways. The goal in this study was to find psychophysical correlates of these signatures. Psychophysical forced-choice, luminance pedestal discrimination data were collected with a stimulus-surround display. A 2.05 degrees four-square stimulus array was varied from 73 to 182 trolands (Td) in a larger 115-Td surround. When the stimulus array was pulsed briefly, discrimination thresholds showed a minimum at the surround retinal illuminance, increasing in a V shape when the stimulus array was incremental or decremental to the surround. When the stimulus array was presented continuously as a steady pedestal within the constant 115-Td surround, discrimination thresholds increased monotonically with stimulus array retinal illuminance, obeying a slope of unity. Exposure duration variation showed temporal summation to extend to longer durations for the pulse increments and decrements than for the steady pedestal condition. Discrimination thresholds for pulsed medium-sized contrast steps showed the contrast gain signature and the temporal signature of the PC pathway. Discrimination thresholds for the steady pedestal paradigm showed the temporal signature of the MC pathway. Discrimination thresholds for small pedestal steps of the stimulus array from a steady pedestal showed the contrast gain signature of the MC pathway. The data suggested a difference in the spatiotemporal control of adaptation of the two pathways: The MC pathway adapted locally to the stimulus array, while the PC pathway showed little evidence of local adaptation. The experiments show that characteristic signatures of MC-and PC-pathway processing can be demonstrated by use of psychophysical procedures. (C) 1997 Optical Society of America.