Preserved gain control for luminance contrast during binocular rivalry suppression.
Preserved gain control for luminance contrast during binocular rivalry suppression.
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在双眼竞争抑制期间保留亮度对比度的增益控制。
DOI：
10.1016/j.visres.2004.07.011
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Blake,Randolph
中科院分区：
文献类型：
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作者：
Watanabe,Katsumi;Paik,Young;Blake,Randolph
双目竞争提高了对比度增加的阈值，用于检测呈现给受抑制眼睛的瞬时刺激，而在优势期间测量的阈值与在单眼观看期间测量的阈值相同(例如[Wales，R.，&Fox，R.(1970)。在双眼竞争抑制过程中增加检测阈值。知觉与心理物理学，8，90-94])。众所周知，对比度增量阈值取决于基准(基座)对比度。在高对比度下，增量阈值随着基座对比度的增加而增加，反映了具有S形非线性的增益控制。我们研究了这种增益控制机制在双目竞争中是如何运作的(即，在有或没有感觉到底座面具的情况下)。受试者分别观看水平正弦波栅格(稳定基座)和径向棋盘。当光栅达到预先指定的现象状态(显性或抑制)时，受试者启动相同空间频率的对比度增量的瞬时呈现(500毫秒高斯脉冲)。脉搏出现在底座的上半部分或下半部分。受试者指出底座的哪一半含有脉搏。使用阶梯法测量不同基座对比度的对比度增加阈值，在显性和抑制过程中产生阈值与对比度(TVC)函数。在抑制过程中测得的阈值可靠地较高，但TVC功能的上升斜率在优势和抑制之间没有显著差异(即TVC功能的恒定上移)。一项对照实验表明，优势时的TVC功能与非竞争、单眼观看时的功能相同。显然，用于瞬时亮度增量的对比度增益控制不需要感知基座对比度。
Binocular rivalry elevates contrast increment thresholds for the detection of a transient stimulus presented to the suppressed eye, while thresholds measured during dominance are identical to those during monocular viewing (e.g. [Wales, R., & Fox, R. (1970). Increment detection thresholds during binocular rivalry suppression. Perception and Psychophysics, 8, 90–94]). It is well established that contrast increment thresholds depend on reference (pedestal) contrast. With high contrasts, increment thresholds increase with pedestal contrast, reflecting a gain control with sigmoidal non-linearity. We examined how this gain control mechanism operates during binocular rivalry (i.e., with and without perception of a pedestal mask). Subjects viewed a horizontal sine-wave grating (steady pedestal) and a radial checkerboard dichoptically. When the grating achieved a pre-specified phenomenal state (dominance or suppressed), subjects initiated the transient presentation (500-ms Gaussian pulse) of a contrast increment of the same spatial frequency. The pulse appeared in either the upper or lower half of the pedestal. Subjects indicated which half of the pedestal contained the pulse. Contrast increment thresholds were measured using a staircase method with various pedestal contrasts, which yielded threshold versus contrast (TvC) functions during dominance and suppression. The measured thresholds were reliably higher during suppression, but the rising slopes of TvC functions did not differ significantly between dominance and suppression (i.e., constant upward shift of TvC function). A control experiment demonstrated that the TvC function during dominance was identical to that during non-rivalry, monocular viewing. Evidently, the contrast gain control for transient luminance increment does not require the perception of pedestal contrast.