College of Optometry, The Ohio State University, Columbus, Ohio, United States.
Department of Psychological and Brain Sciences, University of Louisville, Louisville, Kentucky, United States.
Invest Ophthalmol Vis Sci. 2019 Jul 1;60(8):3178-3186. doi: 10.1167/iovs.18-26112.
We investigated how sensory eye dominance (SED) affects stereopsis when the half-images of random-dot-stereo stimuli had different interocular contrast.
We measured crossed and uncrossed stereo disparity thresholds and reaction time to seeing random-dot-stereograms with variable interocular contrast differences (ICD), where ICD = (log10 [CLE] - log10 [CRE]) = -0.4, -0.2, 0, 0.2, or 0.4 log unit. The mean contrast of the stimuli, (log10 [CLE] + log10 [CRE])/2, remained constant at 1.2 log unit to ensure that the measured effect was solely due to ICD. We also measured SED using, respectively, dichoptic horizontal sine wave gratings with different phases (revealing SEDcombo) and dichoptic vertical and horizontal gratings (revealing SEDinhibition).
Both measures of SEDinhibition and SEDcombo revealed the observers had the same eye as dominant although the magnitudes differed. The observers had lower stereo thresholds and shorter stereo reaction time on stimuli with unequal interocular contrast when the non-sensory-dominant eye viewed the higher contrast half-image, suggesting a stimulus-compensating effect. We then estimated the ICD of random-dot-stereo half-images (compensating stimuli) that would lead to minimum stereo threshold (SEDstereo-threshold) and reaction time (SEDstereo-RT) based on the stereo performance and ICD relationship, and found that they were significantly smaller than SEDinhibition and SEDcombo.
By linking SEDinhibition and SEDcombo with the effect of ICD on stereopsis, we provided further support for the notion that the stimulus-compensating effect is mediated by the interocular inhibitory and interocular gain control mechanisms. Furthermore, the interocular contrast for SEDstereo-threshold and SEDstereo-RT can be potentially applied for improving stereopsis in individuals with SED.
我们研究了当随机点立体刺激的半影具有不同的眼间对比度时，感觉眼优势（SED）如何影响立体视。
我们测量了交叉和非交叉立体视差阈值以及对具有不同眼间对比度差异（ICD）的随机点立体图像的反应时间，其中 ICD =（log10 [CLE] - log10 [CRE]）=-0.4、-0.2、0、0.2 或 0.4 log 单位。刺激的平均对比度（log10 [CLE] + log10 [CRE]）/2 保持在 1.2 log 单位不变，以确保测量的效果仅归因于 ICD。我们还分别使用具有不同相位的双眼水平正弦光栅（揭示 SEDcombo）和双眼垂直和水平光栅（揭示 SEDinhibition）来测量 SED。
SEDinhibition 和 SEDcombo 的两种测量均表明观察者的主导眼相同，尽管幅度不同。当非感觉主导眼观看更高对比度的半影时，观察者的立体阈值较低，立体反应时间较短，这表明存在刺激补偿效应。然后，我们根据立体性能和 ICD 关系估计了随机点立体半影（补偿刺激）的 ICD，以使立体阈值（SEDstereo-threshold）和反应时间（SEDstereo-RT）最小，并发现它们明显小于 SEDinhibition 和 SEDcombo。
通过将 SEDinhibition 和 SEDcombo 与 ICD 对立体视的影响联系起来，我们进一步支持了这样一种观点，即刺激补偿效应是由眼间抑制和眼间增益控制机制介导的。此外，SEDstereo-threshold 和 SEDstereo-RT 的眼间对比度可潜在地应用于改善 SED 个体的立体视。
