Baker Daniel H, Wallis Stuart A, Georgeson Mark A, Meese Tim S
School of Life & Health Sciences, Aston University, Birmingham, UK.
Vision Res. 2012 Mar 1;56:1-9. doi: 10.1016/j.visres.2012.01.008. Epub 2012 Jan 24.
We studied the rules by which visual responses to luminous targets are combined across the two eyes. Previous work has found very different forms of binocular combination for targets defined by increments and by decrements of luminance, with decrement data implying a severe nonlinearity before binocular combination. We ask whether this difference is due to the luminance of the target, the luminance of the background, or the sign of the luminance excursion. We estimated the pre-binocular nonlinearity (power exponent) by fitting a computational model to ocular equibrightness matches. The severity of the nonlinearity had a monotonic dependence on the signed difference between target and background luminance. For dual targets, in which there was both a luminance increment and a luminance decrement (e.g. contrast), perception was governed largely by the decrement. The asymmetry in the nonlinearities derived from the subjective matching data made a clear prediction for visual performance: there should be more binocular summation for detecting luminance increments than for detecting luminance decrements. This prediction was confirmed by the results of a subsequent experiment. We discuss the relation between these results and luminance nonlinearities such as a logarithmic transform, as well as the involvement of contemporary model architectures of binocular vision.
我们研究了双眼对发光目标的视觉反应进行整合的规则。先前的研究发现，对于由亮度增加和亮度降低定义的目标，双眼整合的形式有很大不同，亮度降低的数据表明在双眼整合之前存在严重的非线性。我们探究这种差异是由于目标的亮度、背景的亮度还是亮度变化的符号。我们通过将计算模型拟合到双眼等亮度匹配来估计双眼前非线性（幂指数）。非线性的严重程度与目标和背景亮度之间的符号差呈单调依赖关系。对于既有亮度增加又有亮度降低（例如对比度）的双目标，感知主要由亮度降低主导。从主观匹配数据得出的非线性中的不对称性对视觉表现做出了明确预测：检测亮度增加时的双眼总和应比检测亮度降低时更多。后续实验结果证实了这一预测。我们讨论了这些结果与诸如对数变换等亮度非线性之间的关系，以及当代双眼视觉模型架构的参与情况。
