Abstract:
Recent studies suggest that binocular adding S+ and differencing S- channels play an important role in binocular vision. To test for such a role in the context of binocular contrast detection and binocular summation, we employed a surround masking paradigm consisting of a central target disk surrounded by a mask annulus. All stimuli were horizontally oriented 0.5c/d sinusoidal gratings. Correlated stimuli were identical in interocular spatial phase while anticorrelated stimuli were opposite in interocular spatial phase. There were four target conditions: monocular left eye, monocular right eye, binocular correlated and binocular anticorrelated, and three surround mask conditions: no surround, binocularly correlated and binocularly anticorrelated. We observed consistent elevation of detection thresholds for monocular and binocular targets across the two binocular surround mask conditions. In addition, we found an interaction between the type of surround and the type of binocular target: both detection and summation were relatively enhanced by surround masks and targets with opposite interocular phase relationships and reduced by surround masks and targets with the same interocular phase relationships. The data were reasonably well accounted for by a model of binocular combination termed MAX (S+S-), in which the decision variable is the probability summation of modeled S+ and S- channel responses, with a free parameter determining the relative gains of the two channels. Our results support the existence of two channels involved in binocular combination, S+ and S-, whose relative gains are adjustable by surround context.
摘要:
最近的研究表明,双眼添加S和差分S通道在双眼视觉中起着重要作用。为了在双眼对比检测和双眼求和的背景下测试这种作用,我们采用了一种环绕掩蔽范例,该范例由一个由掩模环围绕的中心目标盘组成。所有刺激均为水平取向的0.5c/d正弦光栅。相关刺激在眼间空间相位相同,而反相关刺激在眼间空间相位相反。有四个目标条件:单眼左眼,单眼右眼,双眼相关和双眼反相关,和三个环绕掩模条件:无环绕,双耳相关和双耳反相关。我们观察到在两种双目环绕面罩条件下单目和双目目标的检测阈值的一致升高。此外,我们发现了环绕物类型和双目目标类型之间的相互作用:具有相反眼间相位关系的环绕物掩模和目标相对增强了检测和求和,而具有相同眼间相位关系的环绕物掩模和目标相对增强了检测和求和。数据被称为MAX(S+S-)的双目组合模型合理地解释,其中决策变量是建模的S+和S-通道响应的概率总和,自由参数确定两个通道的相对增益。我们的结果支持存在两个通道参与双眼组合,S+和S-,其相对增益可通过环绕上下文调整。