Lee S H, Blake R
Department of Psychology, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37240, USA.
Vision Res. 1999 Sep;39(18):3033-48. doi: 10.1016/s0042-6989(98)00333-2.
Observers can more easily detect correlated patterns of temporal contrast modulation within hybrid visual images composed of two components when those components are drawn from the same original picture (Blake, R., & Yang, Y. (1997). Proceedings of the National Academy of Science, 94, 7115-7119). To learn whether spatial phase is a mediating variable, we measured thresholds for detection of contrast modulation over time among component gratings while manipulating spatial phase among those components. In Experiment 1, observers more easily detected correlated contrast modulation when two component gratings were aligned in peaks-subtract phase. Experiment 2 showed that this phase-dependent detectability of synchronized contrast modulation is mediated by the phase-dependent, non-linear interaction among spatial frequency channels. The rigorous evaluation of several a priori reasonable hypotheses indicates that the phase-dependent detectability is not based on local spatial features such as local luminance, contrast or luminance gradient. Taken together, our results indicate that the spatial phase relationship and the temporal correlation of contrast modulation of two component gratings are both important for triggering facilitatory interaction between neural analyzers tuned to those gratings.
当混合视觉图像的两个组成部分取自同一原始图片时，观察者能更轻松地检测到其中由这两个部分构成的时间对比度调制的相关模式（布莱克，R.，& 杨，Y.（1997年）。《美国国家科学院院刊》，94，7115 - 7119）。为了探究空间相位是否为一个中介变量，我们在操纵这些组成部分之间的空间相位时，测量了观察者检测组成光栅随时间的对比度调制的阈值。在实验1中，当两个组成光栅以峰 - 减相位对齐时，观察者更容易检测到相关的对比度调制。实验2表明，这种同步对比度调制的相位依赖性可检测性是由空间频率通道之间的相位依赖性非线性相互作用介导的。对几个先验合理假设的严格评估表明，相位依赖性可检测性并非基于局部空间特征，如局部亮度、对比度或亮度梯度。综合来看，我们的结果表明，两个组成光栅的空间相位关系以及对比度调制的时间相关性对于触发调谐到这些光栅的神经分析器之间的促进性相互作用都很重要。
