Schofield Andrew J, Yates Timothy A
School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Perception. 2005;34(7):769-92. doi: 10.1068/p5294.
Recent studies of texture segmentation and second-order vision have proposed very similar models for the detection of orientation modulation and contrast modulation (OM and CM). From the similarity of the models it is tempting to assume that the two cues might be processed by a single generalised texture mechanism; however, recent results (Kingdom et al, 2003 Visual Neuroscience 2 65-76) have suggested that these cues are detected independently, or at least in a mechanism that is able to maintain an apparent independence between the cues. We tested new combinations of OM and CM and found that CM at 0.4 cycle deg(-1) facilitates the detection of OM at 0.2 cycle deg(-1) when the peaks of contrast align with the extremes of orientation. There is also some evidence of weak facilitation of CM by OM under the same conditions. Further, this facilitation can be predicted by filter--rectify--filter channels optimised for the detection of each cue, adding weight to the argument that texture cues are processed in a single generalised mechanism that nonetheless achieves cue independence or near-independence in many circumstances. We also found that the amount of suprathreshold masking produced by an orientation cue depends on the overall percept formed by that cue.
近期关于纹理分割和二阶视觉的研究针对方向调制和对比度调制（OM和CM）的检测提出了非常相似的模型。从这些模型的相似性来看，很容易假定这两种线索可能由单一的广义纹理机制进行处理；然而，近期的研究结果（Kingdom等人，《视觉神经科学》2003年第2期，65 - 76页）表明，这些线索是独立检测的，或者至少是在一种能够使线索之间保持明显独立性的机制中进行检测的。我们测试了OM和CM的新组合，发现当对比度峰值与方向极值对齐时，0.4周期度-1的CM会促进0.2周期度-1的OM的检测。在相同条件下，也有一些证据表明OM对CM有微弱的促进作用。此外，这种促进作用可以通过为检测每个线索而优化的滤波器-整流-滤波器通道来预测，这进一步支持了以下观点：纹理线索是在单一的广义机制中进行处理的，尽管如此，在许多情况下该机制仍能实现线索的独立或近乎独立。我们还发现，方向线索产生的阈上掩蔽量取决于该线索形成的整体感知。
