Cruickshank Alice G, Schofield Andrew J
School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Spat Vis. 2005;18(4):379-97. doi: 10.1163/1568568054389624.
Second-order cues are visual stimuli that are detectable by human observers, without eliciting a peak in Fourier energy that corresponds to their perceptual properties. The most commonly studied exemplars of second-order cues are those defined by modulation of local contrast (CM). It is widely accepted that such cues are initially detected separately from first-order, luminance modulated (LM), cues. However, after-effects have been shown to transfer between first- and second-order cues (LM and CM, respectively). This suggests the existence of a late link in the mechanisms that subserve their processing. To extend the investigation of the mechanisms for processing second-order cues we consider cues defined by modulations in local orientation (OM). Using a tilt-after-effect (TAE) paradigm, we found partial transfer of adaptation between LM and OM cues, confirming the presence of a link between first and second-order cues. Furthermore, we found a partial transfer of TAE between OM and CM cues. These results suggest that, at or before the site of adaptation, information from all visual cues is combined. However, as transfer of adaptation is below 100% in all cases, this is only a partial integration of information.
二阶线索是人类观察者能够检测到的视觉刺激，在傅里叶能量中不会引发与它们的感知特性相对应的峰值。二阶线索最常被研究的示例是由局部对比度调制（CM）定义的那些。人们普遍认为，此类线索最初是与一阶亮度调制（LM）线索分开检测的。然而，已经证明后效会在一阶和二阶线索（分别为LM和CM）之间转移。这表明在服务于它们处理的机制中存在后期联系。为了扩展对二阶线索处理机制的研究，我们考虑由局部方向调制（OM）定义的线索。使用倾斜后效（TAE）范式，我们发现LM和OM线索之间存在部分适应转移，证实了一阶和二阶线索之间存在联系。此外，我们发现OM和CM线索之间存在TAE的部分转移。这些结果表明，在适应部位或之前，来自所有视觉线索的信息被整合。然而，由于在所有情况下适应转移都低于100%，这只是信息的部分整合。
