Gheorghiu Elena, Kingdom Frederick A A, Witney Emma
Laboratory of Experimental Psychology, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium.
Vision Res. 2010 Oct 12;50(21):2127-36. doi: 10.1016/j.visres.2010.08.006. Epub 2010 Aug 8.
The shape-frequency and shape-amplitude after-effects, or SFAE and SAAE, are shifts in the perceived shape-frequency and perceived shape-amplitude of a sinusoidal test contour following adaptation to a similar-shaped contour. These shape-effects are the shape analogs of the well-known size after-effect discovered by Blakemore and Sutton (1969), so it is possible that they are mediated by a size-sensitive mechanism. We tested this possibility by comparing the magnitudes of SFAEs/SAAEs elicited by contour/edge adaptors with those from luminance grating and line-grating adaptors. The rationale was that if the shape after-effects using the two classes of adaptors were similar, then they would likely be mediated by the same mechanism. We found that the SFAE and SAAE were greatly reduced when using luminance and line grating adaptors, suggesting that the SFAE and SAAE are not mediated primarily by either first- or second-order size-sensitive mechanisms. Based on previous studies we conclude that SFAEs/SAAEs are mediated by mechanisms primarily sensitive to curvature.
形状频率和形状幅度后效，即SFAE和SAAE，是指在适应了形状相似的轮廓后，正弦测试轮廓的感知形状频率和感知形状幅度发生的偏移。这些形状效应是由布莱克莫尔和萨顿（1969年）发现的著名大小后效的形状类似物，所以它们有可能是由大小敏感机制介导的。我们通过比较轮廓/边缘适配器与亮度光栅和线光栅适配器所引发SFAEs/SAAEs的大小来测试这种可能性。其基本原理是，如果使用这两类适配器产生的形状后效相似，那么它们可能由相同的机制介导。我们发现，使用亮度和线光栅适配器时，SFAE和SAAE会大幅降低，这表明SFAE和SAAE并非主要由一阶或二阶大小敏感机制介导。基于之前的研究，我们得出结论，SFAEs/SAAEs是由主要对曲率敏感的机制介导的。
