Abstract
Distorting faces by changing the distances between internal features alters perceived configuration and induces strong aftereffects in the appearance of the original face (Webster and MacLin, Psychonomic Bulletin, 1999). We compared these local distortion aftereffects for images that were also globally distorted by stretching the entire picture. This change in aspect ratio also alters feature distances yet has comparatively little effect on perceived identity (Hole et al., Perception, 2002). Faces were shown with the full head or cropped to show only the internal face or specific features, so that the source of the distortion (local vs. global) was increasingly ambiguous. After adapting to different combinations of local or global changes, a staircase was used to vary the local distortions to null any aftereffect. For most observers, aftereffects were similar for the full face images regardless of the relative aspect ratios of the images. Thus contracted faces induced expanded aftereffects whether the picture as a whole was contracted or expanded. The transfer of the aftereffects across global distortions suggests that the adaptation is adjusting at least in part to high-level image properties like perceived identity.