Abstract
Navon (1977) demonstrated a global precedence effect in shape processing (faster judgments of local shape when local and global shapes are congruent, but not vice versa), suggesting the importance of global spatial cues (i.e. shape) in scene and object processing. Investigations of scene processing using fMRI are consistent with this, as they have demonstrated that the parahippocampal place area (PPA) represents scenes by processing global spatial properties (Epstein et al., 2003). Recent fMRI experiments show that PPA also represents scenes by processing non-spatial cues such as texture (Cant & Goodale, 2011). If texture is important in global scene perception, then in addition to the well-documented global precedence for shape, we should also observe a global precedence effect in texture processing (faster judgments of local texture when local and global textures are congruent). We investigated this in two experiments using modified Navon stimuli and cued participants to make speeded judgments of shape (star vs. heart) and texture (paint vs. rock) at both global and local levels. In Experiment 1, we integrated local and global shape and texture within a single Navon stimulus (all features were contained within a global outline contour), and observed a global precedence effect for both shape and texture. Surprisingly, we also observed a local precedence effect for texture (faster judgments of global texture when local and global textures were congruent). In Experiment 2, local and global shape remained integrated, but we separated local and global texture into foreground and background elements, respectively. We replicated global precedence effects for shape and texture, but the local precedence effect for texture was eliminated. These results demonstrate a global-processing bias for both shape and texture, and suggest that the ways in which visual features are integrated may play an important role in processing foreground (object) and background elements in scenes.
Meeting abstract presented at VSS 2014