The effect of visual experience on texture segmentation without awareness.

The effect of visual experience is usually investigated through active (task dependent) training in a discrimination task. In contrast, the current work explored the psychophysical and electrophysiological correlates of passive (task independent) visual experience in texture segmentation by using an inattentional blindness-like paradigm (Mack et al., 1992). The psychophysical and electrophysiological responses to a segmented line-texture bar, with texture elements oriented either congruently (parallel) or noncongruently (orthogonal) to bar orientation, were collected after both short and long passive experience, with the texture presented on the background while subjects performed a primary task. Subjects were not able to distinguish the orientation of the bar (psychophysical results) after either short or long passive experience. However, the short experience produced an electrophysiological correlate of texture segmentation (N150), and the amplitude of this component was greater for the parallel bar, demonstrating that it reflected not simply local orientation discontinuities but also texture boundary-surface orientation congruency. This configurational effect in texture segmentation, which occurred without awareness during passive viewing, disappeared when the subjects had previously discriminated the orientation of the bar and when experience was lengthened, probably as a consequence of adaptation. Our study provides the first ERP evidence that boundary-surface relations are available during short passive visual experiences of very salient texture images and are suppressed by long experience, probably because of adaptation.