Segmentation, attention and phenomenal visual objects

Issues concerning selective attention provoke new questions about visual se gmentation, and vice-versa. We illustrate this by describing our recent wor k on grouping under conditions of inattention, on change blindness for back ground events and the residual processing of undetected background changes. on modal versus amodal completion in visual search, and the differential e ffects of these two forms of completion on attentional processes, and on at tentional modulation of lateral interactions thought to arise in early visu al cortex. Many of these results indicate that segmentation processes subst antially constrain attentional processes. but the reverse influence is also apparent, suggesting an interactive architecture. We discuss how the 'prot o-objects' revealed by studies of segmentation and attention (i.e. the segm ented perceptual units which constrain selectivity) may relate to other obj ect-based notions in cognitive science, and we wrestle with their relation to phenomenal visual awareness. (C) 2001 Elsevier Science B.V. All rights r eserved.