It has been established that successful ignoring of irrelevant distractors depends on the extent to which the current task loads attention. However, the previous load studies have typically employed neutral distractor stimuli (e.g., letters). In the experiments reported here, we examined whether the perception of irrelevant distractor faces would show the same effects. We manipulated attentional load in a relevant task of name search by varying the search set size and found that whereas congruency effects from meaningful nonface distractors were eliminated by higher search load, interference from distractor faces was entirely unaffected by search load. These results support the idea that face processing may be mandatory and generalize the load theory to the processing of meaningful and more complex nonface distractors.

Observers seem surprisingly poor at detecting changes in images following a large transient or flicker. In this study, we compared this change blindness phenomenon between human faces and other common objects (e.g., clothes). We found that changes were detected far more rapidly and accurately in faces than in other objects. This advantage for faces, however, was found only for upright faces in multiple-object arrays, and was completely eliminated when displays showed one photograph only or when the pictures were inverted. These results suggest a special role for faces in competition for visual attention, and provide support for previous claims that human faces are processed differently than stimuli that may be of less biological significance.

Issues concerning selective attention provoke new questions about visual segmentation, and vice-versa. We illustrate this by describing our recent work on grouping under conditions of inattention, on change blindness for background events and the residual processing of undetected background changes, on modal versus amodal completion in visual search, and the differential effects of these two forms of completion on attentional processes, and on attentional modulation of lateral interactions thought to arise in early visual cortex. Many of these results indicate that segmentation processes substantially constrain attentional processes, but the reverse in¯uence is also apparent, suggesting an interactive architecture. We discuss how the`proto-objects' revealed by studies of segmentation and attention (i.e. the segmented perceptual units which constrain selectivity) may relate to other object-based notions in cognitive science, and we wrestle with their relation to phenomenal visual awareness. q

People often are unable to report the content of ignored information, but it is unknown whether this reflects a complete failure to perceive it (inattentional blindness) or merely that it is rapidly forgotten (inattentional amnesia). Here functional imaging is used to address this issue by measuring brain activity for unattended words. When attention is fully engaged with other material, the brain no longer differentiates between meaningful words and random letters, even when they are looked at directly. These results demonstrate true inattentional blindness for words and show that visual recognition wholly depends on attention even for highly familiar and meaningful stimuli at the center of gaze.