Contour grouping inside and outside of facial contexts.

We examine how contours group in isolation compared with when they are embedded in face-like contexts. As previously shown, contours that seem to group by phenomenological observation also show powerful effects on task performance: with contours that group, selective attention to one while ignoring another is poor (as indexed by Garner Interference (GI), but not Stroop Interference), whereas divided attention across contours is good. With contours that do not group, however, the reverse happens.