Attention-based visual routines: sprites

A central role of visual attention is to generate object descriptions that are not available from early vision. Simple examples are counting elements in a display or deciding whether a dot is inside or outside a closed contour (Ullman, Cognition 18 (1984) 97). We are interested in the high-level descriptions of dynamic patterns - the motions that characterize familiar objects undergoing stereotypical action - such as a pencil bouncing on a table top, a butterfly in Right, or a closing door. We examine whether the perception of these action patterns is mediated by attention as a high-level animation or 'sprite'. We have studied the discrimination of displays made up of simple, rigidly linked sets of points in motion: either pairs of points in orbiting motion or 11 points in biological motion mimicking human walking. We find that discrimination of even the simplest dynamic patterns demands attention. (C) 2001 Elsevier Science B.V. All rights reserved.