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Abstract

Behavioural studies have highlighted the importance of dynamic information for object recognition: Object motion provides additional views and image features that may facilitate the extraction of 3-D shape. However, even the direction of in-depth rotation that controls for shape and view information affects recognition performance. Here, we used a priming paradigm to investigate the effects of motion direction and form as well as their interaction during dynamic object recognition. Furthermore, two task-contexts were used to investigate the effects of top - down modulation on behavioural priming effects. For these contexts, subjects responded on the basis of object form or motion. Subjects were presented with pairs of successive objects rotating in depth. They performed a two-alternative forced choice form or motion categorisation to the second object. The conditions conformed to a 2 × 2 × 2 factorial design manipulating (i) object form (same/different pairs), (ii) in-depth rotation (same/different pairs), and (iii) task (motion/form). We observed that form and motion priming effects interacted and were enhanced in congruent task context. These findings suggest that dynamic 3-D object recognition is accomplished through interaction of form and motion information. Furthermore, both form and motion priming are influenced by task requirements. Future fMRI studies will investigate these effects at the neuronal level.