Abstract
A recent study showed that amodal completion, which is typically viewed as bottom-up process, can be influenced by high-level visual processes such as visual short-term memory (VSTM; Lee & Vecera, 2005). In the present study, we investigated whether the VSTM influence on amodal completion is caused by a general working memory load or by a memory of the to-be-completed object in VSTM. We used squared c-shaped objects that could be completed as two rectangles when an occluder was present. Experiments 1, 2 and 3 replicated the previous findings of an object-based attentional benefit based on a unitary object, on a completed object and on a completed image with preview display. In Experiment 4, participants remembered one of the c-shaped objects for a later memory-probe task. The results showed that when the remembered object was cued, there was an object-based benefit based on the object's remembered shape, not the completed shapes. However when the other, unremembered object was cued, there was an object-based benefit based on completed image. These results suggest that both VSTM and bottom-up images cues influence amodal completion on a trial-by-trial basis.
This research was supported by grant from the National Science Foundation (BCS 03-39171)