Opposite effects of perceptual and working memory load on perceptual filling-in of an artificial scotoma

A target presented on a background of dynamic noise disappears from awareness after a few seconds of maintained peripheral viewing. Whereas the effects of bottom-up factors in such filling-in are well documented, the roles of different top-down functions remain relatively unexplored. Here, we investigated the roles of attention and working memory (WM) by manipulating load in concurrent tasks while participants reported filling-in of a peripheral target. In Experiment 1, increasing perceptual load reduced the probability of filling-in and increased the latency of its occurrence. In Experiment 2, increasing WM load shortened the time before filling-in occurred--the opposite effect to increasing perceptual load. These results demonstrate that different top-down functions may have dissociable effects on filling-in.