Abstract
A figure presented in the near periphery on a background of dynamic noise will become filled-in by its background, after a few seconds of central fixation. Neurophysiological, imaging and behavioural studies suggest that this process is likely to take place in early visual cortex. However, it has been recently shown (PDW, JOCN 2006) that directing spatial attention to features of the figure increases the probability of filling-in, suggesting a possible role for top-down attentional signals. To investigate these, we manipulated attentional load in a central task while participants reported the occurrence of perceptual completion for an achromatic target on a textured background in the periphery. Both time to filling-in and duration of filling-in were dramatically and significantly modulated by central attentional load. This suggests that availability of attentional resources influences the occurrence and duration of perceptual completion. We further explore how the nature of the central task influences perceptual completion, and discuss our findings in the context of Lavie's load theory of attention (Lavie TICS 2005). Taken together, our findings provide further evidence that this early visual phenomenon is subject to modulation by higher cognitive processes.