Abstract
The brain's ability to handle sensory information is influenced by both selective attention and awareness. There is still no consensus on the exact relationship between these two processes and whether or not they are distinct. So far, no experiment simultaneously manipulated both, which severely hampers discussions on this issue. We here describe a full factorial study of the influences of attention and awareness (as assayed by visibility) on afterimages. We investigated the duration of afterimages for all four combinations of high versus low attention and visible versus invisible grating. We demonstrate that selective attention and visual awareness have opposite effects: paying attention to the grating decreases the duration of its afterimage, while consciously seeing the grating increases afterimage duration. We moreover control for various possible confounds, including stimulus, and task changes. These data provide clear evidence for distinctive influences of selective attention and awareness on visual perception.