Reconsidering the Role of Imagery in Perception

How much of what we see is imagined? Perception is a constructive process, supplementing the information available in sensory inputs to build representations of the world, as when one perceives a cat behind a chain-link fence as a whole, intact object, though it produces only a fragmented image on the eye. A recent movement in cognitive science and the philosophy of mind argues that mental imagery supplies much of the material for constructing perceptual representations—filling in the missing parts of the cat, for instance. On this “Constitutive View” of imagery’s role in perception, perceptual representations routinely contain elements of mental imagery. This view rests on an expansive conception of what mental imagery is: roughly, imagery consists in perceptual processing that is not directly connected to sensory inputs. We challenge the Constitutive View. First, we argue that the expansive conception of imagery on which the view relies is problematic, for it fails to capture a unified psychological kind. We then consider whether phenomena such as perceptual completion, in which the occluded parts of the cat are “filled in,” support the Constitutive View. We argue that there is little explanatory utility in construing perceptual completion as a form of imagery. The constructive character of perception, we suggest, is best understood on its own terms, rather than by reference to imagery.