Behavioral and Brain Sciences

Short Communication

The nature of mental imagery: How null is the “null hypothesis”?

Gianfranco Dalla Barba a1, Victor Rosenthal a1 and Yves-Marie Visetti a2
a1 INSERM Unit 324, Centre Paul Broca, 75014 Paris, France
a2 LATTICE-CNRS-ENS, 92120 Montrouge, France


Is mental imagery pictorial? In Pylyshyn's view no empirical data provides convincing support to the “pictorial” hypothesis of mental imagery. Phenomenology, Pylyshyn says, is deeply deceiving and offers no explanation of why and how mental imagery occurs. We suggest that Pylyshyn mistakes phenomenology for what it never pretended to be. Phenomenological evidence, if properly considered, shows that mental imagery may indeed be pictorial, though not in the way that mimics visual perception. Moreover, Pylyshyn claims that the “pictorial hypothesis” is flawed because the interpretation of “picture-like” objects in mental imagery takes a homunculus. However, the same point can be objected to Pylyshyn's own conclusion: if imagistic reasoning involves the same mechanisms and the same forms of representation as those that are involved in general reasoning, if they operate on symbol-based representations of the kind recommended by Pylyshyn (1984) and Fodor (1975), don't we need a phenomenological homunculus to tell an imagined bear from the real one?