Mental imagery: pulling the plug on perceptualism

Dan Cavedon-Taylor

doi:10.1007/s11098-021-01628-x

Abstract

What is the relationship between perception and mental imagery? I aim to eliminate an answer that I call perceptualism about mental imagery. Strong perceptualism, defended by Bence Nanay, predictive processing theorists, and several others, claims that imagery is a kind of perceptual state. Weak perceptualism, defended by M. G. F. Martin and Matthew Soteriou, claims that mental imagery is a representation of a perceptual state, a view sometimes called The Dependency Thesis. Strong perceptualism is to be rejected since it misclassifies imagery disorders and abnormalities as perceptual disorders and abnormalities. Weak Perceptualism is to be rejected since it gets wrong the aim and accuracy conditions of a whole class of mental imagery–projected mental imagery–and relies on an impoverished concept of perceptual states, ignoring certain of their structural features. Whatever the relationship between perception and imagery, the perceptualist has it wrong.

Highlights

Visualise a red door for a few seconds
Both agree that perceptual experience is the key to unlocking the mysteries of mental imagery. For all their disagreement, agree crucially on this: mental imagery cannot be understood apart from perception. Where they differ is merely over the sort of conceptual connection imagery is said to bear to perception: whether ‘imagery’ names a type of psychological state that is a proper subset of perceptual experience or else names a type of state that necessarily represents perceptual experience
If strong perceptualism as a thesis about mental states is the claim that mental imagery is a subset of perceptual experience, what is strong perceptualism as a thesis about perceptual processing? Here are two representative statements: Mental imagery, according to this paradigm, is perceptual processing that is not triggered by corresponding sensory stimulation in a given sense modality. (2018, p.127) I will use the concept of mental imagery as a technical concept in this paper and use the term ‘mental imagery’ as a shorthand for ‘perceptual processing that is not triggered by corresponding sensory stimulation in the relevant sense modality’. (2020, p.83)

Summary

Introduction

Visualise a red door for a few seconds. What kind of psychological state were you just in? Silly question. How might one argue that mental images are perceptual states? Mental imagery shares with perception nonconceptual content, representing objects and properties in a concept-free way. Considered in isolation, any one of these might form the basis of an argument for mental imagery’s being a perceptual state; considered cumulatively, the case seems positively overdetermined. I won’t be making a positive case for any non-perceptual theory of mental imagery; my project is wholly negative, to eliminate one (really, two) answer(s) to the question ‘how are perception and imagery related?’ it might be. How might one begin to support any of these alternatives in light of the overwhelming number of resemblances between imagery and perception just listed?

Two kinds of perceptualism

Against strong perceptualism