Aphantasia and the unconscious imagery hypothesis

Abstract

Until recently, mental imagery has largely been regarded as an exclusively conscious phenomenon. However, recent empirical results suggest that mental imagery can also occur unconsciously. People who report having no experiences of mental imagery often perform similar to controls on behavioural tasks thought to require imagery. A surprising number of them also display significant levels of imagery-based priming, and recent neural decoding studies have shown that imagery-related information is being processed in their visual cortex. However, investigating unconscious imagery empirically is not straightforward. One challenge is to establish that imagery is genuinely unconscious as opposed to merely going unreported due to response biases. Another is to clarify how imagistic and indirect perceptual processing needs to be to qualify as imagery. In this paper, we take a closer look at the evidence for unconscious imagery, argue that it is not as compelling as it initially appears, and outline a strategy for advancing research on this question.