Heterogeneous relationships between the multisensory content of aphantasics' dreams and their volitional waking...

Aphantasia was initially characterised as a pictorial imaginative deficit, but many people with Aphantasia also report having imaginative inabilities for other sensory modalities, such as for imagined sensations of audition, taste, smell, touch, and of body movements. Moreover, patterns of imaginative inability across different types of imagined experience are individually specific to different Aphantasics. Many Aphantasics also report having visual dreams, which has prompted the suggestion that Aphantasia might be an imaginative inability specific to volitional waking imagined sensations. Until now, no study had investigated the multisensory profiles of Aphantasics' dreams, to assess how these might relate to their volitional waking imagined experiences. Here, we make that assessment and find that there is typically a correspondence between the reported multisensory contents of Aphantasics' dreams and their volitional waking imagined experiences. However, there is considerable heterogeneity, with tight associations between the reported multisensory content of some Aphantasic's dreams and their volitional waking imagined sensations, and little or no correspondence between the multisensory profiles of imagined sensations across different states of consciousness in other Aphantasics. Our data challenge researchers and theorists of Aphantasia to explain why different Aphantasics report having different contingencies between their volitional waking and dreamt imagined sensations - with one possibility being that neurological differences exist that account for these diverse outcomes.