Exploring the association between mental imagery, sensory sensitivity, and autistic traits in autistic and non-autistic adults.

Mental imagery vividness varies between individuals. Low levels of mental imagery have been associated with high levels of autistic traits, whilst autistic traits are known to positively correlate with sensory sensitivities. This would predict a negative correlation between sensory sensitivity and imagery. However, one recent study has suggested that mental imagery vividness may be positively associated with sensory sensitivities, possibly through the shared mechanism of hyperexcitability of the sensory cortices. The aim of this paper was to explore this contradictory set of associations across two modalities (visual and tactile). We used standardised questionnaires to measure autistic traits, sensory sensitivities, and mental imagery vividness in a sample evenly comprised of autistic and non-autistic adults (n = 595). Higher autistic traits were significantly associated with lower mental imagery (r =  - 0.20 and r =  - 0.17 for visual and tactile imagery respectively), and a higher incidence of aphantasia was observed in the autistic group compared to the non-autistic group. In addition, higher autistic traits were significantly associated with increased sensory sensitivities (r = 0.76). Importantly, we found negligible evidence of an association between mental imagery and sensory sensitivity, even when controlling for autistic traits. In the first study to directly explore autistic traits, sensory sensitivities and mental imagery, we conclude that there is no clear evidence to suggest that mental imagery and sensory sensitivity are related, challenging the idea of shared mechanisms of hyperexcitability of sensory cortex.