An Investigation of the Relationships Between Autistic Traits and Crossmodal Correspondences in Typically Developing Adults

Autism spectrum disorder (ASD) includes characteristics such as social and behavioral deficits that are considered common across the general population rather than unique to people with the diagnosis. People with ASD are reported to have sensory irregularities, including crossmodal perception. Crossmodal correspondences are phenomena in which arbitrary crossmodal inputs affect behavioral performance. Crossmodal correspondences are considered to be established through associative learning, but the learning cues are considered to differ across the types of correspondences. In order to investigate whether and how ASD traits affect crossmodal associative learning, this study examined the relationships between the magnitude of crossmodal correspondences and the degree of ASD traits among non-diagnosed adults. We found that, among three types of crossmodal correspondences (brightness-loudness, visual size-pitch, and visual location-pitch pairs), the brightness-loudness pair was related with total ASD traits and a subtrait (social skill). The magnitude of newly learned crossmodal associations (the visual apparent motion direction-pitch pair) also showed a relationship with an ASD subtrait (attention switching). These findings demonstrate that there are unique relationships between crossmodal associations and ASD traits, indicating that each ASD trait is differently involved in sensory associative learning.