Sensorimotor-based theories of cognition predict that even subtle developmental motor differences, such as those found in individuals on the autism spectrum, affect how we represent the meaning of manipulable objects (e.g., faucet). Here, we test 85 participants, who completed the Adult Autism Spectrum Quotient (to measure autism-spectrum characteristics), on a visual world experiment designed to assess conceptual representations of manipulable objects. Participants heard words referring to manually manipulable objects (e.g., faucet) while we recorded their eye movements to arrays of four objects: the named object, a related object typically manipulated similarly (e.g., jar), and two unrelated objects. Consistent with prior work, we observed more looks to the related object than to the unrelated ones (i.e., a manipulation-relatedness effect). This effect has been taken to reflect overlapping conceptual representations of objects sharing manipulation characteristics (e.g., faucet and jar) due to embodied sensorimotor properties being part of their representations. Critically, we observed that as participant-level autism-spectrum characteristics increased, manipulation-relatedness effects became smaller, whereas in control trials that included a shape (instead of manipulation) related object, relatedness effects increased. The results support the hypothesis that differences in object-concept representations on the autism spectrum emerge at least in part via differences in sensorimotor experience.
Adult Autism Subthreshold Spectrum (AdAS Spectrum): Validation of a questionnaire investigating subthreshold autism spectrum