What Makes the Detection of Movement Different Within the Autistic Traits Spectrum? Evidence From the Audiovisual Depth Paradigm.

Atypical sensory processing is now considered a diagnostic feature of autism. Although multisensory integration (MSI) may have cascading effects on the development of higher-level skills such as socio-communicative functioning, there is a clear lack of understanding of how autistic individuals integrate multiple sensory inputs. Multisensory dynamic information is a more ecological construct than static stimuli, reflecting naturalistic sensory experiences given that our environment involves moving stimulation of more than one sensory modality at a time. In particular, depth movement informs about crucial social (approaching to interact) and non-social (avoiding threats/collisions) information. As autistic characteristics are distributed on a spectrum over clinical and general populations, our work aimed to explore the multisensory integration of depth cues in the autistic personality spectrum, using a go/no-go detection task. The autistic profile of 38 participants from the general population was assessed using questionnaires extensively used in the literature. Participants performed a detection task of auditory and/or visual depth moving stimuli compared to static stimuli. We found that subjects with high-autistic traits overreacted to depth movement and exhibited faster reaction times to audiovisual cues, particularly when the audiovisual stimuli were looming and/or were presented at a fast speed. These results provide evidence of sensory particularities in people with high-autistic traits and suggest that low-level stages of multisensory integration could operate differently all along the autistic personality spectrum.