Recommendations for Increasing Sample Diversity in Autism Research: Lessons from Multisensory Studies.

In 2024, the United States House of Representatives passed ruling H.R.7213, the Autism CARES Act, which, if passed by the Senate, will reauthorize funding to extant national autism research programs, with an emphasis on including autistic individuals significantly affected by the disorder. This shift toward research inclusion across the autism spectrum clearly highlights the lack of representation in the past. In the field of multisensory integration, it is well documented that there are changes to how autistic individuals integrate stimuli across different sensory modalities, and the relationship between atypical (multi)sensory processing and the core features of autism is well documented. However, much of this research utilizes samples of autistic individuals with high cognitive, verbal, and functional ability. The purpose of this review is to draw attention to disparities in the samples used in multisensory research in autism. We conducted a systematic review of all studies examining multisensory function in autism to date and provide basic descriptive statistics of the studies. We observed that the vast majority of multisensory research is focused on young, low support needs autistic individuals, with very little investigation in autistic individuals with high support needs (HSN). Additionally, we found investigation into the effect of sex or comorbidities to be lacking. We propose methodological improvements addressing gaps in the research in order to make multisensory research in autism more inclusive to HSN autistics.