Associations between symptom severity in autism and functional neuroimaging measures of audiovisual speech perception.

This study looked at how well autistic people combine what they hear and see when understanding speech in noisy environments. Researchers found that autistic individuals with more severe symptoms had more difficulty using lip-reading to help understand speech. Brain scans showed these individuals had less activity in brain areas that normally combine hearing and vision. This suggests specific challenges with processing multiple senses together rather than hearing problems alone.

This neuroimaging study examined how autism symptom severity relates to audiovisual speech processing abilities in 37 participants. Using functional brain imaging and behavioral tasks, researchers found that higher autism symptom severity (measured by Calibrated Symptom Severity Scores) was associated with reduced benefit from visual lip-reading cues during speech-in-noise tasks. Brain imaging revealed that individuals with more severe symptoms showed less multisensory integration in brain regions responsible for speech and language processing. Importantly, difficulties were specific to combining audio and visual information rather than auditory processing alone, suggesting targeted multisensory processing deficits in autism.

Findings suggest speech therapy approaches should consider multisensory integration training rather than focusing solely on auditory processing. Assessment of audiovisual speech processing may help identify individuals who would benefit from targeted multisensory interventions.

Small sample size (n=37 for neuroimaging). Exploratory analysis of speech motor regions requires replication. Study design and participant characteristics not fully detailed in abstract.

Individuals on the Autism Spectrum do not benefit as much from visual articulatory cues when compared to neurotypicals, especially under noisy environmental conditions. We hypothesized that this deficit would vary with the severity of Autism related symptoms and assessed this relationship in a behavioral speech-in-noise task (n = 32) and a functional neuroimaging study (n = 37). We found that Calibrated Symptom Severity Scores (CSS) were associated with poorer audiovisual performance but not performance in the auditory-alone condition indicating that impairments are limited to multisensory (MS) information processing. These findings underscore the validity of MS deficits and their potential relevance to the broader symptomatology in Autism.

We also found that CSS significantly correlated with hemodynamic responses to audiovisual stimulation. Here, higher symptom severity was associated with lower multisensory gain in dorsal speech and language regions. Subsequent exploratory analysis suggested that individuals with Autism may not engage speech motor regions in similar ways to typically developing (TD) individuals.