Neurobehavioral Assessment of Sensorimotor Function in Autism Using Smartphone Technology

Differences in sensorimotor processing represent an important, yet underrecognized, feature of autism; typically assessed through subjective observations, which, although important, are susceptible to biases. To complement these observations, a more objective approach to assess sensorimotor function may be possible through reflex-based neurobehavioral evaluations. The clinical application of these assessments has, however, been largely confined to laboratory settings. Thus, small sample sizes and inconsistent findings have made it challenging to understand how sensorimotor function differs in autism and whether it can be used as an objective biomarker for diagnostics. Here we present a novel smartphone-based platform to conduct neurobehavioral evaluations by measuring facial and behavioral responses in at-home environments. Through a multi-center study, we explored the platform's ability to distinguish between children with and without autism. We enrolled 536 children aged 3-12 years. BlinkLab smartphone-based assessments were successfully completed in 431 children (80.4%), including 275 with autism and 156 neurotypical children. We found that autistic children showed altered sensorimotor responses across multiple domains. These included reduced prepulse inhibition (PPI), stronger startle habituation over the course of a PPI test, more variable eyeblink responses to auditory stimuli and significant sensitization. Additionally, children with autism displayed more screen avoidance, postural instability, head movements, mouth openings, non-syllabic vocalizations, horizontal pupil shifts, "side-eyeing", and variation in baseline eyelid opening. Exploratory analyses showed that these effects were largely independent of co-occurring conditions. Notably, co-occurrence did influence certain subdomains (e.g., PPI, mouth openings). These findings illustrate that smartphone-based assessments can capture distinct sensorimotor profiles associated with autism in real-world environments.