Integrating parent report, observed behavior, and physiological measures to identify biomarkers of sensory over-responsivity in autism.

backgroundSensory over-responsivity (SOR) is a heightened reaction to environmental stimuli commonly seen in autism spectrum disorder (ASD) which impacts daily functioning. Parent-reported and observed behavioral assessments are used to study SOR, but show limited associations with each other, possibly because they measure different aspects of SOR or because children inhibit their responses during standardized assessments. Physiological measures provide an objective measure of sensory reactivity, and atypical heart rate (HR) responses to aversive stimuli have been shown to be related to SOR in ASD youth. This study aimed to compare how reported and observed measures of SOR predict HR and to examine if the level of reported behavioral inhibition in ASD youth affects how observed SOR behaviors correlate with physiological reactivity.

methodsParticipants were 54 typically developing (TD) and 83 ASD youth, ages 8-17, who completed a standardized behavioral assessment of SOR while electrocardiogram recordings were collected. Participants' parents also reported on their child's SOR symptoms and behavioral inhibition.

resultsASD youth showed lower inter-beat-intervals (IBI; higher HR) across all auditory and tactile stimuli. For ASD youth, parent-reported SOR interacted with observed SOR to predict HR changes across the stimulation periods, indicating that ASD participants whose parents reported they had high SOR in their daily life, and showed high observed SOR in the lab assessment, exhibited reduced HR deceleration (orienting) after the onset of the stimulus and subsequent increased HR acceleration. Finally, we found that ASD participants who had lower parent-reported behavioral inhibition had a stronger correlation between observed SOR behavior and atypical HR responses.

conclusionsResults support prior findings that increased HR responses to aversive stimuli is related to both ASD and SOR. Furthermore, observed and parent-reported SOR interacted to predict HR, suggesting that a multi-method approach may best capture the extent of SOR for an individual. However, observed SOR measures may be most accurate for ASD youth who are less likely to inhibit their behavioral responses. This study illustrates the importance of integrating multiple measures of sensory reactivity to identify SOR. HR measures of sensory reactivity have the potential to serve as a biomarker of SOR across a diverse range of individuals.