Autonomic and behavioral responses of children with autism to auditory stimulation

This study investigated the relationship between autonomic reactivity and behavioral responses to auditory stimulation in 22 high-functioning children with autism (AD) and twenty typically-developing children (TD). A primary purpose was to examine whether the AD and TD groups differed with respect to autonomic activity at rest and following auditory stimulation. An additional purpose was to investigate whether the severity of behavioral difficulties with auditory stimuli in everyday life, as reported by parents, was associated with electrodermal responses to auditory stimuli presented in a controlled laboratory setting. Electrodermal activity (EDA) was measured at rest and in response to two auditory stimuli, a tone and a siren, using the Sensory Challenge Protocol. Behavioral difficulties were measured with the Sensory Processing Measure (SPM) Home Form. T-tests were applied to EDA variables to detect differences between the two study groups. Confounding effects of gender, age, and ethnicity on EDA findings were also analyzed. Associations between EDA measures and SPM scores were determined using Pearson correlation procedures.;Results showed that the AD group had higher resting EDA levels and stronger EDA reactivity to auditory stimuli than the TD group. These findings suggest that the children with autism generally had higher arousal levels and were more physiologically reactive to auditory stimuli than the typically-developing children. Parent responses on the SPM Home Form showed that 90% of the participants with autism had behavioral difficulties with auditory stimuli in naturally occurring situations. Correlations between EDA and SPM measures indicated that more severe behavioral difficulties with auditory stimuli were associated with higher arousal levels and stronger physiological reactions to auditory stimuli. Overall, results suggested that high arousal levels may underlie some behavioral problems that children with autism experience in reaction to auditory stimuli in natural environments.