| dc.description.abstract | Behavioral and Neural Indices of Auditory Temporal Processing
in Children with Autism Spectrum Disorders
JENNIFER H. FOSS-FEIG
Dissertation under the direction of Professors Wendy L. Stone and Bruce Compas
Sensory processing abnormalities are amongst the most commonly reported symptoms associated with autism spectrum disorders (ASD), yet there is remarkably little empirical research quantifying their nature, extent, and neurobiological origins. This study characterizes basic auditory sensory functioning using psychophysical and electrophysiological methods. Our particular focus is on temporal aspects of auditory processing, as these may underlie speech perception, and language/communication deficits are hallmarks of ASD. We examined children’s ability to resolve brief temporal events within auditory stimuli, as well as the degree to which their brains effectively process rapid changes in auditory input. Behavioral and neural responsiveness to brief silent gaps in noise were examined in 10-13 year old children with ASD, relative to age- and IQ-matched typically developing (TD) peers. Results of the psychophysical study revealed increased auditory gap detection thresholds in ASD, suggesting impaired ability to resolve rapid temporal changes in auditory stimuli. Among children with ASD, greater difficulty with auditory gap detection was associated with more substantial language-related impairments, as quantified with standardized clinical assessments. Results of the electrophysiological study, which examined event-related potentials (ERPs) during auditory gap detection, uncovered atypicalities in the neural response to rapid temporal changes in auditory events among children with ASD. Children with ASD were faster to alert to auditory stimulus onset, but showed diminished magnitudes of their early sensory responses to stimulus onset. In response to near-threshold gaps in auditory stimuli, relative to children with TD, children with ASD showed prolonged ERP responses associated with orienting of attention, and decreased amplitude of ERP responses associated with stimulus classification, particularly when gaps were not detected behaviorally. Overall findings reveal impairments in: (1) the ability of children with ASD to process brief temporal events within auditory stimuli; and (2) the timing and coordination of their neural response during auditory temporal processing. Clinically, these deficits relate to language impairments in ASD. Future research examining rapid auditory temporal processing may elucidate aberrant low-level sensory and cognitive processes in ASD, potentially informing novel interventions targeting core deficits in processing and responding to sensory input. | |
