27204
Heart Activity during Startle Paradym in Children with Fragile X Syndrome and Autism Spectrum Disorder Compared to Typically Developing Children
Objectives: The purpose of this study is to characterize heart activity in response to an auditory startle in children with FXS and in children with ASD contrasted to low-risk controls. We predict that children with FXS or ASD will react with elevated heart activity to the auditory startle task compared to TD children.
Methods: Participants included 25 children with FXS, 21 TD children, and 11 children with idiopathic ASD (n =20 by INSAR) between the ages of 3-6 years old who are participating in an ongoing study. The auditory startle task takes place in the context of a silent children’s movie and is comprised of a three phases, 1). The pre-startle (30 seconds), 2) startle (1 second), and 3) post-startle (60 seconds).
Results: We examined patterns in heart activity during auditory startle response across FXS, ASD, and TD groups using a multi-level model, wherein 1s epochs were nested within children. The FXS and TD groups differed in startle response heart activity B=.50(.19), t=2.51, however, FXS and ASD groups did not B=.27(.19),t=1.39. Model results indicate that the FXS and ASD groups showed increased startle response heart rate, whereas the TD group showed a decrease (see figures).
Conclusions: These preliminary findings are consistent with previous research showing altered physiological reactivity in clinical samples with FXS and ASD compared to TD children. Results suggest that autonomic reactivity, indexed by heart rate, may represent a shared mechanistic vulnerability with anxiety in FXS and ASD. Elevated heart rate following startle response might be an early feature of anxiety in young children with FXS or ASD. Behavioral data are being coded during the startle experiment, and these data will be integrated with heart activity for presentation at the conference.