Contributions of Parieto-Temporal Brain Activity, Medial-Frontal Brain Activity, and Vagal Control of the Heart to Social Skills in Children with Autism

Background: Research investigating the neurological causes of autism indicates that social impairments in the disorder are a result of a disturbance in a ventromedial “social brain” circuit, including the parietal-temporal lobe, and in the frontal lobe. Issues processing social stimuli neurologically present behaviorally in a difficulty initiating social behaviors. The Polyvagal theory may also help explain social deficits in autism. It suggests that humans activate different neural circuits, depending on the environment, that are manifest by different heart-rate responses. If the environment is perceived as safe, the vagus nerve slows heart rate, allowing social behaviors. However, children with autism may not adequately assess risk associated with social situations, including interacting with unfamiliar people. Objectives: This poster intends to explore the neurological concomitants of social behavior in autism, as well as the role heart rate plays in children with autism's interactions with unfamiliar people. Methods: Eighteen children with high-functioning autism, ages 8-12 (mean age 10.06; 17 males), viewed a 5-minute video of an unfamiliar person reading a story. Thirteen children without autism (mean age 9.92; 10 males) were tested as a comparison group. Brain activity in the frontal and parietal-temporal lobes was measured utilizing an EEG. A 64-channel electrode cap collected data, which was analyzed using the Scan 4.3 program. Heart rate was artifact-corrected and analyzed offline. Respiratory Sinus Arrhythmia (RSA: an index of vagal control of the heart) was calculated as the variability of heart rate associated with the .12-1.0 Hz frequency band. The Social Skills Rating System (SSRS) was completed by children's caregivers to measure social skills. The data was entered into a standard, step-wise multiple regression. Results: Results indicate that the overall model was significant, F(4, 26) = 11.07, p< .001; Adjusted R squared = .573. Also, it was found that higher levels of parietal-temporal lobe activity indicated more behaviors related to autism, β = .43, t = 2.10, p< .05, while less activity in the frontal lobe suggested more behaviors associated with autism, β= -.51, t= -2.42, p< .05. More control of heart-rate (via higher RSA) indicated less behaviors related to autism, β = 0.30, t = 2.24, p< .05. Conclusions: The findings offer implications for the differences in how children with autism utilize different areas of their brains when interacting with unfamiliar people. Higher ratings of social skills were associated with a decrease in parietal-temporal lobe activity, an increase in frontal lobe activity, and an increase in vagal control of heart rate. The parietal-temporal lobe finding may be contrary to previous research, as this area is theorized to support social behavior. However, it was also found that more activity in the frontal lobe—generally linked to executive functioning and initiating— was associated with better social skills. Lastly, it may be that children with autism exhibit less control over their heart-rate when interacting with unfamiliar people, perhaps reflecting a stress response, which affects their social behavior.