2016 Gatlinburg Conference Poster
PS-73
Title: Physiological and Neural Mechanisms of Eating Behavior in Autism Spectrum Disorder
Authors: Lauren Little, Rebecca Lepping, Winnie Dunn, Cary Savage
Introduction: Unusual eating behavior (e.g., food selectivity, aversion to novel foods) presents in up to 90% of individuals with
autism spectrum disorder (ASD) (e.g., Mari-Bauset et al., 2013). Eating behavior in ASD overlaps with eating disordered
populations (obesity, anorexia); studies with these populations have shown that physiological and neural mechanisms associated
with disgust/reward underlie atypical eating. Therefore, we investigated the extent to which generalized food motivation
(measured via fMRI) and temporal profiles of disgust/reward (measured via facial EMG) differed between adolescents with ASD
versus typical development (TD).
Methods: Participants included adolescents with ASD (n=10) (mean age=12.8 yrs; SD=1.5 yrs) and TD (n=9) (mean age=13.3 yrs;
SD=2.1 yrs); recruitment and testing is ongoing. We used facial EMG to test affective responses to food images, and data is
collected using 4-mm electrodes placed along the zygomaticus (reward response) on the left cheek and the corrugator (disgust
response) above the left eyebrow. A standardized block design was used in our imaging paradigm to display food, non-food
(animal), and blurred baseline images (see Martin et al., 2010). Functional connectivity was measured with blood-oxygenation
level dependent (BOLD) images when participants were mild fasting (post 4-hours eating). Participants completed cognitive,
sensory, food selectivity, and autism diagnostic assessments.
Results: We obtained meaningful fMRI data from all children; movement analyses show 71% usable data in ASD and 90% in
controls. Preliminary fMRI results suggest that in response to food images, children with ASD versus TD showed differential
activations in the hippocampus based on their sensory sensitivity scores (threshold p<.05, corrected for multiple comparisons).
Children with ASD that show decreased hippocampus activation to food show high sensitivity scores; children with ASD with
lower sensitivity scores show higher hippocampal activation. Activation and sensitivity patterns in TD show an opposite trend.
Analysis of facial EMG data is ongoing; preliminary results suggest that children with ASD show increased disgust responses to
food versus controls.
Discussion: Findings suggest that children with ASD show differences in neural responses to food images as compared to
controls. The interaction between sensory sensitivity and hippocampus activation across groups may be indicative of how
memory retrieval and appraisal of emotionally salient stimuli plays a role in eating behavior and associated sensory sensitivity in
ASD. It may be that children with ASD are limited in generalizing experience with familiar foods to novel presentations of food.
Restricted eating behavior (i.e., only eating one color of food; using one plate) may be related to how children with ASD
recognize food as palatable, and memory retrieval may be related to this process in ASD.
References/Citations:
• Marí-Bauset, S., Zazpe, I., Mari-Sanchis, A., Llopis-González, A., & Morales-Suárez-Varela, M. (2014). Journal of Child
Neurology, 29(11), 1554-1561.
• Martin, L. E., Holsen, L. M., Chambers, R. J., Bruce, A. S., Brooks, W. M., Zarcone, J. R., & Savage, C. R. (2010). Neural
mechanisms associated with food motivation in obese and healthy weight adults. Obesity, 18(2), 254-260.