Emotion Facial Processing in Children With Autism Spectrum Disorder: A Pilot Study of the Impact of Service Dogs

Abstract

Processing and recognizing facial expressions are key factors in human social interaction. Past research suggests that individuals with autism spectrum disorder (ASD) present difficulties to decode facial expressions. Those difficulties are notably attributed to altered strategies in the visual scanning of expressive faces. Numerous studies have demonstrated the multiple benefits of exposure to pet dogs and service dogs on the interaction skills and psychosocial development of children with ASD. However, no study has investigated if those benefits also extend to the processing of facial expressions. The aim of this study was to investigate if having a service dog had an influence on facial expression processing skills of children with ASD. Two groups of 15 children with ASD, with and without a service dog, were compared using a facial expression recognition computer task while their ocular movements were measured using an eye-tracker. While the two groups did not differ in their accuracy and reaction time, results highlighted that children with ASD owning a service dog directed less attention toward areas that were not relevant to facial expression processing. They also displayed a more differentiated scanning of relevant facial features according to the displayed emotion (i.e., they spent more time on the mouth for joy than for anger, and vice versa for the eyes area). Results from the present study suggest that having a service dog and interacting with it on a daily basis may promote the development of specific visual exploration strategies for the processing of human faces.

Keywords: autism spectrum disorder (ASD); emotion recognition; eye-tracking; facial expression processing; service dog.

FIGURE 1

Illustration of the areas of interest (AOI) applied on the avatars’ faces for the extraction of oculometry data. Left eye area in yellow, right eye area in blue, nose area in pink, mouth area in green, face contours area in white, and outside area in gray.

FIGURE 2

Mean proportion of fixation of children with ASD according to children’s group and to the displayed facial expression for: (A) the outside area, (B) the left eye area, (C) the right eye area, and (D) the mouth area. Facial expressions are represented in color code: anger in white, joy in black, neutral in dotted pattern, fear in striped pattern, and sadness in gray. Lower case-letters and stars refer significant differences. Lower-case letters refer significant results from comparisons between expressions within in each group. Data (i.e., facial expressions) referring different letters within the graph differed significantly at p ≤ 0.05, while data that share a common letter did not. Stars refer to results from comparisons between groups within each facial expression. *p ≤ 0.05, ^**p ≤ 0.01, ^***p ≤ 0.001.