Normative Reactivity to the Emotions of Familiar People in Young Children with Autism Spectrum Disorder

Background: Individuals with Autism Spectrum Disorder (ASD) are often reported to have difficulty with emotion processing. However, clinical and experimental data show that individuals with ASD are sensitive to familiarity (e.g., they show normative attachment to familiar people), and they can share emotions with familiar others.

Objectives: Our aim in this study was to determine whether individuals with ASD would show normative physiological reactivity to the emotions of familiar people.

Methods: Participants were 25 young children with ASD and 22 young children with typical development, aged 2 to 5 years. The children observed videos of familiar people (therapists/ child-care workers) and unfamiliar people expressing emotions (happy and fear), whilst their pupillary reactions were recorded using eye tracking technology. Visual attention (fixations) was also recorded to ensure children were looking at the emotional stimuli.

Results: Preliminary data analysis indicates that children in both groups differentiate between emotions and familarity levels. The children with ASD showed a similar pattern of pupillary reactivity to the children with TD, but with one exception. The TD group, but not the ASD group, exhibited pupil dilation to unfamiliar people expressing fear. Although the children with ASD fixated less to emotions overall than the TD group, the pattern of fixations across stimuli was similar between groups.

Conclusions: As suggested by previous clinical and experimental findings, children with ASD react normatively to emotions of familiar people. Moreover, in responding to emotions, they appear to differentiate between familiar and unfamilar people as do children with TD, but demonstrate hypo-reactivity to the expression of fear by unfamiliar people. These data have important research (i.e., use of unfamiliar people in emotional stimuli) and clinical implications.