Attention Orienting to Direct Gaze in Young Children with Autism Spectrum Disorder - a Heart Rate Study
Reduced use of eye contact is a prominent characteristic of individuals with autism spectrum disorder (ASD). It has been disputed whether this reflects 1) active avoidance due to negatively valenced heightened arousal to eye contact or 2) passive avoidance due to diminished attention towards eyes.
The objective was to investigate whether young children with ASD show a normative physiological index of attentional orienting to direct vs. averted gaze. To this end, we measured heart rate deceleration (orientation) responses. It was hypothesized that the direct gaze would elicit stronger orientation response than averted gaze in children without ASD, whereas this would not be observed in children with ASD.
20 children with ASD (2.5 – 5.3 years, developmental age 1.2 – 4.2 years), 20 typically developing control children matched by chronological age, and 18 children with developmental delay matched with developmental age were presented pictures of faces with direct and averted gaze directions. During the stimulus presentation, their heart rate and eye movements were recorded and evaluated. The experiment was repeated after 4-5 months with the same participants, to see whether the results of the initial experiment could be replicated.
The results of the initial experiment showed that, in the control children (both typically developing and with developmental delay), the heart rate deceleration response was more prominent to direct than to averted gaze. No heart rate deceleration was observed in children with ASD in either gaze condition. Based on eye tracker data, the lack of heart rate deceleration was not explained by reduced looking at the eye region. In the follow-up visit, the control children responded to both gaze directions with more prominent heart rate deceleration than the ASD children. Again, no heart rate deceleration was observer in children with ASD.
The results indicated that, in contrast to children without ASD, children with ASD do not show heart rate deceleration to direct or averted gaze. These findings support the assumption that direct gaze, or perhaps faces in overall, do not attract the attention of the children with ASD and this leads to reduced initiation of eye contact.