Visual Attention to Faces, Eyes and Objects : Studies of Typically and Atypically Developing Children

Abstract: Abstract. The overall aim of this doctoral work is to understand attentional functions in typically developing infants, and in children with two psychiatric conditions: autism spectrum disorder (ASD) and social anxiety disorder (SAD). Previous research has shown that attention can be subdivided into a number of interacting functions. Studies I and II examined interactions between two of these, called orienting and phasic alerting. Orienting can be defined as selection of some parts of the surroundings for further processing, and phasic alerting as a short term increase in alertness and arousal that is typically caused by external sensory input. Phasic alerting affects multiple aspects of visual orienting, but these effects are complex and dependent on multiple factors such as age and the nature of the visual environment. In study I, we examined how phasic alerting affects six month old infants’ tendency to orient their gaze to important visual stimuli such as faces and eyes. Phasic alerting was manipulated with brief sounds, and physiological arousal was measured with pupil dilation. Moderate levels of arousal, induced by non-social sounds, facilitated orienting. Study II examined how phasic alerting affects a special form of orienting called visual disengagement. We studied this question in a group of school age children with autism spectrum disorder (ASD; mean age, 6.5 years). Previous studies have suggested that ASD is associated with atypical visual disengagement, but the literature is inconclusive. Our results suggest that that phasic alerting facilitates disengagement in children with ASD as well as in typically developing children. However, ASD was associated with a general delay in visual disengagement. Study III assessed the overlap between symptoms of ASD and social anxiety disorder (SAD) in terms of visual social attention. Both conditions are associated with atypical attention to other peoples’ eyes. Participants were adolescents with a diagnosis of SAD. We measured the latency to orient to isolated eyes, and the latency to orient away from the eyes once they were fixated. The first measure was related to the level of ASD symptoms, whereas the second measure was related to SAD symptoms. This suggests a double dissociation between symptom dimensions of ASD and ASD in terms of social attention. Together, these studies contribute to our understanding of quick attention processes in typically and atypically developing populations.