Attention and neural response to gaze and emotion cues in the development of autism and autism spectrum disorders.

摘要

Understanding the nature and sources of variability in the development of autism spectrum disorders (ASD) is vital for identifying possible courses of treatment and interventions. One study used functional magnetic response imaging (fMRI) to examine neural response to cues known to be processed differently in autism, eye gaze and facial emotion, in children with autism and typically-developing (TD) controls, and another examined visual responses to the same cues in infants at greater risk of developing autism (I-Sibs). The overall aim was to identify abnormal brain-level responses measured in later childhood, and determine whether and how they may be present or have early correlates early in infancy, prior to clinical diagnosis. The first study found while that TD children showed robust recruitment of the ventrolateral prefrontal cortex (VLPFC) to angry and fearful faces with direct as opposed to averted gaze, ASD children failed to differentiate between direct and averted gaze in VLPFC, despite equal amounts of face fixation across groups. Furthermore, amount of activity across groups was positively associated with parent-reported social abilities. This region is believed to be involved in the regulation and integration of affective cues, suggesting that children with ASD fail to spontaneously process the significance of the feelings or intentions of others, signaled both by others' emotional expressions and gaze directions.;A second study presented a similar paradigm, eye-tracking a group of greater-risk infants, I-Sibs. Overall attention to faces at 6 months was disproportionately focused on eye regions, which was more pronounced for happy faces. At 12 months, I-Sibs preferred happy-direct over happy-averted gaze. Fixation of higher-functioning 12-month-olds was modulated by gaze direction and emotion. Lower-performing infants preferred angry-direct faces, whereas higher-performing infants preferred angry-averted and happy-direct faces. Findings suggest that by 12 months, higher-functioning I-Sibs adjust their visual attention according to what may be subjectively more or less pleasant or aversive.;Findings suggest that differences in appropriately interpreting gaze and emotion cues together may explain some variability in social functioning later in childhood, and may offer easily-identified early markers for infants who will subsequently develop ASD.