Intact facial adaptation in autistic adults.
Cook R., Brewer R., Shah P., Bird G.
Adaptation paradigms seek to bias subsequently viewed stimuli through prolonged exposure to an adapting stimulus, thereby giving rise to an aftereffect. Recent experiments have found that children with autism spectrum disorders (ASD) show reduced facial aftereffects, prompting some researchers to speculate that all individuals with ASD exhibit deficient facial adaptation. However, caution is required when generalizing findings from samples of children with ASD to the wider ASD population. The reduced facial aftereffects seen in child samples may instead reflect delayed or atypical developmental trajectories, whereby individuals with ASD are slower to develop adaptive mechanisms. In the present study, two experiments were conducted to determine whether high-functioning adults with ASD also show diminished aftereffects for facial identity and expression. In Experiment 1, using a procedure that minimized the contribution of low-level retinotopic adaptation, we observed substantial aftereffects comparable to those seen in matched controls, for both facial identity and expression. A similar pattern of results was seen in Experiment 2 using a revised procedure that increased the contribution of retinotopic adaptation to the facial aftereffects observed. That adults with autism can show robust facial aftereffects raises the possibility that group differences are seen only at particular points during development, and may not be a lifelong feature of the condition.