Comparison of face attention bias in adults with ASD, ADHD or double diagnosis ADHD+ASD

Faces are crucial sources of information for social interaction and cognition. This importance is reflected in increased attention, referred to as face attention bias (FAB). This preregistered study investigated FAB in adults with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), two neurodevelopmental disorders associated with social symptoms. We hypothesised decreased FAB in ASD and altered FAB in ADHD. We assessed exogenous selective attention to faces using a dot-probe paradigm. While a general FAB was observed across groups, autistic adults did not exhibit decreased FAB, contrary to expectations. Critically, adults with ADHD but no ASD showed increased FAB, suggesting heightened exogenous selective attention towards faces. This increase was not reflected in oculomotor behaviour, indicating covert attentional mechanisms. Adults with comorbid ASD and ADHD did not show increased FAB. Saccades were produced faster towards face-cued targets across all groups, but no significant interaction with group emerged regarding oculomotor behaviour. These findings challenge the notion of globally attenuated social attention in ASD, suggesting that not capturing but keeping the attention might differ from non-autistic adults. Moreover, the results highlight the effect of attention dysregulation in ADHD on exogenous selective attention towards faces, potentially contributing to social symptoms.