Change detection of task-relevant and task-irrelevant emotional faces: behavioural and ERP evidence

Adaptive social interaction requires rapid detection of changes in facial expressions. Socio-emotional difficulties may alter this processing, but evidence from preclinical populations and the role of comorbid symptoms remain limited. Event-related potentials (ERPs), particularly amplitude modulations in N170, and P3 during change detection tasks, have been associated with predictive coding. However, their interpretation has been limited by the absence of adequate control tasks. We investigated ERPs (P1, N170, P3b) and behavioural responses to facial expression changes, as well as the effects of stress, depression, and anxiety. Sad and angry deviant faces were interspersed among neutral standard faces in both the task-relevant and task-irrelevant oddball contexts. Amplitude modulation (emotional-neutral) in the N170 and P3b was larger for task-relevant angry than sad faces. Based on the control task available for the task-irrelevant context, the ERP modulations could not be attributed to predictive coding. Findings of individual differences emerged only behaviourally: higher stress was linked to slower reactions to angry faces. Overall, the results indicate rapid processing of emotional faces, without evidence of predictive coding or robust effects of depressive or anxiety symptoms.