Cognitive Control of Emotional Information in Major Depression: An ERP Study Using a Face-Word Stroop Task

This event-related potential (ERP) study investigated proactive and reactive cognitive control of emotional information in major depressive disorder (MDD). Proactive control refers to biasing of information processing toward a given goal during anticipation of a relevant event; reactive control involves correction processes activated after the event to ensure goal attainment. ERPs were obtained in 39 patients with recurrent MDD and 39 controls during an emotional face-word Stroop task. Images of happy or anxious faces were presented, with the word HAPPY or ANXIOUS written across the faces, congruent or incongruent with facial expressions. Participants had to identify expressions while ignoring word meaning. The proportion of incongruent trials was manipulated (75% vs. 25%) to generate a mostly incongruent (MI) context (proactive control) and a mostly congruent (MC) context (reactive control). The N2 was taken as an index of conflict processing. In the MC context, patients showed higher error rate than controls for incongruent, but not congruent, trials. In the MI context, patients´ error rate was unaffected by congruency. No group differences arose for reaction time. The N2 amplitude was lower in patients than controls, independent of congruence and context. The pattern of error rates in both contexts suggests a cognitive control deficit in MDD that emerged in the reactive, but not the proactive, mode. The N2 reduction in patients reflects generally diminished attentional engagement in the task rather than a specific cognitive control deficit. Impaired reactive control may contribute to maladaptive automatized thinking and emotional dysregulations characterizing MDD.