Event-related potentials in response to irony in depressed and healthy controls

Abstract

Humor has a positive impact on psychological and physiological well-being, and it improves social interaction and relationships. Depression is associated with numerous impairments, including affective symptoms and cognitive dysfunctions. Irony is a form of spontaneous conversational humor that has not been widely studied in depression, especially on a neural level. This is despite the potential irony has to smooth social interaction and enhance coping. In the present study participants with depressive symptoms (depressed group, n = 20) and a control group (n = 22) were compared in their behavioral responses and brains’ event-related potentials (ERPs) to neutral (congruent) and ironic (incongruent) sentence-picture -pairs. Depression was associated with an increased preference for self-defeating humor and a reduced preference for self-enhancing humor. Moreover, Beck Depression Index (BDI) was negatively correlated with self-enhancing humor style. In addition, control group rated the ironic stimuli to be funnier than the depressed group. However, the depressed and the control group rated the ironic stimuli as incongruent equally well, indicating no difficulty in detecting irony. P600 and sustained left anterior negativity (sustained LAN) were larger in amplitude for the ironic than the neutral conditions, indicating an increased working memory load for irony. On the contrary, emotion-related late positive potential (LPP) showed no difference between the conditions. Unexpectedly, there were no differences between the groups in any of the ERPs. Our findings provide support to the notion that interpreting the meaning of irony involves distinct neural processing that is reflected by alterations in several ERP components. Our findings further suggest that cognitive processing of irony is preserved in depression but the affective aspect might be influenced.