Error-related brain activity: A time-domain and time-frequency investigation in pediatric obsessive–compulsive disorder

Increased error- related negativity (ERN), a measure of error monitoring, has been suggested as a biomarker of obsessive– compulsive disorder (OCD). Additional insight into error monitoring is possible using time- frequency decomposition of electroencephalographic (EEG) data, as it allows disentangling the brain's parallel processing of information. Greater error- related theta is thought to re-flect an error detection signal, while delta activity may reflect more elaborative post- detection processes (i.e., strategic adjustments). Recent investigations show that decreased error- related alpha may index attentional engagement following errors; additionally, increases and decreases in error- related beta could reflect motor inhibition and motor preparation, respectively. However, time- frequency dynamics of error monitoring in OCD are largely unknown. The present study examined time- frequency theta, delta, alpha and beta power in early adolescents with OCD using a data- driven, cluster- based approach. The aim was to explore electrocortical measures of error monitoring in early adolescents with (n= 27, 15 females) and without OCD (n= 27, 14 females) during an arrowhead version of the flanker task while EEG activity was recorded. Results indicated that the OCD group was characterized by increased ERN and error- related theta, as well as reduced error- related beta power decrease (i.e., greater power) compared to participants without OCD. Greater error- related beta explained variance in OCD over and above the ERN and error- related theta. By examining separate time- frequency measures, the present study provides novel insights into the dynamics of error monitoring, suggesting that pediatric OCD may be characterized by en-hanced error monitoring (i.e., greater theta power) and post- error inhibition (i.e., reduced beta power decrease).