Return of fear following extinction in youth: An event-related potential study.

The ability to learn to differentiate safety from danger matures gradually, particularly when such learning occurs over an extended time period. And yet, most research on fear learning examines the early phases of such learning and mainly in adults. The current study examined fear conditioning and extinction, as well as one form of extended learning, return of fear (ROF). Thirty-three typically developing children (age range: 7-14 years) completed fear conditioning and extinction; self-reports and psychophysiological indices were measured at this point. Two weeks later, children completed a ROF test (n = 23), and event-related potentials (ERPs) were recorded. Results indicated successful fear acquisition and extinction. Moreover, participants reported greater fear of the conditioned stimulus (CS+) than the safety stimulus (CS-) in the ROF test 2 weeks later. In electrophysiology data, ROF manifested as a larger late positive potential (LPP) response to the CS+ than the CS-. Finally, these differences in LPP responses were positively correlated with poorer extinction, as indicated by the GSR responses 2 weeks earlier. This is the first ERP study to demonstrate ROF in children. The LPP measure may index an interplay between inhibitory and excitatory brain-related processes underlying the long-term effects of fear learning.