Either CS1 or CS2 extinction following exposure to the US alone disrupted the reconsolidation of fear conditioning in response to both the CS1 and CS2 in humans. (A) Experimental design and timeline. (B) Mean differential SCR (CS1+ minus CS− or CS2+ minus CS−) during acquisition (late phase), extinction (last trial), spontaneous recovery test (first trial), and reinstatement (first trial). *p < .05, comparisons between acquisition and extinction, between the last trial of extinction (CS1+) and first trial of spontaneous recovery (CS1+ and CS2+), and between the last trial of spontaneous recovery and reinstatement (all within-group). The data are expressed as mean ± SEM (n = 18–19 per group).