Event-related potentials (ERPs) were used to investigate the cognitive and neural substrates of immediate and 1-week delayed error correction in a semantic retrieval task. In particular, we pursued the basis for the 'hypercorrection' effect, the finding that erroneous responses endorsed as correct with high confidence are more likely than low-confidence errors to be corrected at retest. Presentation of negative, but not positive feedback about the accuracy of one's response elicited a fronto-central negativity, similar to the ERN, which was somewhat sensitive to the degree to which negative feedback violated expectation. A fronto-central positivity, similar to the novelty-P3/P3a, more generally indexed detection of a metamemory error, given that it was larger in conditions of high metamemory mismatch than in conditions of low metamemory mismatch, irrespective of absolute task accuracy. For errors, amplitude of the fronto-central positivity, but not the preceding negativity, was correlated with correction on an immediate retest. Thus, to the extent that the fronto-central positivity indexes an orienting response, this response appears to facilitate initial encoding processes, but does not play a key role in memory consolidation. In contrast, a broad, inferior-temporal negativity occurring 300-600 ms after presentation of the correct answer was sensitive to subsequent memory performance at both immediate and delayed retests, but only for answers containing familiar semantic information. This negativity may reflect processes involved in the formation of an association between the question and pre-existing semantic information.