The P600 during Sentence Reading Predicts Behavioral and Neural Markers of Recognition Memory.

The P600 ERP component is elicited by a wide range of anomalies and ambiguities during sentence comprehension and remains important for neurocognitive models of language processing. It has been proposed that the P600 is a more domain-general component, signaling phasic norepinephrine release from the locus coeruleus in response to salient stimuli that require attention and behavioral adaptation. Because such norepinephrine release promotes explicit memory formation, we here investigated whether the P600 during sentence reading (encoding) is thus predictive of such explicit memory formation using a subsequent old/new word recognition task. Indeed, the P600 amplitude during our encoding task was related to behavioral recognition effects in the memory task on a trial-by-trial basis, although only for one type of violation. Recognition performance was better for semantically, but not syntactically, violated words that had previously elicited a larger P600. However, the P600 to both types of violations during encoding was positively related to a more subtle, neural marker of recognition, namely, the amplitude of the recollection ERP component in response to old words. In summary, we find that the P600 predicts later recognition memory both on the behavioral and neural level. Such explicit memory effects further link the late positivity to norepinephrine activity, suggesting a more domain-general nature of the component. The connection between the P600 and later recognition indicates that the neurocognitive processes that deal with salient and anomalous aspects in the linguistic input in the moment will also be involved in keeping this event available for later recognition.