Resumen
According to the Complementary Learning Systems model of word learning, newly learned words that have been integrated into semantic memory can interact with familiar words during lexical selection. The study reported here is the first to examine behavioural and electrophysiological markers of integration in a version of the semantic priming paradigm that is assumed to rely primarily on automatic semantic processing. Seventy-one young healthy adults learned novel names for two sets of novel concepts, one set on each of two consecutive days. On Day 2, learning was followed by a primed lexical decision task (word-nonword discrimination), in which the trained novel names were targets and (semantically related and unrelated) familiar words were primes. Importantly, participants judged both primes and targets for lexicality (continuous lexical decision), and their electrical brain activity, response accuracy, and response times were recorded. In a pre-registered analysis, we examined whether there was evidence for semantic priming effects in the behavioural (response times) and electrophysiological (event-related potentials) data, and we also studied how the ERPs for the trained novel names differed from those for existing familiar words and from those for previously unseen nonwords. We found evidence for a small behavioural priming effect for novel names after a 24-hour consolidation period. In the electrophysiological data, no priming effects were observed in the pre-defined spatiotemporal windows (N400 and LPC), however, differences between the two sets of novel names were found at other locations and latencies. Additionally, in the N400 window, novel names trained immediately before testing (0-hour consolidation) differed from both familiar and untrained novel words. We suggest that, 24 hours after exposure, although the integration process is under way, it is episodic, and not semantic, memory that must be relied upon to distinguish the novel names learned 24 hours ago from those learned more recently and from those novel names that haven’t been seen before.
