Intra- and inter-item associations doubly dissociate the electrophysiological correlates of familiarity and recollection.

Single-process models of recognition memory posit that recognizing is based on a unidimensional value of global memory strength. By contrast, dual-process models propose the existence of two independent processes subserving the explicit recognition of previously encountered episodes, namely "familiarity" and "recollection." Familiarity represents a noncontextual form of recognition that may only support the retrieval of associative information when the to-be-associated information can be unitized, such as when two photographs depicting the same person are memorized (intra-item associations). Conversely, recollection enables retrieving associations between arbitrarily linked information, such as associations between photographs of different persons (inter-item associations). By measuring event-related brain potentials (ERPs), we obtained a double dissociation of familiarity and recollection that strongly favors dual-process accounts of recognition memory: the electrophysiological correlate of familiarity was significantly larger for intra- than for inter-item associations. Conversely, the electrophysiological correlate of recollection was significantly larger for inter- than for intra-item associations.