Multiple ways to the prior occurrence of an event: An electrophysiological dissociation of experimental and conceptually driven familiarity in recognition memory

►Familiarity contributes to associative recognition memory, when the to-be-associated stimuli are unitized at encoding. ►Familiarity assessment is not a unitary process and can be multiply determined. ►Task demands and event characteristics can promote the assessment of conceptually driven familiarity (as reflected in an early parietal ERP old/new effect) or experimentally-induced increments of familiarity (as reflected in an early mid-frontal old/new effect). ►The ease of unitization at study modulates conceptually driven familiarity but not experimental familiarity.