Abstract: Conceptual priming and familiarity are hot spots of researches on neuro-mechanisms of implicit and explicit memory. Supporters of dual-process theories put forward that brain potentials at pre-frontal areas between 300 and 500ms (FN400) are associated with familiarity. However, supporters of single- process theories think that studies supporting FN400 as index of familiarity did not take into account the contamination of conceptual priming on explicit memory. Through a series of studies, Paller and his colleagues proved that FN400 is associated with conceptual priming but not familiarity and that familiarity is indexed by brain potentials at parietal areas between 500 and 800ms (LPC). So far, there are still debates on the nero-mechanism of familiarity and conceptual priming. Further researches should explore new methods to dissociate familiarity and conceptual priming. The neuro-mechanism of effects of fluency on familiarity should also be investigated.

Key words: familiarity, conceptual priming, FN400