Nonconscious priming after 17 years: invulnerable implicit memory?

Individuals who saw pictures for 1 to 3 s in the laboratory were tested 17 years later by mail. Identification rates were significantly higher for fragments from these previously exposed targets than for novel fragments, whereas the same stimuli evoked no differences in control groups that had not been previously exposed to the pictures. Priming--the memorial advantage conferred by prior perceptual experience--was stable over the years (r= .51). Priming was dissociated from episodic memory, in that it was present even in subjects who reported no conscious recollection of their participation in the original laboratory session. These findings suggest that the perceptual representation system is an invulnerable memory system functioning below conscious awareness.