Implicit learning in a simple cued reaction-time task

Implicit learning tasks usually involve the learning of complex rules, Whil e this does reduce the likelihood of subjects becoming aware of the relatio nship to be learned, it also raises the possibility of explaining improved performance in terms of explicit processes. The current experiments are an attempt to develop a task which shows evidence of implicit learning, but wh ich involves the learning of a very simple rule and so avoids these alterna tive explanations. In two experiments, we exposed subjects to learning tria ls in which a target letter (or shape) was immediately preceded by a cue le tter (or shape) in otherwise random nine-letter (or 15-shape) sequences. In a test phase, subjects responded more quickly to cued than uncued targets if the learning phase had involved reliable cue-target pairings, but not fo llowing random control pairings. This was true of subjects who were classif ied as aware and those classified as unaware of the cue-target relationship . (C) 2000 Academic Press.