Implicit Learning in a Simple Cued Reaction-Time Task

Implicit learning tasks usually involve the learning of complex rules. While this does reduce the likelihood of subjects becoming aware of the relationship 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 which involves the learning of a very simple rule and so avoids these alternative explanations. In two experiments, we exposed subjects to learning trials in which a target letter (or shape) was immediately preceded by a cue letter (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 following random control pairings. This was true of subjects who were classified as aware and those classified as unaware of the cue–target relationship.