Evaluating the relationship between explicit and implicit knowledge in a sequential reaction time task

Can knowledge underlying a simple perceptual-motor skill be unconscious? Th ree experiments (a) trained participants on a 4-choice reaction time (RT) t ask in which the stimulus on each trial was determined by a repeating 12-el ement sequence and (b) studied the extent to which participants' knowledge of this sequence was implicit, that is, unavailable for conscious access. P articipants proved via an indirect test to have acquired knowledge of the s equence, because their RTs increased when the sequence was changed. To eval uate whether this knowledge was consciously accessible, participants were a sked to perform an "objective" free-generation or recognition test of seque nce knowledge. Results show that sequence knowledge is fully accessible on these objective tests. Moreover, it is demonstrated in this procedure that old-new recognition cannot be explained by unconscious attribution of perce ptual-motor fluency. The question is raised whether distinct implicit (proc edural) and explicit (declarative) forms of knowledge are acquired when par ticipants learn a perceptual-motor skill.