LEARNING VERSUS BEHAVIORAL EXPRESSION OF THE LEARNED - THE EFFECTS OFA SECONDARY TONE-COUNTING TASK ON IMPLICIT LEARNING IN THE SERIAL REACTION TASK

The replicated finding that implicit learning in the serial reaction t ask (SRT) is impaired when both the learning and the assessment of lea rning occur in the presence of a secondary tone-counting task has been interpreted as implying that the mechanism(s) underlying implicit seq uence learning require(s) attention in order to operate. However, in a lmost all studies, learning and the assessment of learning have been c onfounded. It is therefore unclear whether tone counting affects learn ing per se, the behavioral expression of the learned, or both. The goa l of the present research was to disentangle the effects of tone count ing on learning and the expression of the learned. In Exps. la and Ib, participants performed the Nissen and Bullemer SRT under different si ngle-task (ST) and dual-task (DT) practice schedules. In Exps. 2a and 2b, participants received different amounts of ST and DT practice. In all experiments, degree of implicit learning was then assessed under b oth ST and DT conditions. Results are consistent with the argument tha t primarily the expression of what has been learned and, to some exten t, implicit learning itself, are affected by tone counting. These find ings are easily understood in terms of specific interference mechanism s but are problematic for models that contain the assumption of an att entional learning mechanism.