IMPLICIT LEARNING OF UNIQUE AND AMBIGUOUS SERIAL TRANSITIONS IN THE PRESENCE AND ABSENCE OF A DISTRACTOR TASK

Three experiments investigated the effects of task load, time of secondary task onset, and response-stimulus time interval on direct and indirect measures of learning in the M. J. Nissen and P. Bullemer (1987) task. Experiment 1 demonstrated that both unique and ambiguous serial transitions can be learned in the absence and presence of an attentional distractor task. Experiment 2 showed that the time of secondary task onset affects the degree to which unique and ambiguous serial transitions are learned. Experiment 3 demonstrated that the learning of a sequential transition is affected by the length of the time interval between the response to a stimulus and the presentation of the next stimulus. The findings replicate and extend results reported by A. Cohen, R. I. Ivry, and S. W. Keele (1990) and provide important empirical constraints for a process model of implicit serial learning.