The influence of the response-stimulus interval on implicit and explicit learning of stimulus sequence.

Three experiments investigated the influence of the response-stimulus interval (RSI) on implicit and explicit learning of stimulus sequences. Participants responded to numerals presented in predetermined positions with alternating long and short RSIs. Half of the participants were instructed explicitly to learn the position sequence. In the transfer phase of Experiments 1 and 2, changing RSI patterns reduced the expression of incidental and intentional learning of position sequence. In Experiment 3 the position sequence was transformed, except that sub-sequences demarcated by long RSIs remained unchanged; this greatly reduced the expression of intentional learning, and slightly reduced that of incidental learning. These results indicate that in implicit learning, stimulus sequences are learned under the constraints of RSIs, whereas in explicit learning, learning independent of RSIs, as well as learning constrained by RSIs, occurs.