The Influence of Inter-Event-Interval on Implicit Learning of Serial Patterns.

Abstract:
previous research we found age-related implicit learning deficits in a variation of the serial reaction time task in which predictable events alternate with random ones (Howard & Howard, 1997). The task is self paced in that the next event occurs a fixed period after a response. Two experiments investigated the possibility that older individuals' longer and more variable response times contributed to the learning deficit. In both experiments a group of "aged" young were compared to young controls over six days. The "aged" group experienced a random delay between their response and the next event to create an inter-event interval (IEI) which mimicked that experienced by the old in our earlier experiment. In the first experiment the mean and variance of the random delay was reduced daily to match the IEI of the old, whereas in the second experiment, the delay parameters were held at the first day values across the six days. The results revealed slower learning for the "aged" group in the first experiment and slower overall responding with equivalent learning for the "aged" people in the second. Overall, the results indicate that while longer and more variable IEIs influence learning, they cannot account for the age deficits observed previously.