Implicit sequence learning: Effects of level of structure, adult age and extended practice. Psychology and Aging

The influence of structure and age on sequence learning was investigated by testing 24 young and 24 older participants for 10 sessions in an alternating serial response time task in which pattern trials alternated with random trials. Individuals encountered lag-2 or lag-3 structure, and learning was measured by the difference (in response time and accuracy) between pattern and random trials. Both ages learned lag-2 structure, but the young learned more than the older participants. Only the young people learned lag-3 structure, and they did so more slowly and to a lesser degree than they learned lag-2 structure. These age deficits in higher order sequence learning after extended practice are consistent with simultaneity theory and with theories positing that age-related deficits in neuromodulation lead to less distinctive representations. Implicit learning occurs when people become sensitive to co-variations in the environment without intending to do so and without becoming aware of what they have learned (e.g., Cleere-mans, Destrebecqz, & Boyer, 1998). Despite burgeoning interest in implicit learning over the past decade, there has been relatively little research on its aging (for a review see Prull, Gabrieli, &amp