Objectives: Acquisition motor skill training in elderly is at great importance. The main purpose of this study was to compare young and elderly performance in serial reaction time task on different repeated and random conditions.

Methods & Materials: A serial reaction time task by using software was applied for studying motor learning in 30 young and 30 elderly. Each group divided randomly implicitly and explicitly into subgroups. A task 4 squares with different colors appeared on the monitor and subjects were asked to press its defined key immediately after observing it. Subjects practiced 8 motor blocks (4 repeated blocks, then 2 random blocks and 2 repeated blocks). Block time that was dependent variable measured and Independent-samples t- test with repeated ANOVA measures were used in this test.

Results: young groups performed both repeated and random sequences significantly faster than elderly (P<0.05). Older adults groups performed significantly faster random sequences than repeated sequences (P<0.05) whereas random and repeated sequences in young adult subgroups were not significantly different (P>0.05). Explicit older subgroup performed 7,8 blocks slower than 6 block with a significant difference (P<0.05).

Conclusion: Young adults discriminate high level performance than elderly in both repeated and random practice. Elderly performed random practice better than repeated practice.