Abstract
Introduction: Many perceptual-motor tasks require rhythmic movements of limbs, pendulums, or display stimuli, with specific relative timing. People can generally only produce two stable coordination patterns without training: 0° and 180°. Others (e.g. 90°) usually have to be learned. Surprisingly, there are no major studies of rhythmic coordination learning across the lifespan. As part of a larger study, here we compare the learning of younger (20 years) and older (60, 70, 80 years) adults. Method: We presented two vertically displaced white dots against a black background. The computer controlled the top dot and the participant controlled the bottom dot via a joystick. Sessions involved the target phase relationship being displayed before participants attempted to produce the same coordinative pattern. There were three assessment sessions (Baseline, Post-training, Retention × 4 trials = 12 total) with 0°, 180° and 90°, and five training sessions (10 trials) with only 90°. Feedback was provided in training by changing the person-controlled dot from white to green when the participant was moving at 90°± an error band that decreased as performance improved. Results: All groups improved significantly across training and this was generally retained post-training. Nonetheless, learning rates were different between groups and decreased with age, with the older adults also showing highly variable performance. The introduction of feedback immediately improved performance in the young but not older adults. Discussion: The older adults showed reduced learning rates although the age of steepest decline has yet to be determined. The immediate improvement of the young with the introduction of the green dot implies the feedback usefully constrained the state space and thus allowed them to become attuned to the relevant perceptual variables - and therefore learn rapidly. In contrast, feedback was less useful for the older participants suggesting the state space remained relatively unconstrained with the negative consequences reflected in the learning rates.