Age-related deficits in motor learning and differences in feedback processing during the production of a bimanual coordination pattern

Learning and transfer of a new bimanual coordination pattern were investigated in a group of adolescents and elderly subjects. The pattern consisted of continuous horizontal flexion-extension movements with a 90 degrees phase offset between the upper limbs. All subjects practised the task under augmented feedback conditions, involving a real-time orthogonal display of both limb movements. Three different transfer test conditions were administered at regular intervals during practice, i.e. blindfolded, with normal vision, and with augmented visual feedback. Findings showed that the performance levels of the elderly group were lower than the group of adolescents and their rate of improvement was also smaller. The observed learning deficits in the elderly are hypothesised to be a consequence of a decreased capability to overcome the preferred coordination modes, as required for developing new coordination modes. This reduced capability to suppress prepotent response tendencies may reflect an age-related decrease in the efficiency of inhibitory processes in the central nervous system and may be associated with changes in frontal lobe functioning.