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 investiga ted in a group of adolescents and elderly subjects. The pattern consisted o f continuous horizontal flexion-extension movements with a 90 degrees phase offset between the upper limbs. All subjects practised the task under augm ented 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 th eir 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 n ew coordination modes. This reduced capability to suppress prepotent respon se tendencies may reflect an age-related decrease in the efficiency of inhi bitory processes in the central nervous system and may be associated with c hanges in frontal lobe functioning.