Summary feedback schedules and speech motor learning in Parkinson's disease

By S.G. Adams, A.D. Page and M. Jog

This study examined the effects of two summary feedback practice schedules on the acquisition and retention of a novel speech motor skill in a group of 18 subjects with Parkinson’s disease (aged 55-73 years; 14 men). Subjects practiced producing the phrase 'buy bobby a poppy' within a 2400 ms time period (approximately two times slower speech rate than normal). Subjects produced 50 practice trials and received knowledge of results (KR) feedback about performance using a visual display. The absolute error between the target and actual utterance duration was used to measure performance accuracy and estimate motor acquisition. Subjects received a 20 trial retention test at ten minutes and two days following the practice session. The 18 subjects were randomized to two practice conditions. The 9 subjects that received summary feedback after every five trials were found to have significantly better 2-day retention scores than the 9 subjects that received summary feedback after every trial. These results are consistent with previous limb motor learning studies. It appears that there may be common motor learning principles involved in the acquisition and retention of novel speech and limb motor skills in normal and Parkinsonian subjects.