Deficits in sequence-specific learning (SSL) may be a product of Parkinson’s disease (PD) but this deficit could also be related to dopamine replacement. The purpose of this study was to determine whether dopamine replacement affected acquisition and retention of a standing Continuous Tracking Task in individuals with PD. SSL (difference between random/repeated Root Mean Square Error across trials) was calculated over 2 days of practice and 1 day of retention for 4 groups; 10 healthy young (HY), 10 healthy elders, 10 individuals with PD on, 9 individuals with PD off their usual dosage of dopamine replacement. Improvements in acquisition were observed for all groups; however, only the HY demonstrated retention. Therefore, age appeared to have the largest effect on SSL with no significant effect of medication. Additional research is needed to understand the influence of factors such as practice amount, task difficulty, and dopamine replacement status on SSL deficits during postural tasks.
Hayes, Hunsaker, Foreman, and Dibble are with the Dept. of Physical Therapy, Shultz and White the Dept. of Exercise and Sport Science, and Schenkenberg the Dept. of Neurology, University of Utah, Salt Lake City, UT. Schaefer is with the Dept. of Health, Physical Education, and Recreation, Utah State University, Logan, UT. Boyd is with the Dept. of Physical Therapy, University of British Columbia, Vancouver, BC, Canada. Dyer is with the Brookhaven National Laboratory, Upton, NY. Maletsky is with Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS.