title: Increased Adaptation Rates and Reduction in Trial-by-Trial Variability in Subjects with Cerebral Palsy Following a Multi-session Locomotor Adaptation Training.
abstract: Cerebral Palsy (CP) results from an insult to the developing brain and is associated with deficits in locomotor and manual skills and in sensorimotor adaptation. We hypothesized that the poor sensorimotor adaptation in persons with CP is related to their high execution variability and does not reflect a general impairment in adaptation learning. We studied the interaction between performance variability and adaptation deficits using a multi-session locomotor adaptation design in persons with CP. Six adolescents with diplegic CP were exposed, during a period of 15 weeks, to a repeated split-belt treadmill perturbation spread over 30 sessions and were tested again 6 months after the end of training. Compared to age-matched healthy controls, subjects with CP showed poor adaptation and high execution variability in the first exposure to the perturbation. Following training they showed marked reduction in execution variability and an increase in learning rates. The reduction in variability and the improvement in adaptation were highly correlated in the CP group and were retained 6 months after training. Interestingly, despite reducing their variability in the washout phase, subjects with CP did not improve learning rates during washout phases that were introduced only four times during the experiment. Our results suggest that locomotor adaptation in subjects with CP is related to their execution variability. Nevertheless, while variability reduction is generalized to other locomotor contexts, the development of savings requires both reduction in execution variability and multiple exposures to the perturbation.
authors.affiliation: Department of Biomedical Engineering, Ben-Gurion University of the NegevBeer-Sheva, Israel; Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, BaltimoreMD, USA; Zlotowski Center for NeuroscienceBeer-Sheva, Israel.
authors.forename: Firas
authors.initials: F
authors.lastname: Mawase
authors.affiliation: Zlotowski Center for NeuroscienceBeer-Sheva, Israel; Department of Physical Therapy, Ben-Gurion University of the NegevBeer-Sheva, Israel.
authors.forename: Simona
authors.initials: S
authors.lastname: Bar-Haim
authors.affiliation: Zlotowski Center for NeuroscienceBeer-Sheva, Israel; Department of Physical Therapy, Ben-Gurion University of the NegevBeer-Sheva, Israel.
authors.forename: Katherin
authors.initials: K
authors.lastname: Joubran
authors.affiliation: Department of Biomedical Engineering, Ben-Gurion University of the NegevBeer-Sheva, Israel; Zlotowski Center for NeuroscienceBeer-Sheva, Israel.
authors.forename: Lihi
authors.initials: L
authors.lastname: Rubin
authors.affiliation: Department of Biomedical Engineering, Ben-Gurion University of the NegevBeer-Sheva, Israel; Zlotowski Center for NeuroscienceBeer-Sheva, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Karniel
authors.affiliation: Zlotowski Center for NeuroscienceBeer-Sheva, Israel; Department of Brain and Cognitive Sciences, Ben-Gurion University of the NegevBeer-Sheva, Israel; Department of Physiology and Cell Biology, Ben-Gurion University of the NegevBeer-Sheva, Israel.
authors.forename: Lior
authors.initials: L
authors.lastname: Shmuelof
keywords: adaptation; asymptotic performance; execution variability; gait; rehabilitation