Alternating training improves motor learning

(Baltimore, MD) — Learning from one's mistakes may be better than practicing to perfection, according to a new study appearing in the October 19 issue of The Journal of Neuroscience. Researchers from the Kennedy Krieger Institute found that forcing people to switch from a normal walking pattern to an unusual one — and back again — made them better able to adjust to the unusual pattern the following day. The findings may help improve therapy for people relearning how to walk following stroke or other injury.

Previous studies in the lab of Amy Bastian, PhD, Director of Motion Analysis Laboratory at Kennedy Krieger Institute, found that walking on a split-belt treadmill — which forces one leg to move at a faster speed — can help correct walking deficits in children and adults with weakness on one side of the body caused by stroke, brain damage, or other conditions. In the new study, Bastian and her colleagues found healthy adults forced to alternate between learning and unlearning an unusual walking pattern on a split-belt treadmill relearned the pattern faster the next day.

"The standard approach to helping stroke patients relearn walking and other motor skills is to tell them how to move better, and then practice it over and over again," Bastian said. "The results of our study suggest that the most effective approach might be to repeatedly challenge patients with new training situations."

In the current study, the researchers trained 52 healthy adults to walk on a split-belt treadmill. One group received 15 minutes of constant exposure to belts moving at different speeds, while another — the switch group — walked on belts that alternated between different speeds and identical speeds. Twenty-four hours later, both groups returned to the treadmill to walk on the belts moving at different speeds. The adults in the switch group relearned how to resume the unusual walking pattern faster than those who had constant exposure to different speeds.

"The people in the switch group 'learned to learn' by experiencing more of the awkward, limping leg pattern that occurs right after a switch in speeds," Bastian said.

Contrary to the researchers' predictions, they also found practicing a completely different walking pattern did not interfere with the ability to relearn the first one. A third group practiced walking on a split-belt treadmill that forced the right leg to move faster for 15 minutes, followed by 15 minutes in which the left leg moved faster. When they returned the next day, they too relearned the initial walking pattern slightly faster than those who trained only on a single pattern.

The research was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development.

Internationally recognized for improving the lives of children and adolescents with disorders and injuries of the brain and spinal cord, the Kennedy Krieger Institute in Baltimore, MD serves more than 16,000 individuals each year through inpatient and outpatient clinics, home and community services and school-based programs. Kennedy Krieger provides a wide range of services for children with developmental concerns mild to severe, and is home to a team of investigators who are contributing to the understanding of how disorders develop while pioneering new interventions and earlier diagnosis. For more information on Kennedy Krieger Institute, visit www.kennedykrieger.org.

The Motion Analysis Laboratory at Kennedy Krieger Institute studies performance and learning of reaching and walking movements in healthy adults and children, and in different patient populations including: adults and children with cerebellar damage, adults with hemiparesis from stroke, adults with multiple sclerosis or adrenomyeloneuropathy, children with hemispherectomy, children with cerebral palsy and children with autism. All studies are designed to test specific hypotheses about the function of different brain areas, the cause of specific impairments and/or the effects of different interventions.