Walking variability and working-memory load in aging: a dual-process account relating cognitive control to motor control performance.
Effects of cognitive activities on walking variability are poorly understood. We parametrically manipulated working-memory load by using an n-back task in 32 younger adults and 32 older adults walking on a treadmill at self-selected speed. We found no dual-task costs for cognitive performance. Stride-to-stride variability was lower when participants performed an easy working-memory task than when they walked without cognitive tasks. Increasing working-memory load from 1-back to 4-back produced decreasing variability of stride time and stride length in younger but not in older adults. Extending the 2006 dual-process account proposed by Huxhold, Li, Schmiedek, and Lindenberger, we conclude that normal aging alters the trade-off between the effects of focus of attention and resource competition on walking variability.
Center for Lifespan Psychology, Max Planck Institute for Human Development, Lentzeallee 94, Berlin, Germany. loevden@mpib-berlin.mpg.de
Martin
M
Lövdén
Sabine
S
Schaefer
Anna E
AE
Pohlmeyer
Ulman
U
Lindenberger
D000328:Adult; D000368:Aged; D000375:Aging; D001288:Attention; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology*; D008570:Memory, Short-Term; D009069:Movement Disorders / Q000175:diagnosis / Q000453:epidemiology*; D033262:Narration; D009483:Neuropsychological Tests; D011596:Psychomotor Disorders / Q000175:diagnosis / Q000453:epidemiology*; D012720:Severity of Illness Index; D013028:Space Perception; D013998:Time Perception; D016138:Walking