title: Interacting effects of cognitive load and adult age on the regularity of whole-body motion during treadmill walking.
abstract: We investigated effects of concurrent cognitive task difficulty (n-back) on the regularity of whole-body movements during treadmill walking in women and men from 3 age groups (20-30, 60-70, and 70-80 years old). Using principal component analysis of individual gait patterns, we separated main (regular) from residual (irregular) components of whole-body motion. Proportion of residual variance (RV) was used as an index of gait irregularity. The gait in all age groups became more regular (reduced RV) upon introduction of a simple cognitive task (1-back), relative to walking without a concurrent cognitive task. In contrast, parametrically increasing working memory load from 1-back to 4-back led to age-differential effects, with gait patterns becoming more regular in those 20-30 years old, becoming less regular in those 70-80 years old, and showing no significant effects in those 60-70 years old. Our results support the dual-process account of sensorimotor-cognitive interactions (O. Huxhold, S.-C. Li, F. Schmiedek, and U. Lindenberger, 2006), with age-general effects of internal versus external attentional focus and age-specific effects of resource competition with increasing cognitive task difficulty.
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Julius
authors.initials: J
authors.lastname: Verrel
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Martin
authors.initials: M
authors.lastname: Lövdén
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Michael
authors.initials: M
authors.lastname: Schellenbach
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Sabine
authors.initials: S
authors.lastname: Schaefer
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development.
authors.forename: Ulman
authors.identifier: 0000-0001-8428-6453
authors.initials: U
authors.lastname: Lindenberger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D001288:Attention; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D004856:Postural Balance; D025341:Principal Component Analysis; D011597:Psychomotor Performance; D012691:Serial Learning; D016138:Walking / Q000523:psychology*; D055815:Young Adult