TY - JOUR
T1 - Intraindividual variability in executive functions but not speed of processing or conflict resolution predicts performance differences in gait speed in older adults
AU - Holtzer, Roee
AU - Mahoney, Jeannette
AU - Verghese, Joe
N1 - Funding Information:
Funding This research was supported by the National Institutes on Aging (R01AG036921; PI: R.H.).
PY - 2014/8
Y1 - 2014/8
N2 - Background. The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single-and dual-task conditions. Methods. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single-and dual-task conditions. The flanker task was used to assess EF. Results. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19-38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate =-.606; 95% CI =-1.11 to-.10). In unadjusted analyses, the three EF measures were related to gait speed in single-and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B =-.901; 95% CI =-1.557 to-.245). Conclusion. Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed.
AB - Background. The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single-and dual-task conditions. Methods. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single-and dual-task conditions. The flanker task was used to assess EF. Results. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19-38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate =-.606; 95% CI =-1.11 to-.10). In unadjusted analyses, the three EF measures were related to gait speed in single-and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B =-.901; 95% CI =-1.557 to-.245). Conclusion. Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed.
KW - Aging
KW - Cognitive control
KW - Dual tasks
KW - Mobility
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U2 - 10.1093/gerona/glt180
DO - 10.1093/gerona/glt180
M3 - Article
C2 - 24285744
AN - SCOPUS:84904020489
SN - 1079-5006
VL - 69
SP - 980
EP - 986
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
IS - 8
ER -