Relationship between cognitive performance and mobility over the life course

Abstract

We studied cross-sectional, longitudinal and temporal associations between executive function and life-space mobility in old age. We assessed the association between intellectual ability in early adulthood and physical functioning in old age, and the association between early life motor development and cognitive performance in early old age. The participants of the first dataset were 157 persons aged 76-91 y who were followed up for two years as part of the Life-Space Mobility in Old Age study, and who took part in measurements on executive function (EF) implemented with the Trail Making Test and Life-Space Assessment. The second dataset comprised persons from the Helsinki Birth Cohort Study. Data on cognitive performance in early adulthood, assessed with The Finnish Defence Forces Basic Intellectual Ability Test at age 17-27 y, was available for 360 men. Data on age at first walking, used as a marker of early life motor development, and extracted from child welfare clinic records at age 6-24 months was available for 398 persons. Later life physical functioning was assessed twice at ten y intervals using self-reported Short Form 36 questionnaire, and later life cognitive performance with CogState computerized cognitive test in old age. People with better EF had higher life-space mobility. This was explained by better lower extremity functioning and absence of transportation difficulties (general linear model). Better EF at baseline predicted higher life-space mobility at the two-year follow-up whereas baseline life-space mobility did not predict EF at follow-up (cross-lagged model). Better intellectual ability in young adulthood predicted better physical functioning at mean age 71.4 (SD 2.2) y through better physical functioning at mean age 60.9 (SD 2.3) y (longitudinal path model). People who had learned to walk at an earlier age performed better in cognitive tests at mean age 64.2 (SD 3.0) y (linear regression model). Earlier attainment of motor skills and better early life intellectual ability may lead to better cognitive and physical functioning in older ages. Supporting EF may enhance maintenance of higher life-space mobility, an important correlate of good quality of life in old age.