Associations between physical and cognitive function in healthy older adults

Restricted (Penn State Only)
Author:
Sprague, Briana Nicole
Graduate Program:
Human Development and Family Studies
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
February 28, 2019
Committee Members:
  • Lesley A. Ross, Dissertation Advisor
  • Lesley A. Ross, Committee Chair
  • Alyssa A. Gamaldo, Committee Member
  • David N. Proctor, Committee Member
  • Stephanie Trea Lanza, Outside Member
Keywords:
  • physical function
  • older adults
  • cognition
  • cognitive training
  • subjective memory
Abstract:
There is a positive relationship between objective physical and cognitive function in older adults. The magnitude of the subjective relationship across older adulthood is unknown, and understanding relationship (in)stability across adulthood has implications for statistical modeling and clinical practice. Another gap in the literature is the long-term effect of cognitive interventions on physical function. Emerging literature identifies cognitive interventions as promising for ameliorating late-life physical function degradations, but most studies are underpowered and include immediate posttest only results. This dissertation consists of two studies that address these limitations in a large sample of healthy older adults. Study 1 examined the cross-sectional relationship between subjective physical and memory function using a flexible extension of regression, time-varying effect modeling. Study 2 explored the 10-year effects of three cognitive training programs (speed of processing, memory, or reasoning) on multiple measures of objective physical function (grip strength, Digit Symbol Copy, and Turn 360). A secondary aim was to examine whether the training benefits were equivalent across various baseline psychosocial factors and baseline subjective bodily pain. Both studies utilized a large (N = 2,802) sample of healthy older adults from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial with 10 years of available data. This dissertation demonstrated that subjective physical and memory function were related and the relationship was stable across older adulthood (Study 1). Additionally, cognitive training did not attenuate age-related decline in physical function across 10 years in intention-to-treat (ITT) analyses (Study 2). Baseline factors did not consistently moderate this relationship, demonstrating that no subgroups were more susceptible to training gains on physical functioning across ten years (Study 2).