Adaptive task prioritization in aging: selective resource allocation to postural control is preserved in Alzheimer disease

Am J Geriatr Psychiatry. 2006 Jan;14(1):52-61. doi: 10.1097/01.JGP.0000192490.43179.e7.


Objective: With age, the performance of multiple tasks decreases, a pattern exaggerated in Alzheimer disease (AD). At the same time, recent research, based on adaptive theories of healthy aging, indicates a preference of older adults to allocate resources toward tasks of higher immediate value (e.g., postural control). This study investigated whether such models also hold for pathologic cognitive aging.

Method: Using a dual-task paradigm, the authors combined a working memory with a postural control task under easy and difficult conditions in patients with AD, older adults, older adults low on performance on a cognitive marker test, and young adults (N = 40). Participants repeatedly performed a cognitive and a postural control task both simultaneously and in isolation over the course of eight sessions.

Results: Consistent with earlier studies on divided attention in age and AD, the authors found large dual-task performance decrements with age and more so in AD. When not challenged, patients with AD showed large performance decrements under dual-task conditions in both postural control and working memory. With increasing difficulty in the postural control task, however, older adults, and more so patients with AD, maintained a high level of functioning in postural control, as compared with working memory.

Conclusion: The findings indicate that the theory of selective optimization with compensation extends to pathologic aging and have broad implications for models of dual-task performance and executive control in aging and AD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aging / psychology*
  • Alzheimer Disease / psychology*
  • Analysis of Variance
  • Attention / physiology
  • Cognition / physiology
  • Female
  • Humans
  • Male
  • Memory, Short-Term / physiology
  • Middle Aged
  • Postural Balance / physiology*
  • Posture / physiology*
  • Psychomotor Performance / physiology
  • Resource Allocation / statistics & numerical data*
  • Task Performance and Analysis*