Cognitive Aging

1. Cognitive Aging Based on Information in: Surprenant, A.M. & Neath, I. in Wilmoth & Ferraro, Gerontology: Perspectives & Issues

2. “…the entire person needs to be considered in order to develop a comprehensive theory of cognitive aging” (p. 89).

3. Cognitive Aging Includes: • Memory • Attention • Language • Intelligence • Brain changes • “everyday functioning in familiar environments”

4. Approaches to Studying Cognitive Aging • Micro (Experimental) • Macro (Psychometric) • Simulation Modeling

5. Micro (Experimental) Approaches • Focus: “…describing specific tasks & processes that differ as a fx of age. • Strategy: ID a subtask that can be timed; present it as a decision-making task and time the outcome. • Design: Experimental with Age as the independent variable & Time as the dependent variable

6. Macro (Psychometric) Approaches • Focus: “…a broad range of cognitive processing abilities that vary with age.” • Design: Correlation or Psychometric techniques. Goal: To identify commonalities—i.e., “…fundamental cognitive abilities” that differ with age.

7. Simulation Modeling: A recent middle ground approach • The Advantage: Better deals with the complexity of the effects of aging on cognition—many factors, multiples interactions among them.

8. Study Designs: Cross-sectional • “…the performance of a group of individuals from one age range is compared to that of a group from another age range.” • Easiest to do, but ignores uncontrolled covariates, e.g. cohort effects, motivation, health status

9. Study Designs: Longitudinal • Follows individuals over time, testing them repeatedly—e.g., The Nuns’ Study; HRS • “…allows researchers to estimate individual changes in particular abilities rather than inferring changes based on group differences • Very costly!!!

10. Meta-Analysis • “…a tool for combining results from multiple experiments…to determine the true size of an effect.”

11. So—What Do We “Know” About:

12. Perceptual Deficits • “Both visual & Auditory processing abilities decline substantially as a fx of increasing age.” • Presbycusis-1/3 of 0ver-70 adults • Understanding speech in noise • “I can’t hear as fast as you talk.” • Light sensitivity; visual acuity; color vision; contrast sensitivity. • Possible Results: Limitation in activity & social function

13. Memory • A Matter of Great Concern; “…significant correlations between estimated memory ability and reports of depression.” • “Older adults perform worse than younger adults on memory tests in which there are few environmental cues.” Thus:….

14. Old people compared to younger-- • Worse on Recall tests; Equivalent on recognition • Worse on Explicit than Implicit tasks • Worse on tasks requiring active information manipulation and only slightly worse on measures of simple memory span

15. Prospective Memory—remembering to perform some action @ some future time • Types: Time-based tasks; Event-based tasks • Comparison: O.A. less well on time-based; no differences in event-based. • Generalization: “Environmental support” is important for maintaining max cog. Fx.

16. What About Intelligence?

17. Primary Mental Abilities (PMA’s) • Mathematical reasoning • Word fluency and appropriate usage • Verbal meaning/vocabulary level • Inductive reasoning • Spatial relations • Verbal memory (ability to retain/recall info) • Perceptual speed

18. Types of Intelligence? • Fluid: “tasks that involve quick thinking, info manipulation, activities involving allocation and reallocation of attention—rely mainly on fluid intelligence. • E.g.: tests of memory, spatial relations, abstract & inductive reasoning, free recall, mental calculations

19. Crystallized: “tasks that tap well-learned stills, language, & retrieval of well-learned material rely more on crystallized intelligence. • E.g.: verbal meaning, word association, social judgement, number skills

20. Differences with aging? • Decreases—Fluid Intelligence • No Decreases (actually some increases)—Crystallized Intelligence (Salthouse, et al)

21. Explanation? Some Alternatives: • 1) Slowed processing speed • 2) Lack of inhibitory control • 3) Perceptual processing resources (working memory capacity) reduction • 4) Perceptual processing efficiency reduction

22. Slowed processing speed: • Usually measured by reaction times. • Salthouse argues that decreases in speed underlie most of the “age-related” declines in cog. Fxing. • If so, the question becomes: What causes the slowing?

23. Inhibition and Control: • In short, performance deficits are due to a difficulty in inhibiting irrelevant information—which leads to: • Increased interference & • Reduced processing resources.

24. “…the processing account (ala Craik, et al—mid 80’s) better explains the pattern of data found in research on cognitive aging” (p. 98) • The Structuralist Tradition vs. • The Processing Approach

25. Structuralist Tradition: • Purpose of the science of Psych: • to analyze & describe basic elements of cognition & • Discover how they work

26. Structuralist, cont’d • Development: a process of maturation of structures in childhood and • Deterioration in late adulthood • Concept: “a partitioning of cognition”.

27. The Processing Approach—Craik ‘86 • Argues in terms of PROCESSES rather than structures. • Interactional in nature. • Environment Environment @ encoding @ retrieval x x x x x x x The x x Individual

28. The combination of the person, the task, and the environment are all needed to explain age-related changes in memory.

29. Declining Sensory Abilities as a Fx of Aging • “ It is possible that speed in processing slows because basic input processes result in impoverished input that then take more time to identify and interpret.” • Causality? There is a ‘chicken & egg’ problem

30. Biological Aspects of the Aging Brain • Areas of the Aging Brain—smaller, but not uniformly so. • Most change in frontal lobe

31. Can We Improve Cognitive Abilities? • It’s a mixed bag. • Fitness level and cognitive Fx? A highly qualified “probably”. • P.M. Schwirian. 10/30/08