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

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

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

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

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

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.

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.

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

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!!!

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

So—What Do We “Know” About:

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

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:….

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

Prospective Memory—remembering to perform some 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.

What About Intelligence?

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

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

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

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

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

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?

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

“…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

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

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

The Processing Approach—Craik ‘86 Argues in terms of PROCESSES rather than structures. Interactional in nature. retrieval x x xThe x x Individual

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

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

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

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