aging ch4

Neuroimaging Techniques

Structural and Functional

Structural neuroimaging

● Provides detailed about the structure of the brain ● Examples - x-rays, CT scans

Functional neuroimaging

● Provides information about brain activity ● fMRI used most widely

What Do Neuroimaging Studies Tell Us?

● Older adults activate more and different areas of the brain than younger adults when doing the same cognitive tasks. ○ These findings challenge the prevailing idea that specific brain regions control specific brain functions.

THEORIES ● HAROLD

the level of bilateral activations in the prefrontal cortex of aging brains demonstrates compensatory processes for numerous cognitive tasks

THEORIES ● CRUNCH

more activation is seen on easy tasks, while equal or less activation is seen on difficult tasks for older adults

THEORIES ● STAC

integrative account of the different theories, continuous functional reorganization

Several factors that contribute to changes in cognitive abilities with age

○ a decline in sensory abilities ○ the effect of motor speed on paper-pencil measures of cognitive speed ○ the impact on level of education and physical activity ○ the molecular biological changes that occur with age ● However, these factors have seldom been implicated in any single theoretical model of cognitive aging.

The frontal lobes, hippocampus (in the temporal lobe), and parietal lobes are particularly vulnerable to age-related decline, affecting cognitive abilities such as

executive functions and episodic memory.

White Matter

○ Consists of bundles of axons that connect areas of grey matter ○ Myelin provides electrical insulation to the axons ○ White matter decline has been identified as a clinical marker for several diseases

● Declines in dopamine

○ associated with short term memory

● Changes in processing serotonin

○ associated with cognitive decline and dementia

● Declines in acetylcholine

○ associated with Alzheimer's disease

The size, number and density of

blood vessels also change with age.

Cognitive Reserve (CR)

Two people with similar levels of brain pathology can show significantly different levels of function

•Education • Complex work experience • Active lifestyle • Bilingualism Acts as a buffer against

cognitive decline

Higher CR is related to less severe or delayed

clinical manifestations of several diseases

Sensory Memory

● Initial process of storing information ● Most studied are iconic, echoic, and tactile ● Sensory memory lasts only a few hundred milliseconds ● Does not typically change with age.

Research suggests that the central executive is the aspect of working memory most

vulnerable to agerelated declines

Memory Changes in Attention with Age

General slowing of processing speed, Greater difficulties doing more than one thing at once, Simple tasks no change, Complex tasks more errors.

Why does working memory change with age?

●Reduction in processing resources ●Reduction in processing speed ● Difficulty inhibiting irrelevant information ●Declines often depend on task complexity

Two primary forms of long-term memory

Episodic memory, Semantic memory

● Episodic memory

Responsible for storing personally experienced information about a specific event (e.g., your first day of school; what you had for breakfast).

● Semantic memory

A part of long-term memory responsible for storing information about the world (e.g., the names of colours, sounds of letters, capitals of countries in the world, and other basic facts).

Episodic memory problems can occur as a result of

deficiencies in encoding, storage, or retrieval.

○ Encoding

The initial process of getting information into the memory system for storage and later retrieval.

○ Storage

The ability to retain information in the memory system over time.

○ Retrieval

The ability to get information out of the memory system when needed.

● Two ways to measure age differences in episodic memory

Recall, Recognition

○ Recall

remembering information without hints or clues

○ Recognition

selecting previously learned information from among several items

Age differences in semantic memory

● There appear to be very few changes in this ● However, access seems to be a problem

Word-Finding Difficulties

● Vocabulary tends to maintain or accumulate over the lifespan ●What are some changes that do occur?

● Under-accommodation

○ When a communication partner fails to consider how normal age-related changes affect speaking and listening

● Over-accommodation

○ When a communication partner relies on negative stereotypes of the older adult to guide communication

Elderspeak

● A type of over-accommodation

Communication Predicament of Aging Model

● based on the assumption that speakers make accommodations in their communication style based on observations of the listener, Can often find this kind of speech in long-term care facilities.

There are many different theories of intelligence

Psychometric approach, G a single, general factor, Primary mental abilities, Multiple intelligences, Fluid and Crystallized Intelligence, Crystalized intelligence

• Psychometric approach

assumes that intelligence is something that can be measured in greater or lesser amounts

• G a single, general factor

Spearman

Primary mental abilities

intelligence consisted of 7 primary abilities, organized into clusters of secondary mental abilities.

• Multiple intelligences

Gardner outlined 8 types of intelligence that are not all focused on “book smarts”, but include concepts previously thought to be talents.

Fluid and Crystallized Intelligence (Horn & Cattell) ● Secondary abilities

○ Fluid Intelligence ○ Independent of acquired knowledge and experience ○ Perceptual reasoning scales measure this ● Crystalized intelligence

The CHC model of intelligence

has had tremendous influence over the study of intelligence. Many psychologists today believe that the CHC model of intelligence is the most comprehensive and empirically supported psychometric theory of the structure of cognitive abilities to date

Does performance on intelligence tests change with age?

● Controversial subject ○ Problems in measurement ● Seattle Longitudinal Study ○ No uniform pattern of age-related decline ○ Support for Classic Aging pattern but declines were much less

“Does intelligence change with age?”

we cannot separate this question from the cohort from which the participants are based, as illustrated in the figure. This also shows the issue with making cross-sectional comparisons, as older and younger cohorts may have had different “start points”

Health in late life can impact performance on IQ tests

● Lower IQ scores are associated with cardiovascular disease, obesity, and stroke, cancer, and a host of other diseases ● Other factors related to the maintenance of intelligence in late life include…

Two main types of training programs

● Cognitive training programs ○ directed practice of specific cognitive tasks ● Cognitive stimulation programs ○ designed to increase general cognitive functioning Findings are mixed due to several methodological issues.

Effects of Lifestyle Factors on Cognition

● Regular physical activity improves cognitive function ● The effects of diet (Mediterranean) Get active and eat well!

Decision Making

● Limited evidence suggests that problem solving ability declines with age ● Could be due to declines in fluid ability ● Less certain about the role of crystalized ability ● Relevance matters

In post-formal thought

● Truth varies from situation to situation ● Solutions must be realistic ● Ambiguity and contradiction are the rule ● Emotion and subjective factors usually play a role in thinking A systematic progression of reflective judgement.

Wisdom

● No single consensus definition ● Six commonly included components ●Distinction also made between personal wisdom and general wisdom

Three-Dimensional Model of Wisdom

● Cognitive dimension ● Reflective dimension ● Affective dimension

● Cognitive dimension

A deep and thorough understanding of both interpersonal and intrapersonal aspects of life

Reflective dimension

Profound insight as well as selfawareness and ability to self-reflect or perceive events from multiple viewpoints

Affective dimension

Empathy, social connectedness, and generativity