Cognitive Functions & Decline In Healthy Ageing- Lecture 7 Flashcards
Implications of studying impact of normal ageing
- Increasingly aged population: longer life expectancy- medical advancements
- Cognitive decline is a major health and social issue > causes great anxiety in older generation»_space; major links with Dementia
Effect of normal ageing on Vision
- Pupil decreases in size and is less sensitive to light (age problems more evident in less optimal conditions)
- Struggle adapting to the dark (driving becomes difficult)
- Visual impairments etc. (listed below)
Types of visual impairments
Cataracts Diabetic retinoplasty Retinitis pigmentosa Glaucoma Macular-degenration
Effect of normal ageing on hearing
- 90% of over 65s with at least mild impairments
- High sound frequencies affected earlier than low frequencies
- Men more vulnerable than women
Effect of normal ageing on Smell and Taste
- Decline in discrimination of odours (especially pleasant odours)
- Impaired food recognition
Healthy vs pathological ageing
- The line between healthy and unhealthy ageing is difficult to distinguish.
- The diagnostic criteria is uncertain-> no absolute threshold of cognitive decline
- Cog. impairments can sometimes hide pathology->similar brain abnormalities in normal ageing and Alzheimer’s
- Methodological issues when conducting lifespan research= requires careful consideration of methods when interpreting outcomes
Longitudinal Designs of studying normal ageing
Pros & Cons
+Identifies age related changes
+Unaffected by cohort effects (ptps. will most likely be from same cohort)
- Non-random drop out
- Expensive, complex, time consuming
- Repeated testing effects
- Time of measurement effects
Cross-sectional design of studying normal ageing
Pros & Cons
+Identifies age group differences
+Inexpensive, quick simple to design and conduct
+No time measurement effects
+No practise effects
- Cannot measure age change, only age differences- get a snapshot rather than whole story
- Cohort effects may be present
Sequential Design of studying normal ageing
Pros & Cons
+All pros of both longitudinal and cross sectional designs
- Very complex, expensive and time consuming
- Missing data from one participant at any stage of study may mean eliminating them
Cognitive Functioning affected by normal age
- Intelligence
- attention
- Working memory
- processing speed
- long term memory
Intelligence and ageing:
Cattell (1941)
2 types of Intelligence:
-Fluid intelligence: solve problems and adapt to novel environments
Largely hereditary
-Crystalised intelligence: application of formal knowledge
Depends on culture, family education- sensitive to motivation, practise and exercise
Changed to IQ within ageing
-Fluid IQ declines
-Crystallised IQ maintained
BUT only in cross-sectional design
In longitudinal it appears that :
-Both fluid and crystallised are stable
Mackintosh (2011)
> Crystallised IQ shows gradual increase and is then largely stable (although it could decline much later in life)
—->not a large difference between 25 yrs and 70 yrs
> Fluid IQ starts to decline earlier- in middle age
- IQ at 11 can accurately predict IQ at 80
- –>Correlation is high but not perfect > there are factors that may increase or decrease someone’s IQ
Attention and Ageing
Older adults show impairments in attentional tasks such as stroop and visual searching tasks
—>impairment increases, the more complex the task becomes (Macleod, 1999)
VISUAL SEARCH TASKS
-more errors, slower responses
-Greater difficulty of detecting target
Both bottom up and top down attention affected, but top down more-so affected by ageing
MEMORY affected by normal ageing
Working Memory
‘Conscious memory, our ability to retain and manipulate information online’
STM capacity limited-
-verbal span: 5.8-6.6 digits
-Spatial span: 4.7-5.1 spaces
> Effect is more pronounced in more complex working memory processing tasks with added attention and manipulation requirements
