Ageing + Cognition

Question 1

What is a longitudinal study?

Answer 1

• Recruit representative sample + test repeatedly over time
• Cohort studies
• Investigate number of variables

Question 2

What are the advantages of a longitudinal study?

Answer 2

• Effect of age can be determined on individual bases

- Useful in pinpointing disease precursors

Question 3

What are the disadvantages of longitudinal studies?

Answer 3

• Expensive
• Time consuming
• High drop out
• Practice effects (get better at same test)

Question 4

What is a cross-sectional study?

Answer 4

• Recruit diff. groups of people

- Sample across age range, with each being tested once

Question 5

What are the advantages of cross-sectional studies?

Answer 5

• No re-testing
• Quicker
• Less expensive
• Low drop out rates

Question 6

What are the disadvantages of cross-sectional studies?

Answer 6

• Performance not related to earlier/future performance

- Cohort effects (born at different times so changes in diet, education, social factors)

Question 7

Which type of study underestimates age-related changes?

Answer 7

Longitudinal

Practice effects

Question 8

Which type of study overestimates age-related changes?

Answer 8

Cross-sectional

Cohort effects

Question 9

What type of memory expands with age?

Answer 9

Semantic memory - vocab + historical facts

Also retain ability to learn + retain new skills

Question 10

What are the effects of ageing on cognition?

Answer 10

1. General mental slowing hypothesis = decreased processing speed due to ageing NS
2. Common cause hypothesis = brain deteriorating with other bodily systems
3. Inhibition deficit hypothesis = reduced capacity to inhibit irrelevant stimuli > linked with central executive reduced stroop test

Question 11

What happens to different parts of the brain as it ages?

Answer 11

Overall - Shrinks
Ventricles - Expands 
Frontal lobes - Shrinks most rapidly 
Temporal lobes - Shrinks slowly 
Hippocampus - Shrinks slowly then accumulates 
Occipital lobes - Shrinks slowly

Question 12

What area of the brain is most vulnerable to ageing?

Answer 12

Frontal white matter

Question 13

What are the theories of neurocognitive ageing?

Answer 13

1. Impaired function of prefrontal cortex - normal ageing
2. Disruption of medial temporal lobe memory system (inc. hippocampus) - may be pathological ageing, leads to episodic LTM impairment

Question 14

Define Dementia

Answer 14

Progressive deterioration of previously acquires intellectual abilities that interferes with social/occupation functioning

Question 15

What is the diagnostic criteria for Alzheimers?

Answer 15

• Cognitive deficits in memory, lang, action control, judgement, perception, executive function
• Preserved awareness of environment
• Impaired social function
• Continued cognitive decline

Question 16

What pathological changes are seen in Alzheimers?

Answer 16

• Build up of B amyloid peptide > deposited as neurofibrillary tangles (NFT)
• Accompanied by neuronal loss
• Pathological diagnosis rests on amyloid plaques + NFT’s

Question 17

Which memory is impaired most in Alzheimers?

Answer 17

• Episodic and also semantic but less and at later stage
• Explicit worse than implicit (which can actually improve)

Anterograde amnesia = cognitive hallmark of AD

Question 18

What is the best predictor of explicit memory impairment in AD?

Answer 18

Hippocampal atrophy

Question 19

What is the best predictor of semantic memory impairment in AD?

Answer 19

Distributed neocortical atrophy

Question 20

What causes vascular dementia?

Answer 20

Lack of O2 to areas of brain = neuronal death