LB, Ageing, WEEK 5 Flashcards
1
Q
Why talk about ageing?
A
- Greater interest in ageing because over the last century many factors have increased life span (e.g. better healthcare)
- The graph shows countries who have increased life expectancy > expected that people born after 2000 will live to 100 years
- Lifespan is increasing but the problem is that health span is not keeping up > lifespan = how long you are alive, health span = how long you live healthily
- Healthy ageing is defined as being able to live independently + being functional at your daily life activities > gap between lifespan and health span is increasing
- This is why research identifying strategies for maintenance of cognitive and brain health in older age has become increasingly important
2
Q
Shifts motivating interest in ageing
A
- Today, 1 in 10 people are over 60 years old, by 2050, 1 in 5 people will be over 60 years old (in developing countries) > big shift
People aged over 60 will outnumber children in the category 0-14 by 2050 > by 2050 the amount of over 60 year olds will double, surpassing amount of 0-14 year olds.
3
Q
Ageing is not equal
A
- Women tend to live longer than men > women have a higher life expectancy and a higher healthy life expectancy
- Life expectancy differs based on whether you are in a high or low income country as well. > graph shows percentage of people over 60 in low, middle and high income countries. Can see high income countries have most people over 60
4
Q
What causes most deaths?
A
- Common causes of death from ageing include heart disease, stroke, cancer etc..
Importantly, Alzheimer’s disease is becoming more prevalent as a cause of death now that lifespan is increasing > as lifespan increases so does likeliness of developing Alzheimer’s
5
Q
Healthy ageing impacts cognition
A
- WHO defines healthy ageing as not being fully free of disease but being functional in daily life independently.
- Healthy ageing does not mean there will be NO cognitive decline > means you may not have Alzheimer’s or dementia but there is still cognitive decline
- Functions including working memory, executive functioning, episodic memory and processing speed decline as you age.
- But, vocabulary sees stability during young age, and an increase into older adulthood > vocabulary size increases as you age
- May find it difficult to name the word (tip of the tongue phenomenon) but the vocabulary bank is much wider than in younger adults
- These cognitive changes are related to changes in the brain
- Top diagram shows decline in grey matter volume and bottom diagram shows decline in white matter volume > there is significant variability here in terms of individual differences, some people are actually 70 years old but in terms of their brain age + grey matter volume they seem in line with someone in their 20-30s
- This variability can seem challenging as it is difficult to work out the trends for decline in cognition BUT this variability presents opportunities > for example if we find out the differences + variability between older people with high brain age and low brain age then we can think of possible interventions using such characteristics > how can we positively influence the trajectory of ageing?
6
Q
How does ageing impact language?
A
- Most research indicates there is no decline in language due to ageing > this is not really true, it is an old view
- Recent research looking closely at language and ageing show that ageing does impact language function
- Language is special in a way that some aspects of language improve like vocabulary while other aspects show a clear decline with ageing > makes sense because if our brain is changing with ageing, then language which is a very important part of cognition is likely to change
- For example looking at grammar and how complex the grammar used in sentences are produced by ppts (e.g. active/passive voice) > evidence shows from around 70+ grammatical complexity declines
- Older adults use shorter + simpler sentences
- Language production is not only impacted by age but also language comprehension > listening, understanding + reading language is affected by ageing
- e.g, one study had a task of detecting mistakes when hearing certain phrases. So the task would have correct statements like (I pull, she pulls) and incorrect like (I pulls, she pull) > young adults are more accurate then older adults in spotting the mistakes + young adults are faster than old adults in responding
- The variability is also much larger in older adults than in younger adults > variability is important in ageing
7
Q
Individual differences across domains
A
- the variability of ppts in language comprehension > measured those same ppts in other cognitive domains like working memory + processing speed.
- Older adults who scored higher in comprehension accuracy also scored higher in working memory task + those scoring lower in comprehension scored lower in WM > there is a relationship between WM and language comprehension accuracy
- Also, those scoring high on processing speed also scored high on comprehension accuracy > comprehension is related to processing speed
- Decline in syntactic comprehension is related to decline in working memory and processing speed > relationship between different aspects of cognition, being impaired in one aspect means you will be impaired in another aspect of cognition
Results also showed it took longer to respond/spot made up words > this was especially worse for those with low processing speed
8
Q
Numerical age vs Biological age
A
- Biomarkers of cognitive function include working memory, processing speed and executive function > if we can reliably measure these functions in people, it is a marker of their “biological” age
- Numerical age = age shown on passport, Biological age = kind of like brain age + can be lower than actual age. E.g. having a lower biological age means you are more likely to perform better on cognitive tasks
- These markers are all related to each other because those trajectories of ageing all impact cognition + starting to get a greater understanding of how decline in cognition is related to other age related decline like decline in physiological functions
- When you combine all kinds of biomarkers in a person you get a biomarker of how someone is ageing + their biological age
9
Q
Relationship between cardiovascular function + cognitive ageing
A
- Cardiovascular is relating to heart and blood vessels > how fit/functional is your cardiovascular health (can check this using VO2 score on phone or smart watch)
- This case study is about cardiovascular fitness and word finding abilities (language)
- To find cardiovascular fitness we put the ppt on a treadmill/exercise bike and + measure their oxygen consumption while they are exercising which reliably shows how cardio vascularly fit they are + then look at cognitive function
- Looked at word finding abilities using a tip of the tongue experiment > tip of tongue states when you can’t grasp a word you are thinking of, young adults have this too but gets worse as you age + happens most frequently with words you don’t use often (e.g. show a picture of an actress which they would know, so someone famous from their younger age)
- In this exp, definitions were shown for example “what was Princess Diana’s maiden name” > they respond yes they know it, no they don’t or I know it but I cannot get to it (tip of the tongue state has been elicited) > we are measuring how often they have a tip of the tongue state in the experiment then relate to cardiovascular fitness
- Found that the most fit people had the lowest probability of having a tip of the tongue state whilst the most unfit people had the highest probability of having a tip of the tongue state
- Other differences were controlled for between the participants such as average age + education level
- Degree of age related decline in cognition is related to the degree of health they experience (cardiovascular function in this case)
10
Q
Using research to make intervention
Exercise
A
- Exercise > We know that people don’t exercise enough > young adults don’t exercise enough + activity levels decrease with age
- Sharpest decline in people aged from 75-85 > people are not doing the recommended 30 minutes of exercise a day which is impacting cardiovascular fitness which relates to cognitive functioning
- Exercise is important because it is accessible, effective + a safe way to improve and maintain physical and cognitive health
- Meta analysis of intervention studies: intervention group who exercise and control group who don’t + measure both groups in cognitive tasks
- Effect size shows the difference between the beginning of intervention vs end of intervention > there is a small improvement in all cases the second time you test people but this improvement in performance in cognitive task is much greater in the intervention group than the control group
- Exercise benefits physical health but also cognitive health > relationship between different domains + aspects of a person
11
Q
Using research to make intervention
Cognitive training/intervention
A
- Would train someone on a cognitive function like EF > train by e.g. doing a switching task like looking at image of veg and fruit + saying which are fruit + which is veg then switching task to deciding what is bigger than the other + repeating this for weeks
- Meta-analysis shows the influence of this intervention
- Doing this improves EF, fluid intelligence, episodic memory, WM + processing speed > so training EF improves EF but also improves other cognitive functioning > Variability can be used to improve ageing
12
Q
Lifestyle factors impacting cognition + brain health
A
- Factors impacting cognitive variability include sleep, diet, exercise and cognitive training
- These all impact aspects of cognition thus impacting cognitive function > Lifestyle factors modulate how you age
13
Q
What is theory of mind?
A
- An understanding that other people have their own beliefs, intentions and knowledge states + that these may be different from our own + may differ from what is considered to be ‘true’ in reality > could be inconsistent with our perception of true reality
Two ToM domains: - Cognitive: understanding that others have thoughts and intentions
- Affective: Understanding others’ feelings and emotional states > close to empathy in theory
14
Q
How do we measure ToM?
A
- First ever experiment looking at ToM was conducted on a chimpanzee > showed a video of a person trying to reach an object or a series of object which were out of reach + hard to get hold of
- Then some pictures of solutions were shown of how the person could get the object (some were appropriate + others weren’t) > in this, the most appropriate solution was the actor getting a box to step on to get the object
- The chimpanzee more often than not chose the most appropriate solution to the problem which showed presence of ToM
- The chimpanzee thought about the actor’s intention to reach the object then chose the most appropriate solution to reach it
15
Q
ToM in children
A
- First tests of ToM were on children using the ‘Object-displacement task’ > measures false belief (refers to holding in mind another person’s belief state that we know is false)
- Story of Sally + Anne task: Sally put the ball in the basket and walks away, Anne picks up the ball from the basket + puts it into the box. Where will Sally look when she comes back?
- Adopted by Baron-Cohen et Al (1985) who studied typically-developing children, children w/ ASD + children with Downs syndrome > TD children passed ToM test aged 4-6 whilst children w/ ASD struggled > those with Downs syndrome performed better than those w/ ASD + more comparable to TD performance
- Shows that obstruction to passing false belief task is not due to a general delay in cognitive development but specifically related to ASD
