Intelligence and ageing Flashcards
What are some methodological issues related to the studying of ageing?
-factorial stabilty: initially it was thought that there may be an issue with studying younger pops vs. older pops - found that the structure of cognitive abilities remains differentiated throughout the lifespan. This means that we can safely use the same test with both groups of subjects.
The two basic designs employed in life-span developmental research are
cross-sectional and longitudinal. Evaluate these methods in terms of the
quality of information they provide about the role of ageing in cognitive
decline.
Both provide very important information towards the role of ageing in cognitive decline.
Cross-sectional:
- allows us to study people who at the time of testing, vary with respect to age –> using these studies, chronological age is usually treated as a variable and one can obtain the correlation between age and performance on different psychological tests.
- however, there are big issues with cohort or generational effects such that there are differences in populatios according to the time in which they are being studied rather than actual differences between the two different aged populations (i.e. namely, different emphasis on different aspects of education at different times)
- this can cause major issues in terms of the conclusions that we can draw from this sort of research.
Longitudinal studies:
- have long been thought of as the ‘gold-standard of ageing research, as they allow researchers to follow the same set of people every several years and they have to do the same tests or parallel forms repeatedly. By observing changes in arithmetic means over time, one can conclude whether the ability of interest changes over time.
- however, they also come with their own problems, namely, large attrition rates (people drop out after a long period of time) and also death-drop out rate which means that people are likely to die over this time and therefore become discounted from the study. Some argued that this could create bias towards results of studies because the results of ppl that have died are being excluded. Also suffer from cohort effects but perhaps not to the same effect.
Thus while some abilities showed a clear decline in cross-sectional designs, this decline was less pronounced and sometimes barely noticeable until 70 with longitudinal designs.
Therefore, we need to see the results from all studies to properly account for these different issues.
What is the difference between cross-sectional, cross-sequential and longitudinal designs?
- Cross sectional: looks at different ages at the same time period
- Cross- sequential: look at the same people at certain time intervals like longitudinal; at each testing time the sample is supplemented with a new group of ppl of different ages, similar to cross-sectional (complicated by cohort effects e.g. cross-sequential)
- longitudinal: examines the same people over several years using the same or parallel forms of tests. By observing means over time, one can make conclusions about the variable of interest over time.
What is the general trend of cognitive abilities with regards to age?
- Gf tends to decline past the mid twenties: this is usually related to a decline in physiological processes of the Central Nervous system
- Gc tends to remain the same or even increase with age (Gc depends on education and acculturation which continue to increase throughout the lifespan with more experience)
- this means that processes of Gc can offset the deterioration in Gf so that the overall performance level on IQ tests remains stable throughout the lifespan
- however, Gc tends to decline around 60-65 so that the compensatory effects cannot be overcome overall anymore.
What are the findings with regards to perceptual and visual perceptual abilities?
- decline past the young adulthood stage
- processes that are due to long term memory, however, seem to follow trends similar to those of Gc.
- therefore, a general picture of the ageinig process appears rather depressing.
What was an initial thought as to why there has been a pronounced decline in ageing?
- it was initially hypothesised that there was a marked reduction in perceptual and sensory processing with age.
- another theory was that it may be related to risk aversion (i.e. they don’t guess- found not to be the cause)
What are two competitors for the basic processes that are responsible for the decline in fluid intelligence with age?
- Speed of neural processing: i.e. younger ppl do tests faster; elderly are much slower han young in doing complex tasks than in doing simple tasks.
- cognitive capacity.
What is the consensus regarding age-related decline in Gf related to a reduction in cognitive processing?
- there is little disagreement –> old ppl are slower than young ppl in their reaction to any kind og external stimuli
- the r/s between age and speed of mental operations increases with the complexity of the task - such that as complexity increases, the difference between old and young increases.
- more recent debates have said that speed of processing and WM are independent contributors and therefore WM deficits are accounts for in terms of something other than speed.
How is long term memory affected with age?
- only particular processes show decline –> elderly perform as well as young on tasks requiring recognition, but worse at reproduction.
What are the two type of capacity systems?
- working memory
- attentional resources
How is it believed that WM is affected during ageing?
- two parts (ACTIVE AND PASSIVE)
- we know that passive part is not affected (through digit span tests)
- however, it’s hard to test tasks that only use the active part
- but we know that overall WM decreases with age so we must put it down to the active part because the passive part isn’t affected.
- thus, it is concluded that older ppl are not as able as younger ppl to carry transformations and manipulations in their immediate awareness.
What does attentional resources refer to and what are the findings regarding attentional resources with regards to ageing?
- firstly, this refers to the amount of processing resources than an individual has at his/her disposal for the solution of a cognition problem
- FINDINGS: there is a reduction in tasks with high attentional demands, but those with little attentional demands are largely intact.
What are the general findings related to general health in the ageing population?
- that cognitive function it is not strongly related to general health
- this is different, however, with some specific diseases that affect brain functions
How does cardiovascular health affect changes in cognition?
- poor circulation can lead to a reduction in adequate blood supply and nutrients to the brain cells
- there is convincing empirical evidence that demonstrates that a prolonged untreated cardiovascular disease is related to a gradual loss of brain cells
- therefore, blood pressure is an important issue to consider when examining cognitive ageing (it has a significant detrimental effect on intelligence even after on controls for age, education and gender)
How does Diabetes assume to be related to cognitive changes in ageing?
- both physical and psychological changes in DM resemble changes seen in ageing and thus it is said that it may be an accelerated ageing process.
- particularly damaging to cognitive function appears to be the repeated occurrence of hypoglycaemia
