cognitive ageing Flashcards
cross sectional vs longitudinal studies with ageing
many decline with age in cross sectional studies → some stay constant or show improvement
less dramatic drop in longitudinal study
difficult to avoid the issues with this
crystalised vs fluid memory
semantic = crystalised
episodic = fluid
semantic - Verhaeghen (2003) - meta-analysis of vocab test studies
older adults outperform younger adults on vocab tests - especially MCQs - with large effect size
* due to more years of education
older people outperform on MCQs → might need clearer cues to aid semantic knowledge
Flynn effect → increasing scores with birth year
large sample spreading many years with many cohorts allowed him to see this
semantic - Nelson and Naren (1980) - study with general knowledge questions
general knowledge question asked - normed
older adults outperform younger on these → knowledge acquired over a lifetime
semantic - mayor et al (1994) - mastermind study
study of mastermind quiz show
correlations between accuracy of answers and age in both specialist subject and general knowledge
don’t see effects of age with specialist subject, general knowledge is positively correlated with age → already experienced and interacted with lots in that subject if it’s your specialism
semantic - laver and burke (1933) - meta-analysis of semantic priming
network models → spreading activation as words become associated with each other in very complex ways
with age, these become more connected → helps semantic memory
hearing one word activates others through this - semantic priming, remains intact in old age and can even improve with age
older are slower compared to younger in most tasks, but proportionally faster with priming
binder and desai (2011) - brain areas with semantic memory and age
diffuse network of brain regions underlie semantic memory - not same areas as episodic
these areas are shared with other sensory/perception and motor/action areas
less dependence on areas for episodic memory which decline in older age e.g. hippocampus
episodic memory - define recollection and familiarity
recollection = remember = specific contextual, associative, perceptual info
familiarity = i know = memory in the absence of retrieving specific details, feels familiar but can’t quite grasp it
episodic - remember/know test meta-analysis - McCabe et al
memorise a list of words, then present words from the list and ask if they remember (recollection) or know (familiar) it was on the list:
- remember specifically or just feel like they studied it but with no other details - can have false alarms too
results:
- decline in recollection (remember) with age
- equally good familiarity (know) based judgements with age
episodic - changes in brain structure with age - Raz et al (2005)
volume reductions (4)
stable/minimal reductions (2)
loss of structural integrity (2) and not (1)
cerebral cortex volume changes with age - longitudinal study
reduce in volume:
* caudate nucleus
* lateral prefrontal cortex
* cerebellar hemispheres
* hippocampus
stable/minimal reduction:
* primary visual cortex
* entorhinal cortex
hippocampus and caudate nucleus decline in structural integrity - entorhinal cortex remains same
double dissociation between recollection and familiarity in hippocampus and entorhinal cortex - study
double dissociation = two related mental processes are shown to function independently of each other
study = integrity of brain areas associated with recall and recognition in older adults
assumptions:
* recall (coming up with words independently) relies more on recollection than familiarity
* recognition (saying if word presented was on list or not) relies on familiarity more than recollection
results:
* performance on recall tests more strongly associated with structural integrity of hippocampus
* performance on recognition test related to volume in entorhinal cortex
demonstrates why older adults struggle with recollection compared to familiarity due to decrease in hippocampus size but stable entorhinal cortex
theories of aging and episodic memory (3)
dual process theory:
- become more deficient in recollection and less in familiarity with age
associative deficit hypothesis:
- become more deficient in memory for association and less in memory for individual items with age
source monitoring framework:
- become more deficient in memory for source and context and less in memory for specific content/items
interactions between memory systems with age study - Jarjat et al (2021) - method and 2 dimensions of source memory given
method:
- study word pairs which were sometimes related and sometimes not
- repeat one of the words from each pair immediately after studying them
- make a decision whether presented pair was related or not
recognition test:
shown a word and asked
- was it presented or not?
- which side of the screen was it shown on?
- was it from a related or unrelated pair?
gives 2 dimensions of source memory → original location (non-semantic arbitrary) and original relatedness (semantic, meaningful)
interactions between memory systems study - Jarjat et al (2021) - results
memory for meaningful source info preserved in older age
interactions between memory systems study - Jarjat et al (2021) - three dimensions of source memory
joint source memory = likelihood that you remember both sources of location and relatedness
semantic source memory = likelihood that you remember the relatedness source (related or unrelated pair)
non-semantic source memory = likelihood that you remember the location (left or right of screen)
OA = worse non-semantic source memory than YA
OA = no deficits in semantic source memory
extensive knowledge in semantic memory (relatedness) acts as buffer against episodic deficits (location)
