cognitive reserve Flashcards
what is the cognitive reserve
a buffer or resilience to AD
features of the cog reserve
-concept or abstract idea
-stern 2002: not always an obvious relationship between brain damage and test performance
-stern 2009: people sustain different levels of damage before the effects are observed
(suggest a buffer against damage)
why does cog reserve potentially hide evidence of AD for some time
indivs use alternative methods to maintain function e.g compensatory approaches
what is the brain reserve
-larger brains and more neurons can sustain more damage
-they have greater potential to be resilient and function adequately for longer
what is the threshold model of brain reserve
satz 1993
-disorder/injury/ age related decline has to exceed brain reserve threshold to have visible effect
-only brain reserve can determine the observable outcome
-similar types of damage doesnt have the same effect
weakness of threshold model
-cannot account for other indiv diff and doesnt take compensatory processing into account
-very narrow approach
does cog reserve have a fixed threshold
no
can the levels of cog reserve be enhanced
yes
what makes people more resilient to damage
-indivs who have flexibility in neuronal responses
-2 people may have the same amount of brain reserve but the person with more cog reserve is likely to tolerate greater damage
is cognitive reserve active or passive
active
-dependent on choices throughout development
-can be increased
-indiv differences and lifestyle factors can define age related brain change and resilience to pathology
is brain reserve active or passive
passive
-dependent on brain size and neuron count
-we cannot directly control
-indiv diff in brain structure defines age related brain change and resilience to pathology
could brain reserve and cog reserve be interlinked
yes
experience induced neuroplasticity research
kempermann et al 2002
-animal models suggest there is experienced based neurogenesis
-taught mice a new skill
-after 7 days, they had more neurons
-after 10 days, area of motor cortex increased in size
-over time a new skill leads to tangible changes in the brain
may 2011: support for this research bc cog stimulating activity can compensate for damage
experience induced neuroplasticity human research
draganski et al 2004
-juggling intervention
-daily training for 3 months
-structural change: increased grey matter at junction between temporal and occipital lobe
-humans can also influence their neuroplasticity
what does the neural reserve suggest
-there is not such a division between brain and cognitive reserve as first thought
-differences in cog reserve must have a physiological basis
what is the neural reserve
extent of our ability to allocate neural resources and form new processing strategies to keep functioning in the face of damage
what factors influence cog reserve
modifiable health factors e.g diet and exercise
education
social support
positive affect
stimulating activities
cognitive training
knowing second lang
which factor has the greatest influence on cog reserve
education
-higher education = greater CR
-cog in later life best predicted by educational attainment
what other factors is education related to
-markers of brain reserve (larger brains, thicker cortex - Lui et al 2012)
-quality of education more important than years of schooling
how does knowing a second lang influence CR
-life long bilingualism leads to more efficient and strengthened connections of neural resources
-can reduce cog decline in AD
what are the other contributing factors of bilingualism and CR
age of onset of second lang
proficiency and frequency of lang use
exercise and CR
-improves vascular physiology
-can form barrier to cog decline in the face of damage (Barnes 2015)
-increases cerebral blood flow and cerebrovascular reserve to promote greater neurogenesis
social activity and CR
-modifies relationship between AD pathology and cog
-less impact of pathology in those with larger social networks (Crowe et al 2003)
-past and present activities count
CR and AD
-differences in CR can account for findings related to AD
-mismatch between pathology and test scores
-indivs may have high load in relation to AD brain pathology (plaques and tangles) but not demonstrate deficits in neuropsych tests
-levels of CR prevents symptoms from emerging until the late stages
the nun study
Iacono et al 2009
-assessed nuns level of literacy (idea density) by autobiographies written by nuns aged 22 when entering convent
-higher literacy meant lack of cog deficits in AD pathology
-evidence that neurons can be influenced by life experiences
CR and AD diagnosis
-indivs with greatest cog reserve will have more advanced pathology at the onset of observable cog decline (at diagnosis)
-these indivs have less time until they reach the point when pathology overwhelms function and they have rapid rate of decline
-CR helps to attenuate experience of AD but this can be a hinderance bc an indiv will not make use of early stage interventions
education and diagnosing AD
-indivs with high educational attainment can be misdiagnosed with AD bc of their CR
CR and help seeking
Qian et al 2014
-indivs with high SES come to memory clinics at earlier stages of AD
limitations of CR
-more details needed on physiological processes that support CR
-need more longitudinal research
-the label of CR may not be useful, may be better to simply refer to lifestyle factors
future directions
-implement strategies to maximise CR in those most at risk
-increase education of CR and lifestyle factors across lifespan
-develop person centred training protocols for specific needs e.g exercise vs education
-cog screening of people with low education or poor reading could help detect early cog change/dementia
