L8-14 Flashcards
alzheimers symptoms
- loss of memory
- impaired reasoning
- reduced language skills
- loss of daily living skills
alzheimers test
Phonemic and Semantic Verbal Fluency (SVF)
- 1 min, how many words wither starting with a letter or belonging to a semantic category (e.g. animals)
alzheimers primary risk factor
AGE – after 65, risk of developing doubles every 5 years
alzheimers brain changes (4)
- brain atrophy, especially hippocampus and cortex
- plaques = clumps of beta amyloid
- neurofibrillary tangles = inside cells
- degeneration in basal forebrain
beta amyloid plaques
- anyloid precursor (APP) → role in synaptic plasticity
- B-amyloid when APP is cut up
- overproduces in AD, sticks together and clumps
- leads to degeneration of the cells
new AD drug relating to plaques
- Donanemab - antibdy medicine
- reduces beta amyloid and reduces cognitive decline
- doesn’t stop but slows down
neurofibrillary tangles
- tangled microtubules - the scaffolding in cells
- stabilised tau protein
- in AD, tau disintegrates and forms clumps
- location of tangles corresponds will with symptoms
degeneration in basal forebrain
- nuclei send projections into cortex, especially to release ACh
- degeneration = decreased cholinergic transmission
= decreased memory - mild-moderate AD can be treated with cholinesterase inhibitors (inhibit reuptake)
APOE gene variation - role in AD
- three major variations (alleles) of the APOE gene- called APOE2, APOE3, APOE4
- ApoE mainly produced by astrocytes, and transports cholesterol to neurons
- having ApoE4 allele, esp 2 of them, leads to increased AD risk
- has to do with maintaining pericytes at BBB
protective factors against AD
better education early on either prevents AD or encourages more intellectual activities throughout life
higher idea density scores in early life are associated with intact cognition in late life despite the presence of AD lesions.
n-back test
indicate when the current stimulus is the same as the one n back from it
- fMRI shows DL PFC active
- ability to repress irrelevant info (e.g. lures)
define inhibitory (self)-control
Where previously reinforced, highly reinforcing, or well learned (habitual) responses have to be suppressed
- important for group living
Hot/cold framework
hot = emotional, reflexive, accentuated by stress
cold = cognitive, complex, slow, reflective
utilisation behaviour
- behaviour driven by stimulus
- e.g. glasses on desk, hammer and nail
- when PFC damaged
Wisconsin Card Sorting Task with PFC damage
PFC damage = makes it really hard to change behaviour when criteria changes
role of dorso-lateral PFC in self control
DLPC has connectivity that allows it to in modulate action execution and
evaluation
Raven’s Progressive Matrices
- test for non-verbal reasoning
- finish the pattern etc
- activation in dorsolateral region
Frontal Lobe Syndrome - symptoms and why
- Cognitive impairments = deficits in temporal ordering, goal directed behaviour and abstract reasoning. Poor decision-making
- Emotional changes = apathy, anergia, socially inappropriate outbursts
- Behavioural deficits
= Utilization behaviour, perseveration, environmental dependency, socially inappropriate behaviour, risky behaviour
Balint syndrome
= can only perceive one object at a time
- e.g. spoon or pen
- associated with parietal lobe lesions
PFC damage + creativity
in most cases, PFC associated with decreased performance on task of creativity - originality, flexibility, fluency
- need divergent thinking, combining available knowledge
2 systems of decision making
system 1 = experiential-affective
- rapid, undemanding, associative, mostly automatic
system 2 = analytical
- rational, controlled, slow, conscious
parallels hot/cold model