Cognition Flashcards
What is sensation?
sensory and neural encoding of incoming physical information
What is perception?
interpretation of sensory information
How is cognition related to sensation and perception?
sensation constructs perception, and cognition integrates different perceptions to make meaning
Conversely, higher cognition - our thoughts - can also influence the way we sense
Why is it useful to study cognition?
1) diagnosis, such that cognition breaks down in specific pattern if brain is damaged
2) understand the best approach in treating patients, thus improving patient outcome
How is cognition studied in animals and humans?
animals - lesion studies
humans - case studies
What is an example of lateralisation of brain function?
left hemi for language, right hemi for visuospatial function
Note that this is not absolute and does not take into account the individual differences
In Luria’s brain-behaviour theory, what are the basic units and what are their functions?
brainstem - regulation of arousal and muscle tone
posterior cortical zone - governing sensory information
anterior cortical zone - planning, executing and verifying behaviour
The cortical zones are separated into primary, secondary and tertiary zones, which zone is most topologically organised? Which one develops the latest?
primary zone
tertiary zone develops the latest
Why is cognition usually not one-to-one with the respective brain area?
cognition is a system, and damaging any part of the system can cause impairment
What is the adaptive significance of emotion?
we can recognise the emotion of others and respond with emotions of our own
Which system is involved in emotion? Which areas are within this system?
limbic system, consisting of cingulate gyrus, amygdala, hippocampus, hypothalamus
What is Kluver-Bucy syndrome? What kind of symptom does the animal experience?
bilateral anterior temporal lobe removal
symptoms include tameness or loss of fear due to amygdala dysfunction
What is the role of orbitofrontal cortex in emotion?
identification and expression of emotion (you can still feel it)
Is emotion lateralised?
Yes, lesion to right orbitofrontal cortex is worse than that of the left
The reduction of which three areas tend to be related to depression?
Amygdala, orbitofrontal cortex, hippocampus
What is the executive function of frontal lobe?
processes responsible for goal directed, purposeful, emotional, and social behaviour
the pre-frontal cortex is divided into which three sub-cortex?
dorsolateral cortex
medial prefrontal cortex
orbitofrontal PFC
List the functions of dorsolateral cortex
working memory response selection planning and organising hypothesis generation insight moral judgment
What is response selection?
the ability to change response (strategy) in order to solve a problem
What is insight? What is “insightless”?
the ability to recognise the problem
Cannot recognise the problem, think they are fine. Treatment is thus very difficult
what is the blood supply for dorsolateral cortex?
middle cerebral artery
What is working memory?
capacity to keep info in mind and use it
like remembering digits in reverse, which is taking in information and manipulate it
What is medial prefrontal cortex’s function?
associated with emotion and motivation
What will a MPFC lesion result in?
akinetic mutism, apathy, initiative, indifference
don’t talk, don’t initiate, general lack of engagement
note that the motor programs are intact, and this is not a mood issue or depression
Do MPFC share some functions with orbito PFC?
Yes, some emotional, motor and attention programs are also associated with OPFC
Which area is highly connected to orbito PFC?
the limbic area, associated with emotional process
What will a lesion in OPFC result in?
lack of inhibition on emotion, cognitive function and social responses. Tend to be very impulsive, cry and laugh inappropriately
What is cognitive disinhibition
defect associated with OPFC. It describes the failure to stop a task
T/F OPFC lesion causes the patient to make a lot of mistakes
True, patients tend to take a short time to make decisions and make a lot of mistakes
What is the blood supply for MPFC?
supplied by anterior cerebral artery
what is the blood supply for OPFC?
anterior cerebral artery and middle cerebral artery
The frontal lobe is ______ in terms of maturation and also degenerates the _______
slowest
fastest
Why are teenagers more likely to engage in risky behaviours
because frontal cortex is not fully developed, there unable to make the right decision
Why is “executive dysfunction” a better term than “frontal dysfunction”
you can damage other places in the brain to get cognitive dysfunction. Frontal implies that the lesion is specially in the frontal lobe
what are some positive symptoms of executive dysfunction
distractibility social disinhibition emotional instability perservation impulsivity hypergraphia
what is perservation
unable to stop doing a task and move on
keep doing the task even if it is done (you just repeat)
what are some negative symptoms of executive dysfunction
lack of concern restricted emotion deficient empathy failure to complete task (not the same as "finish" task) lack of initiation
What does the tower of London test for?
ability to plan
What does the stroop test test for?
ability to inhibit a response
What does the Rey complex figure test test for?
ability to plan
What is aphasia?
disorders of language as a result of brain damage
What are some causes of acute aphasia?
stroke
penetrating head injury
surgical resection
What kind of aphasia can a migraine patients have?
paroxysmal episodic
Which hemisphere is important in language for the majority of people
left
What is the role of right hemisphere for language in people who are left brain dominant
It plays a role in understanding language: the tone, interpretation, and the social aspect of language
What are the two components of language system?
language production - construct sentences that make grammatical sense
language selection - choosing appropriate content
What is fluent aphasia?
Due to a Wernicke’s lesion, there is impaired selection of content. Sentences have proper grammar, but the content makes no sense
What is non-fluent aphasia
Due to a Broca’s lesion, there is loss of grammatical structure in the sentences, but there is intact selection of content
What is arcuate fasciculus?
a hypothetical tract that links Wenicke’s to motor/premotor and Broca’s area
One of the syndromes of Wenicke’s aphasia is fluent jargonistic language output, what are the two types?
Neologism - consistently use a made up word
Paraphasic error - use boap instead of boat, elevator instead of escalator
What are the other syndromes of Wenicke’s aphasia?
fluent jargonistic language output
impaired comprehension
right quadrantanosia, because lesion is often associated with visual tract
What are the syndromes of Broca’s aphasia?
non-fluent, effortful language output
telegrammatic (brief sentences)
preserved comprehension (thus very distressing)
right face and arm weakness (very close to motor cortex)
key words are preserved
What is conduction aphasia caused by?
lesion in the arcuate fasciculus
What are the two mechanisms of aphasia recovery?
contralateral transfer (occurs more in children)
ipsilateral re-organisation (reorganise function to surrounding area)
Which mechanism leads to best aphasia recovery?
bilateral reorganisation - a combination of contralateral transfer and ipsilateral re-organisation
T/F bilateral temporal lobe resection is common
False, although unitemporal resection is common
T/F retrograde amnesia can recover overtime
True, patients can shorten the retrograde amnesia state overtime
T/F Procedural memory and working memory will be lost if we remove the inferior temporal lobe
False, patients generally lose only the ability of forming new long memory
What is non-declarative memory?
unconscious memory like skills and habits
What is declarative memory? What are the two types of declarative memory?
memory that we can consciously recall as knowledge
episodic - events in time related to you as a person
semantic - non-contextual facts
What are the three major parts of the hippocampal system? What are their functions?
hippocampus - consolidation of memory
entorhinal cortex + perirhinal cortex - take up memory
How is memory lateralised in a left brain dominant individual?
verbal memory lateralised to the left
non-verbal memory lateralised to the right. Right side is more to do with visuo-spatial association and face recall
What is paired associate learning and what can it be used for
give unrelated words (table + grass) and ask patients to learn the unrelated association
it’s the best way to assess declarative memory.
what are the four possible categories of memory impairment
degenerative disorder
cerebrovascular disorder
transient disorder
surgical resection
What is the specific pathology of temporal lobe epilepsy
hippocampal sclerosis, tissue is atrophied, gliosis and hardening of hippocampus
What is the clinical presentation of temporal lobe epilepsy?
declarative memory disturbance
Lesions in which 5 other structures can cause amnesia?
mammillary bodies retrosplenial cortex mesial temporal region bilateral anterior thalamus lesion basal forebrain
What is the difference between H.M’s amnesia and transient global amnesia?
TGA has a very sudden on-set and there is no disruption of self-identity
T/F post-traumatic amnesia can spontaneously resolve
True, and the duration is an assessment of the severity
What is the most important risk factor of Alzheimer’s?
age
How do patients with mild cognitive impairment present?
self-reported short history
mild objective memory impairment
unaffected general cognitive function and ability to perform daily tasks
T/F asymptomatic Alzheimer’s patients will have plaques in the neocortical association cortex
False, they only have plaques in the transentorhinal region
What is the first cognitive test to diagnose someone who may have Alzheimer’s?
paired associated learning test
How do you differentiate mild cognitive impairment and anxiety disorder in an interview?
with MCI, you specifically do badly in episodic memory. With anxiety disorder, you tend to do badly across the board
How is cognitive rehab done in the modern days?
active participation model with main goal being recovering skills related to daily tasks.
It focuses on enhancing participation and reducing functional limitations
T/F cognitive impairment is often linked to anxiety and depression
True, post-stroke depression for example is very common
What are the two categories of cognitive interventions
environmental modification and compensatory strategies
What kind of environment tend to help brain recovery
dark, quiet environment
what are the two strategies of compensatory cognitive intervention
internal - improve one skill set so other skills can be used
external - use cues to aid deficit (diaries, apps)
