Introduction to higher cognitive functions Flashcards
What are higher cognitive functions?
Complex mental processes
Skills set of the brain
Perception, attention, learning, memory, decision making, language skills and reasoning
Define cognition:
mental action or process of acquiring knowledge and understanding through thought, experience and the senses
What is the general principle of higher cognitive functions?
requires the ability to process necessary information through multiple sensor inputs:
- inputs = sensory information
- processor = brain
- outputs = executive functions/actions (outputs are the things you selectively response to as you’ve chosen to be aware of them)
integrated processing - how the brain processes inputs and what outputs it sends out
What does mindfulness do?
teaches you to recognise things that you aren’t necessarily aware of beforehand - taking a moment to become aware of other stimuli around you
What is the cocktail party effect?
how you can know what your friends are saying when you are out at a busy bar and you’ve had a drink and there are lots of different stimuli yet you still manage to zone out other stimuli so you can focus on the conversation
What is the stroop test?
stroop effect is the fact you can respond fast to words that are present in that colour compared to naming the colour of a word that isnt that word
Selective attention
Colours are not necessarily an automatic process like reading
What are the key functions of the frontal lobe?
“basic computer”
Executive functions, thinking, planning, organising, decision making, problem solving, emotions and behavioural control and personality
Contains Broca’s area
What are the key functions of the parietal lobe?
Perception, making sense of the world, arithmetic, spelling
What are the key functions of the occipital lobe?
vision
What are the key functions of the temporal lobe?
memory, understanding, language
contains Wernicke’s area
What are the two areas involved in language?
Broca’s area: speech production
Wernicke’s area: speech comprehension
What are specific language disorders?
Spoken word comprehension (understanding speech)- receptive language disorder
Written word comprehension (reading) - language processing disorder
Spoken word production (talking) and written word production (writing) - expressive language disorder
What are the effects of Broca’s aphasia?
non-fluent / expressive / productive / motor aphasia
Impaired production of speech Severely limited speech output May have anomia Mainly content word (lack of function words) Lack syntax Frustration with difficulties- often using gestures to express themselves Comprehension is relatively normal impaired repetition Reading aloud is impaired Writing- poorly formed letters
What are the typical lesions causing broca’s aphasia and what is the typical pathology?
Left posterior-inferior frontal cortex and underlying white matter
Stroke of upper division of left middle cerebral artery
What are the effects of Wernicke’s aphasia?
Fluent / sensory / receptive aphasia
Severely impaired comprehension of spoken and written language
Impairment to location of memories of words
Fluent, socially conventional speech - meaningless though
Patient’s appear undisturbed by their difficulties but it can be very difficult for families
Use made up but similar sounding words
Repetition impaired
Reading aloud impaired
Well formed letters when writing
What are the typical lesions causing Wernicke’s aphasia and what is the typical pathology?
Superior posterior temporal region including angular gyri - commonly subcortical lesion of temporal isthmus
Stroke of lower division of left middle cerebral artery
What are the observations are you trying to attain in terms of speech and language in psychiatry?
Speech
- slowed
- fast
- disorganised
Language is expression of thoughts
- content (e.g. depressed, grandiose, paranoid)
- speed (e.g. poverty, mania)
- form of thought (schizophrenia, disorganised thinking)
What is language an expression of?
it is an expression of what we are thinking therefore it can be an important indicator for a psychiatric problem
- people who are depressed tend to demonstrate changes in their language
What brain functions are associated with the frontal lobe?
- voluntary movement
- language production
- comportment
- executive functions
- motivation
What brain functions are associated with the temporal lobe?
- Audition
- Language comprehension
- Memory
- Emotion
What does it mean by language dominance?
Left hemisphere is dominant for language in >90% of right handed people and 70% in left handed people
How can left hemisphere dominance be demonstrated?
Through:
- aphasias
- wada test
- split brain patients
- neuroimaging studies
- brain stimulation studies
What was phineas gage like post head injury?
Motor control, perception and language were all still intact
His QoL had deteriotated
General impairments in control (disinhibited, impulsive, antisocial, profane) with changes in mood and personality
Dysexecutive syndrome / frontal lobe syndrome / pseudopsychopathy
What are the functions of the frontal lobe?
Cognition and memory
Ability to concentrate and attend, elaboration of thought “the gatekeeper” for judgement and inhibition, personality and emotional tracts
Motor cortex- voluntary motor activity
Premotor cortex - storage of motor patterns and voluntary activities
Language - motor speech
What effects can damage to the frontal lobe cause?
Impairment of recent memory, inattentiveness, inability to concentrate, behaviour difficulties, difficulty in learning new information
Lack of inhibition (inappropriate social and/or sexual behaviour)
Emotional lability “flat” affect
Contralateral plegia / paresis
Expressive/motor aphasia
What are the different types of attention?
Sustained attention
Selective attention - voluntary and reflexive (automatic)
Divided -resource allocation models
Switching attention
Some people are better than others at dividing their attention
What is the central executive?
Integrating short term memory with our basic computer
- working / short term memory
- Acts like a coordination system for the brain’s attentional resources: - pholongical loop, visuospatial sketchpad, episodic buffer
Coordination of information from the frontal lobes
What does it mean by episodic buffer?
can’t have too much in there at any one time otherwise things start dropping off
What are the roles of the central executive?
Planning or decision making
Troubleshooting when the automatic processes run into difficulties
Novel situations (no prelearned response)
Dangerous or technically challenging situations - can override fears such as public speaking
Situations where there is a strong habitual response which needs to be overcome
What are ways of testing frontal lobe function?
Wisconsin card sorting test
Tests set-shifting, abstract reasoning and problem solving
What are the questions in the cognitive failures questionnare?
1) do you read something and find you havent been thinking about it and must read it again?
2) do you forget whether youve turned off a light or fire or locked the door?
3) do you fail to hear someone speaking to you when you are doing something else?
4) do you fail to see what you want in a supermarket (although its there)?
5) do you find yourself wandering whether you’ve used a word correctly?
6) do you accidentally throw away the things you want and keep what you meant to throw away?
What is FAB?
frontal assessment battery
- assess similarities - e.g. in what way is a table like a chair
- verbal fluency
- motor series
- conflicting instructions (sensitivity to interference)
- go no go (inhibitory control)
- prehension behaviour (environmental autonomy)
What happens to cognitive estimates in people with frontal lobe deficits?
produce widely abnormal estimates
