Tutorials Flashcards
What is executive functioning?
- self-regulatory functions that organise, direct, and manage other cognitive abilities, emotional responses and behaviour
- allow us to plan and carry out goals, adapt to novel situations, consider consequences
What are the aspects of executive functioning?
Inhibition
Planning and organising
Cognitive flexibility
Concept formation, reasoning, problem solving
Are impairments of executive function specific to the frontal lobe?
No - but most patients who have damage to the frontal lobes experience impairments in executive functioning.
How would we divide the various components of executive function in the frontal lobe?
Dorsolateral PFC –> cognitive aspects
Orbitofrontal PFC –> behavioural aspects
Ventromedial PFC –> emotional aspects
What is the dorsolateral PFC associated with?
Cognitive parts of executive functioning: problem solving, organisation, cognitive flexibility, emotional range
What is the orbitofrontal cortex associated with?
Behavioural aspects of executive functioning:
- disinhibition
- impulsivity
- distractibility
- emotional lability (rapid changes in emotional states)
What is the ventromedial PFC associated with?
Emotional aspects
- apathy (disinterest)
- emotional blunting (reduced reactivity)
- impaired decision making
Why are there problems associated with neuropsychological assessment of executive functioning?
May not elicit impairments in executive functioning:
- the structure of the assessment leaves little room for inappropriate behaviour
- instead focus on qualitative assessment findings and informant reports
Tests also involve non-executive skills
Concerns regarding ecological validity (as you are in a 1 on 1 structured environment and are helping to regulate them)
What is the assessment of inhibition:
Inhibition = ability to withold automatic responding and instead respond in a novel (or less automatic) manner
Tests of inhibition:
- stroop test
- sentence completion test (complete the sentence in an unnatural way)
Assessment of planning and organisation:
Planning and organisation = identification of steps and elements needed to achieve a goal (conceptualizing changes from present circumstances, dealing objectively with oneself in relation to the environment, conceiving alternatives, making decisions).
Tests of planning and organisation:
- clock drawing
- rey complex figure test
- key search test
Assessment of cognitive flexibility:
ability to switch between different ways of responding - respond to changing situational demands
Tests of cognitive flexibility
- trail making tests (1A2B3C, etc)
- clock drawing (perseverative behaviours)
- sorting task (into different categories)
Assessment of concept formation, reasoning and problem solving:
= developing novel concepts and strategies to solve complex problems (evaluating performance, consider alternate solutions)
Assessment of concept formation, reasoning and problem solving:
- sorting task
- spatial anticipation task (predicting where the blue circle will move to)
- verbal fluency (FAS animal) –> semantic is usually easier, letter fluency involves more planning)
- reasoning based on verbal information (how are 2 words conceptually alike)
- reasoning based on non-verbal information (pick a tile that matches the pattern)
- tower task
What conditions affect executive functioning?
- TBI
- Frontotemporal Dementia
- Schizophrenia
Outline how TBI affects executive functioning:
- frontal lobes are particularly vulnerable to TBI due to their location and size
- nature and severity of impairments depends on the exact location and severity of brain injury
- e.g. Phineas Gage
Outline how frontotemporal dementia affects executive functioning:
This dementia is characterised by early and progressive changes in personality, behaviour and executive functioning.
Symptoms:
- disinhibition
- impulsivity
- mental rigidity
- perseveration
- poor insight
- loss of empathy
- apathy
Outline how schizophrenia impacts executive functioning:
- poor cognitive flexibility
- impaired planning and organisation
- poor insight
What is visual attention?
- supports conscious perception
- capacity limited
- selective in nature
- involves fronto-parietal networks
Visual attention occurs in 2 methods:
Bottom up processing:
- processing directly informed by environmental stimuli and salience
- involuntary
- temporo-parietal junction, ventral frontal cortex (orange)
- ventral attention network
Top down processing
- processing influenced by sensory input as well as experience and expectations
- voluntary (goal directed)
- inferior and superior parietal sulcus, frontal eye fields
- dorsal attention network
These interact
Visual processing and blindness
Vision processing is hierarchical and contralaterally)
- damage to earliest visual brain area cause blindness
- damage to brain areas further along the pathway do not cause blindness, but cause an inability to process specific features of a stimulus
- damage even further along can cause specific object recognition deficits (agnosias) but intact processing of basic visual features
What is the difference between the ventral and dorsal pathway
Ventral (bottom) = the ‘what’ pathway (object representation)
Dorsal (top) = the ‘where’ pathway (spatial representation)
What is the brief visual processing order:
Local features (edges, lines) –> shape representation (shapes, surfaces) –> object representation (e.g. a cows face)
What is an agnosia?
Inability to process sensory information.
Affects a signal sensory modality.
e.g. loss of ability to recognise objects, persons, sounds, shapes, smells, while the specific sense is not defect nor is there memory loss
What are some types of visual agnosia:
Categories
- apperceptive visual agnosia
- associative visual agnosia
Subtypes of visual agnosia
- simultanagonisa (inability to process multiple stimuli at a time)
- prosopagnosia (face blindness)
- achromatopsia (inability to register colour)
- topographical agnosia (inability to orient oneself)
What is apperceptive visual agnosia?
Difficulty assembling pieces / features together into common objects
- failure in earlier stage (perception)
- not very common
Have basic elementary features of vision (they can see it and attend to it, and semantic knowledge is intact) but they are unable to recognise or match objects.
impairments: object naming, object matching, object copying, shape identification, orientation judgment
i.e. impairment of shape representation
What pathology is apperceptive visual agnosia associated with?
- diffuse posterior damage
- recovery from cortical blindness (damage to the occipital lobe)
What is associative visual agnosia:
Can perceive an object but has difficulty naming it because they can’t link the visual percept to an identity (recognition without meaning)
- able to object match but can’t tell you what it is
- they are able to process the information / object through other modalities (therefore not anomia)
Can be material specific (e.g. letters = pure alexia), faces (prosopagnosia), navigation (topographical agnosia)
What is the underlying pathology of associative visual agnosia
Due to a defect in later stages of visual processing involving object representation (can describe the shape, but can’t recognise it)
Bilateral damage to the inferior temporal occipital junction
Outline the visual agnosia subtype: simultanagnosia
- difficulty processing visual input as a whole
- Dorsal: able to recognise elements but not the whole scene (bump into things in a room)
- ventral: multiple objects can be seen, manipulated, counted but can’t grasp the meaning of the whole scene (can’t put together the cookie story)
Prosopagnosia:
difficulty recognising faces
- known as face blindness
May recognise people based on extra facial features, gait, voice, etc
Acquired prosopagnosia (inferior medial temporo-occipital damage –> fusiform face area) due to TBI or stroke)
Congenital prosopagnosia (no neurological conditoin or intellectual impairment but may have a genetic component –> 2-3% prevalence rate)
Outline hemispatial neglect
- failure to attend / respond / orient to a stimulus or side opposite the lesion (not due to a sensory or motor deficit)
- may extend to all sensory modalities
- patient is often unaware of the deficit
Pathology: posterior parietal lesion of the right hemisphere
- right frontal lesions and lesions of the cingulate gyrus, thalamus, basal gnaglia
Transient (lasts no more than a few weeks)
What occurs during the acute stages of hemispatial neglect
- patients systematically orient towards stimuli on the extreme part of the non-neglected side
- marked deviation of head, eyes, trunk away from contralesional field
- compulsive orientation
- scanning saccades restricted to the ipsi-lesional side even if patient has full ocular movement to command
What happens during the later stages of hemispatial neglect
Extinction to double simultaneous stimulation
- patient asked to fix gaze: then test visual fields
- when two objects are presented at the same time, one in each visual field, only one will be reported
Line by section test
clock test
How to differentiate between hemispatial neglect and visual field sensory loss
Hemispatial neglect:
- not aware of deficit
- do not compensate for deficit
- attentional rather than sensory
Visual field sensory loss
- aware of deficit
- compensate for deficit
Constructional apraxia
an impairment in combinatory or organising activity so that desired synthesis cannot be achieved
seen on tests where individual elements must be arranged in a given spatial relationship to form a unitary structure
- inability to perceive how 2 or more parts form a whole
Test: copying, clock drawing, block design
How is memory organised?
Human memory:
Sensory (<1 sec)
Working memory (<1 min) - our ability to hold information and manipulate that information for a goal.
Long-term memory = encoded and stored
- Explicit memory: information we can restate (declarative memory [facts], episodic memory [experiences] and semantic memory [facts, concepts])
- Implicit memory (procedural memory [skills, tasks])
What is the process of remembering?
- attention
- encoding
- storage
- retrieval
Outline verbal memory:
Structured; short stories and comprehension
Unstructured; word lists (if they aren’t getting better in each trial, they are bad at encoding)
Outline visual memory
Draw the Rey figure - in 3 and 20 minutes ask them to recall as much of it as they can.
What is a temporal lobectomy?
- epilepsy = enduring brain disorder causing recurrent and unprovoked seizures
- the most common type of focal onset epilepsy is temporal lobe epilepsy –> most common cause being scarring in the temporal lobe (hippocampal sclerosis)
- hippocampal sclerosis causes isolated memory problems (storage issues)
What does memory look like after temporal lobectomy:
- unable to form new memories
- could retain information from moment (by repeating it constantly)
- could retain procedural memory (which relies on basal ganglia and cerebellum)
- declarative memory was most impacted
Outline how memory is impacted in Alzheimer’s disease:
- causes hippocampal atrophy
- primary memory impairment with later deterioration of other cognitive domains and functional decline
- characterised by rapid forgetting (difficulty with word finding, temporally graded retrograde and anterograde amnesia)
- storage and encoding is poor (recognition questions were performed poorly)
Outline Wernicke Korsakoff syndrome:
- due to malnutrition (thiamine deficiency)
- associated with heavy and chronic consumption of alcohol (metabolism of alcohol is reliant on thiamine)
- leads to lesions in mammillary bodies (encoding), thalamus, hypothalamus - and further lesions in frontal lobes, hippocampus, cerebellum
What does memory look like after Wernicke-Korsakoff syndrome?
- severe anterograde amnesia with confabulation (creating false memories)
- temporally graded retrograde amnesia
- recognition memory intact
What does memory in herpes simplex encephalitis look like
Case study: the conductor :(
Herpes simplex is a viral infection leading to encephalitis (brain inflammation)
lesions:
- lateral and medial temporal cortex (hippocampus = memory)
- orbito-frontal cortex
- cingulate gyrus
- parietal lobe
Results:
- acute confusional states followed by permanent, irreversible memory disorder
- severe anterograde amnesia (inability to form new memories)
- possible semantic deficits
- intact implicit memory (procedural)
- intact working memory (1 min)
What are the similarities:
- impacted anterograde amnesia (hippocampus) therefore unable to learn new things
- most impacted declarative memory
- unable to properly store memory
- procedural was kept intact
Recommendations for memory:
For people with issues with retrieval:
Cues to prompt recognition:
- external strategies
Mental strategies - internal strategies:
- mnemonics
- alliterations for names
- active rehearsal (if they are poor at coding)
- associations w tunes
- chunking
- memory palace
What is the process of information gathering?
- medical history: hearing or vision concerns?
- birth and developmental history
- educational history
- background history
- family history: maternal and paternal
- psychosocial context
- current concerns: parent, teacher
- current performance (social functioning, academic performance)
- previous assessments?
- observations of child and family
Areas to look at!
- presentation
- intellect (verbal and nonverbal, working memory and processing speed)
- learning and memory
- attention (flexibility, sustained, divided)
- academic functioning
- executive functioning
When doing test selection, you must consider:
- referral question
- area of concern (and strengths)
- putting concerns into context
- child’s age
- potential ability level and likely impairments
- availability of normative data
- disabilities
- prior assessment (if they have done assessment more than 12 months ago, use the same / similar batteries to compare - and be aware of practice affects)
What are some tests for different domains?
- IQ: WISC (verbal and nonverbal intellect, working memory, processing speed)
- Diagnostic literacy (single word reading) = CC2 (Castle’s and Coltheart Test)
- Academic functioning: WIAT
- ADHD screening battery for children: Connor’s 3 Questionnaire
Recommendations
- psychoeducation and behavioural intervention
- clinical psychologist (behavioural management)
- review recommended
