Clinical Neuropsychology executive functioning Flashcards
What is the dorsomedial frontal lobes main function?
Located at the top (dorsal/fin) part of the frontal lobe, its main function is planning and problem solving. Most neuropsychological test of executive functioning target this area.
What is the function of the medial frontal lobe?
The medial frontal lobe is responsible for initiation and drive. It links intention and behaviour and is connected with the limbic system. It shares some common syndromes with the ventral fl. Can be confused for depression (akinetic mutism then abulia and apathy)
What is the role of the ventral/orbital lobe?
Main function is to regulate, inhibit and emotional processing. Closely connected with the limbic system
What does damage to the ventral lobe present as?
Difficulties with higher order decision making, reversal of previous stimulus response learning, impulsivity, irritability, poor judgement
What is the US definition of executive functions?
They are adaptive behaviour patterns most often required in novel situations and where established patterns are not successful.
LEZAK (2012) US definition
- Volition - intentional behaviour, determining a need and conceptualising some future realisation of this
- Planning - identifying and organising the steps and elements needed to achieve a goal
- Purposive action - translation of a plan to productive activity, initiate maintain switch and stop sequences of behaviour.
- Effective performance - monitor, regulate qualitative aspects e.g. Intensity
What is the UK definition of executive functioning?
BURGESS & ALDERMAN (2004) defines executive functioning as the abilities that enable a person to:
- Determine goals
- Formulate new and useful ways of achieving them
- Adapt their proposed course in the face of competing demands or changing circumstances
Some common reported symptoms of dysexecutive syndrome are:
BURGESS (2003) lists 20 common symptoms of executive dysfunction. Some of which are:
Impulsivity Confabulation Disinhibition Perseveration Know-do dissociation
What is dysexecutive syndrome?
Term originally coined by BADDELEY (1986) to refer to the constellation of behaviour and cognitive deficits seen in patients with FL damage.
Following introduction of imaging techniques, the definition has been amended to remove the focus on the localisation of the FL and consider the connections and areas (posterior and sub cortical)
Why might reference to DES as a syndrome be inappropriate?
Since a syndrome suggests a fixed set of symptoms. In DES only a few of the symptoms may be present but clinically significant.
What are the impacts of DES in daily life?
Headway (2011) -
Often lack insight into difficulties making it hard to explain difficulties and behaviours
Misunderstood as depression, aggression, selfish which can impact on relationships
Emotional impact - frustration, embarrassment, isolation
Work - hard due to problems with multi tasking, organisation and motivation.
Who wrote about the supervisory attention system?
Shallice and Burgess (1996)
Who the theorised about goal selection and neglect ‘G’?
Duncan et al., 1996
Somatic marker hypothesis
Damasio et al 1996
Clinical model of executive functioning
Mateer (1999)
What is the SAS?
A decision making model of executive functioning. Contention scheduling initiates appropriate scheme under well learned routine situations.
In situations involving: Decision making or planning Error correction or trouble shooting Novel Well learned responses are ineffective Dangerous or difficult Overcoming strong habitual responses or resisting temptation ... The SAS steps up as a supervisor
Oversees contention scheduling by influencing schema activation and allowing general strategies to be applied to novel processes
What is stage one of SAS model
Construction of temporary new schema. Can take three routes.
Problem orientation (Des can fail here, fail to notice a problem)
Goal setting
Aspiration setting
- Spontaneous schema generation - try random
- Progressive deopening phase - continue to try and evaluate in stage 2
- Episodic memory retrieval - more delayed, consider previous experiences that have worked before
What is stage 2 of the SAS?
Implement new strategies and form temporary new schema
What is stage 3 of the SAS?
Temporary new schema are monitored and assessed. May be rejected or stored as a future strategy
What does the SAS hypothesise about those with fl damage?
dorsolateral - more likely to rely on CS, hard to problem solve and generate new ideas
Medial - take easiest option, lacks drive unable to set goals or aspirations
Ventral - continue to try same schema that haven’t worked, unable to learn stimulus response, may use a spontaneous strategy
What does the SAS model suggest assessment should cover as a minimum?
- General measure in inhibitory ability e.g verbal fluency, TMT
- Executive memory abilities in St and lt (WCST, Brixton, story and figure recall, word list recall, observation of real life event recollections)
- Multi tasking (6 elements BADs, multiple errands)
What is Duncan’s theory of g?
The PFC main function is control of action for desired results. Forming selecting and monitoring goals.
More recently proposed PFC main function is to support ‘g’ (fluid intelligence) used in the control of diverse behaviours
Goal neglect is a failure to translate intention into action. Mostly occurs in novel and unstructured settings. Sensitive to prompts and verbal mediation (goal management training)
What are the processes of goal selection and task performance (Duncan’s theory of g, 2000)
- Generate a goal list
- Goal list guides action structure
- Continuous process of means-end analysis
- Discrepancy analysis
- New goals list and action structures
What is the somatic marker hypothesis (Damasio et al., 1996)
Understanding human reasoning and decision making, ventro-medial PFC. The role of the FL in emotion and social behaviour
Close links with cortical and sub cortical (amygdala and hypothalamus) so considers overt and covert operations
Somatic markers describe the bioregulatory feedback processes - bodily response to emotions
Somatic markers guide the user, with S-R links engrained in somatic markers
Come from Iowa gambling task (Bechara 1994)
Parallels with the SAS
What are the implications of FL damage according to the somatic marker hypothesis?
Ventromedial PFC damage means people are unable to mark or link inappropriate behaviours with an emotion related somatic signal.
They may understand the implications but not be able to practice this.
Thus show difficulty regulating behaviour as they can’t make use of somatic markers - do not get the biases so keep making same mistakes.
What are the assumptions of the somatic marker hypothesis?
- VMPFC is a store of recorded linkages between factual knowledge and bioregulatory states
- Re activation of these factual-emotional links leads to factual knowledge of the situation and the option for future actions to be represented somatically in the brain
- Marker then serves either at covert or overt level
- Markers participate in the content of experiences or actions as well as influencing the process
- They provide emotional feedback for certain Contingencies (links). This means that logical reasoning is facilitated so the individual only has to to a logical analysis when no somatic marker is available. (Slow relies on previous experience)
According to Mateer’s (1999) clinical model of executive function which anatomical location is associated with initiation and drive
Medial frontal lobe
According to Mateer’s (1999) clinical model of executive function which anatomical location is associated with response inhibition (perseveration)
Orbitofrontal or ventral
According to Mateer’s (1999) clinical model of executive function which anatomical location is associated with Task persistence?
Medial FL
Orbito/ventral FL
According to Mateer’s (1999) clinical model of executive function which anatomical location is associated with organisation (action and thoughts)
dorsolateral fl
According to Mateer’s (1999) clinical model of executive function which anatomical location is associated with generative thinking
Medial FL
According to Mateer’s (1999) clinical model of executive function which anatomical location is associated with awareness - monitoring and modifying behaviour
Not well specified all of PFC
Desribe Stuss & Levine’s (2002) fractionation of the PFC
Used clinically more than the three factor model
- dorsolateral PFC
- ventral PFC
What are the difficulties associated with dorsolateral PFC damage
Language deficits
Memory
Attention
Concept formation and set shifting
Describe language difficulties associated with DLPFC damage
Left sided - simplification and repetition of sentence forms and omissions of elements
Right sided - amplification of details, wandering from the topic and insertion of irrelevant elements -> loss of narrative coherence
How would you assess language deficits in DLPFC damage
Verbal fluency
Category fluency
For activation and formulation deficits
Describe memory difficulties in DLPFC damage
Particularly right side,
The information is there but cannot access it,
Strategic processing, coordination and interpretation, retrieval, confabulation, re duplicative paramnesia (place duplicated) focal retrograde amnesia (isolated past events)
How would you test for memory difficulties associated with DLPFC damage?
WMS good for temporal and frontal memory
Describe the attentional difficulties associated with DLPFC damage
Difficulties can exist in:
Switching and alternating attention
Selective attention
Sustained attention
How would you measure attentional difficulties in DLPFC damage
Switching / alternating - TMT B
Selective attention - stroop - requires inhibition of attn to competing stimuli
Sustained attn: typically not well tested in axs
Letter cancellation (link to sustained attn unclear)
The sustained attention to response test (SART) Robertson 1997
Elevator counting test Robertson 1991
Describe concept formation and set shifting difficulties in DLPFC damage
Requires rule generation and identification, hypothesis testing, maintenance of attn utilisation of feedback and switching categories
What test would you use to assess concept formation and set shifting
Wisconsin cart sort
Brixton spacial anticipation
What areas of cognitive functioning is Ventral PFC associated?
Emotional processing Decision making Behavioural self regulation Episodic memory and self awareness Social cognition and TOM
Describe behaviour self-regulation difficulties associated with VPFC damage
Inhibit inappropriate behavioural responses in favour of better lt outcomes, particularly in unstructured situations
Inability to hold a mental representation of self on-line and use this information to inhibit response
Describe decision making difficulties associated with VPFC damage and how you would test for them
Impaired decision making as a result of impaired emotional biasing - somatic marker hypothesis Damasio.
Test using Iowa gambling task
Describe difficulties with episodic memory and self awareness in VPFC
Left - memory encoding
Right - memory retrieval e.g capgras
Describe difficulties associated with TOM and social cognition as a result of VPFC damage
Tom independent of ef (Rowe 2001)
Large studies indicate the involvement of orbitofrontal and media frontal areas (Stuss et al 2001)
But smaller studies fail to replicate (bird et al. 2004)
Executive functioning ax should consist of
Test of inhibition Executive memory and attention WM Multitasking Awareness Rule formation and shifting
Burgess and alderman 2004 advise we should not base assessment on neuro tests only as
The test environment is safe, structured with no distractions and may mask ef difficulties as there is a reduced demand on self planning and self initiation
Burgess and alderman 2004 advise observations and informants should be used in Neuro ax as
The individual may lack insight and an interview can consider impact on daily life and premorbid personality
Burgess and alderman 2004 dissociations in performance between executive tests are normal and very instructive.
The frontal lobes serve many functions, Des is misleading as symptoms do not invariably occur together. Natural to show patterns of impairment so failure on one test does not predict failure on another
Burgess and alderman 2004 caution not to over interpret difference in performance on two tests
Only consider differences if one score is very low (5th percentile) and the other is comfortably average. Consider patterns
Burgess and alderman 2004 failure on a test doesn’t mean fl damage
Ef varies within population and not diagnostic.
May be a pattern consistent with fl damage Burgess and alderman 2004 measuring function not brain integrity. This should be reflected in report
5 strategies to choose and plan neuropsychological assessment burgess and alderman 2004
- Time - more tests the better, cover more functions, due to ecological validity
- Psychometrics - hard with EF Tests to base on validity, widely used and with client group as traditional theory can be a poor indicator
- Expectation - base testing on what you expect to find
- Observation - base on symptoms observed
- Theory - theory led
