Prefrontal Cortex and Executive Functioning Flashcards
What are some of the functions of the frontal lobe?
Motor control
Language
Higher level cognition
- Executive functioning
What kind of presentation can a lesion in a particular nucleus of the thalamus lead to?
Similar to what you’d see if lesion in connected cortical area
What is the difference between lobotomy and locotomy?
Lobotomy = removal of tissue Locotomy = severing of connections
What is the anterior unit in Luria’s functional systems?
Prefrontal cortex
What is executive function?
Inter-related processes responsible for goal directed, purposeful behaviour
Includes emotional and social behaviour, and cognition
“Frontal lobe” function
What are the areas of the prefrontal cortex responsible for executive function?
Lateral
Orbital
Medial
Does damage to each area responsible for executive function present the same way?
No
Which part of the prefrontal cortex is usually tested, in regards to executive function?
Usually only lateral function routinely tested
What does the dorsolateral prefrontal cortex do?
Working memory Response selection Planning and organised Hypothesis generation Flexibility maintaining/shifting set Insight Moral judgement
What supplies the dorsolateral prefrontal cortex?
Largely middle cerebral artery
What is working memory?
Keep information in mind and manipulate it a little
What is response selection?
What is best response in this situation?
What is planning and organising?
How to carry out simple tasks; eg: making cup of tea
What is hypothesis generation?
Reason through different solutions to a problem
What is flexibility maintaining/shifting set?
Maintain train of thought but shift if need to
What does the medial prefrontal cortex do?
Emotional-motivational interface
- At most extreme: akinetic mutism
- Apathy
- Lack of initiative
- Indifference
What is the blood supply of the medial prefrontal cortex?
Anterior cerebral artery
What is akinetic mutism?
Lack of desire to talk > don’t talk at all
What does the orbitofrontal prefrontal cortex do?
Highly connected to limbic areas Inhibition - Emotional - Cognitive - Social Impulsivity
What is the blood supply to the orbitofrontal prefrontal cortex?
Anterior and middle cerebral arteries
Which area is the last to develop in the brain?
Frontal lobe
Which area is the first to degenerate in the brain?
Frontal lobe
Which abilities are amongst the last to reach maturity?
Executive functions
- Lower order functions develop first
- Higher order develop later
In which order to executive functions develop?
- Theory of mind
- Cognitive flexibility
- Inhibitory control
- Affective decision-making
- Working memory
Are executive and frontal lobe dysfunction the same disorder?
No
What is important to note when thinking about executive dysfunction?
Can occur because of disruption at any level of system; eg: executive symptoms from subcortical lesions
What are the positive symptoms of executive dysfunction?
Distractability Social dysinhibition Emotional instability Perseveration Impulsivity Hypergraphia
What are the negative symptoms of executive dysfunction?
Lack of concern Restricted emotion Deficient empathy Failure to complete tasks Lack of initiation
How are medial and orbitofrontal prefrontal cortical lesions formally assessed?
Difficult to do
Clinical judgement
History taking
What executive dysfunction does the “tower of London” test?
Disinhibition and problem solving
In dysfunction
- Disregard rules
- Can’t figure out strategy to complete task
What executive dysfunction does the “stroop test” test?
Disinhibition
What executive dysfunction does the “Rey complex figure test” test?
Planning deficit
What are some common causes of executive dysfunction?
Closed head injury Stroke Psychiatric conditions Dementias Focal lesions Inflammatory Developmental
