Sarah's Section Flashcards
Prefrontal Cortex Subdivisions: Dorsolateral Prefrontal Cortex
Executive functions:
- Working memory (the ability to hold in mind information that isn’t immediately available in the environment)
- Response selection
- Planning and organising
- Hypothesis generation
- Flexibly maintaining or shifting set
⭐Neuropsychological tests are well-designed to test these functions
⭐️Damage to this area would make us stimuli-bound
⭐️Left-sided; language mediated
❤️Largely supplied by the middle cerebral artery
Prefrontal Cortex Subdivisions: Medial Prefrontal Cortex
Emotional - Motivational Interface
Higher level attention (anterior cingulate)
Damage causes:
-Extreme: akinetic mutism (patients just sit with no initiative)
-Apathy: indifference, lack of concern about wellbeing
-Indifference
-Decreased self-awareness and thus an inability to identify nuances in conversation, tend to misread what others eldest and may say inappropriate things. There is an overall unawareness of one’s internal states and an inability to regulate intraceptive and emotional information, as well as an inability to envision what another may be feeling in the moment and take perspective (⬇️ToM)
⭐️Tests aren’t as good, but the development of tools called social cognition look promising
❤️Supplied by the anterior cerebral artery
Prefrontal Cortex Subdivisions: Orbitofrontal Cortex
Highly connected to limbic areas- can downregulate the functioning of the limbic system
⭐️A lack of downregulation associated with damage to this area is typically experienced as a lack of emotional regulation, which could present as emotional instability or unpredictability.
⭐️Inhibition
- Emotional
- Cognitive
- Social
⭐️Impulsivity (failure to downregulate/inhibit a function)
In a Matching Familiar Figures task, OFC lesions had more errors despite faster reactions times.
❤️Supplied by anterior cerebral artery and middle cerebral artery
Symptoms of Executive Dysfunction
➕ Symptoms
- Distractibility
- Social disinhibition
- Emotional instability
- Perseveration
- Impulsivity
- Hypergraphia
➖Negative symptoms
- Lack of concern
- Restricted emotion
- Deficient empathy
- Failure to complete tasks
- Lack of initiation
Neuropsychological Testing:
Verbal Fluency
Orthographical lexical retrieval (OLR):
High level verbal working memory task
Patient is required to remember as many different words as they can (e.g. “How many words can you think of that start with the letter “F”?)
⭐️Idea generation task = core function of the DLPFC
Neuropsychological Testing:
Tower of London
⭐️Person must plan
They only have 4 moves to get from their position to the goal position.
Neuropsychological Testing: Rey Complex Figure Task (RCFT)
⭐️Tests visuo-perceptual spatial function in those with right parietal lesions/disturbance. But as it involves PLANNING, it can assess the PFC.
Neuropsychological Testing:
Stroop Test
⭐️Tests inhibition
Neuropsychological Testing:
Wisconsin Card-Sorting Test (WCST)
⭐️Sensitive to set-shifting/flexibility from one to another which is a DLPFC function
Rules change as to how the cards must be sorted, assessing one’s ability to shift and adapt.
Subdivisions of the frontal lobes: Prefontal Cortex
- Dorsolateral PFC (@ front)
- Orbitofrontal (‘ventromedial zone’) PFC
- Medial PFC (midline, on the inner surface of brain)
Cognitive Control
⭐️Planning, controlling, and regulating the flow of information processing across the entire brain.
Executive functioning
- Processes essential for goal-oriented behaviour
- Planning based on past experience
- Performance monitoring and correction
- Regulates information processing across the brain networks
- Hierarchical processing (from anterior to posterior)
Neuropsychological assessment:
Dorsolateral prefrontal cortex:
Working Memory
⭐️Delayed-response task
Monkey is shown food people presented in 1 of 2 trays, then a screen comes down and the monkey is required to maintain in memory where the pellet is. The screen then lifts and the monkey makes response. If they’re able to do this task successfully, WM is in tact. 👍
Maturation of the Frontal Lobes
⭐️FL is the last area of the brain to develop at around early adulthood (early 20s) and is also one of the first to degenerate in the ageing process.
There are positive (neuronal proliferation, myelination) and negative processes (pruning).
@adolescence: neural connections aren’t fully myelinated.
⭐️Processes for cognitive control are among the last to reach maturity.
Anxiety
Behavioural treatments:
- Systematic desensitisation/in vivo exposure
- Progressive Muscle Relaxation Training (PMRT): allows us to induce a state of relaxation physiologically