Executive Function

Question 1

where does executive function reside?

Answer 1

PFC

Question 2

delay gratification

Answer 2

• Hide reward from you
• Hide yourself from reward
• ‘Cool down’ reward
  o Blowing on it
• Use distractors
  o Singing, taking pictures

Question 3

Cognitive control: Casey et al. 2011

Answer 3

• Ability to ‘delay gratification’ aged ~4 predicts future
  o Educational performance
  o Ability to cope with stress and frustration
  o Parental evaluation of success
  o SAT scores (University entrance exam)
  o Body Mass Index
  o Use of crack cocaine
  o Performance on a similar task aged 40+
   Activation of nucleus accumbens
• (Stanford Marshmallow Experiment)
  o Kids can have one marshmallow now, or 2 if they wait.

Question 4

explanations for the delay gratification experiments (not cognitive control)

Answer 4

Trust, reliability, and predictability:
- Manipulation of the marshmallow test
- More reliable = more trust = better on marshmallow test

Question 5

role of PFC in exectuive function

Answer 5

• Generate mental representations without sensory representation
  o Working memory
  o Abstract reasoning
  o High-order, flexible decision making
  o Executive functioning

Question 6

Yerkes-Dodson principle:

Answer 6

• Impacts of stress on cognitive performance
• Depends on how complicated the task is
• As stress increases, performance on simple task increases
• As stress increases, performance on difficult task increases until optimal stress but any extra stress impairs performance.

Question 7

Positive effects of stress:

Answer 7

• Low-level stress can increase attention
  o Salience and vigilance
• Zeigarnik effect
  o Uncompleted tasks are remembered more easily than completed tasks (stress still there and the task nags at us)

Question 8

Stress impairs prefrontal function (Arnsten, 2010): explain

Answer 8

• Stress: mediated by increased catecholamine release (especially noradrenaline)
• Fatigue
• Alcohol
• Results in poor decision-making (relapse)

Question 9

Symptoms of frontal cortex damage:

Answer 9

• Difficulty planning sequence needed to complete a task (e.g. make a cup of tea)
  o Requires working memory
• Loss of spontaneous interactions
• Loss of flexibility in thought
• Perseveration – persistence of a single thought or action
• Inability to focus on the task in hand
• Emotional lability
• Abulia – passivity, apathy
• Socially inappropriate behaviour
• Personality change
• Difficulty with problem solving
• Expressive aphasia
• Hemiplegia

Question 10

Dorsolateral PFC: role

Answer 10

• Brodmann Area 46 (and 9?
• Working memory
• Abstract reasoning
• Top-down regulation of attention
• Projects to hippocampus
  o encoding Long Term memory
  o Recalling memory to ‘replay’ in DLPFC
• More rostral = more abstract
  o Metacognition + Morality

Question 11

Ventromedial PFC: role

Answer 11

• Brodmann 25
• Regulation of emotion
• Representations of reward and punishment
• Calculates ‘value’
• Visceral inputs re pain and suffering
• Outputs back to limbic system then on to autonomic
• Supplied by ACA
  o Orbitofrontal and Frontopolar branches

Question 12

Orbitofrontal PFC: role

Answer 12

• Brodmann 10, 11 and 47
• Decision making
• Impulse control
• Processing reward, punishment and value
  o E.g. secondary gustatory cortex
• Supplied by ACA and MCA
  o Orbitofrontal branch (ACA) lateral orbitofrontal branch (MCA)

Question 13

Oxycontin was supposedly…

Answer 13

• Less likely to result in a ‘high’, therefore
• Less addictive
  o Less prone to ‘abuse’ (recreational users would ‘not want’ to take it)
  o Less prone to ‘diversion’ (no market for it)
• Less likely to cause withdrawal
  o At lower doses

Question 14

oxycontin - how could this lead to less addiction - flaws?

Answer 14

• Oxycontin is slow-release oxycodone
  o Coated tablet rather than powder (could be completely bypassed by just smashing the tablets up into the original powder form!)
  o Fewer peaks and valleys than with immediate-release oxycodone (supposedly)

Question 15

Extended-release mechanism of oxycontin

Answer 15

• Oxycodone is embedded in a matrix
• Tablets are coated to slow their digestion
• Slow down the release of oxycodone into blood/brain
• ‘proven’ with pharmacokinetic studies
• To get the same dose over a longer period
  o Need more oxycodone per tablet