Emotions, Stress, and Executive Function

Question 1

what are emotions? how do they differ from mood?

Answer 1

subjective, conscious experience that is characterized by psychophysiological expressions, biological reaction and mental states

• emotions influence how we act while moods influence how we perceive

Question 2

are emotions irrational? why or why not?

Answer 2

they are not irrational

• emotions are preserved among mammalian lineage, there is must be an adaptive value
• parts of the brain responsible for emotion are also responsible for decision making
• emotion is critically linked to how we value things
• disruptions that impair emotion also impair judgement and decision making
  • ex. psychopaths are worse at making decisions, don’t consider the right things when making decisions

Question 3

what are the two theories for emotion lateralization

Answer 3

1. right hemisphere model of emotion - right cerebral hemisphere is specialized for emotional processing
2. valence model - the two hemispheres govern different valences of emotion
   • left = positive emotions
   • right = negative emotions

• neither theory holds up well but we see small differences between hemispheres

Question 4

why do we sometimes think of emotions as discrete?

Answer 4

• paul ekman argued we have 6 primary emotions that are universal
• anger, fear, surprise, disgust, happiness, sadness
• in reality we found little consistency in how cultures rank emotions (except happiness)

Question 5

how do we think of emotions in terms of dimensions?

Answer 5

• think of emotions based on the dimensions of valence (pleasant vs. unpleasant) and intensity
• dimensions are thought to guide perception and action (approach/avoid)
• but, we sometimes approach unpleasant things (sad music) and are ambivalent about some things

Question 6

what are the brain regions of emotion?

Answer 6

• brain areas responsible for emotion are diffuse and overlapping
• population coding - one neuron can’t represent the emotion, the population of neurons firing represents the emotion/feeling
• it is hard to know if a brain area encodes a value or arousal or emotion

Question 7

what is kluver-bucy syndrome?

Answer 7

• removed the amygdala and part of temporal lobe of animals (anterior temporal lobectomy)
• animals presented very different behaviour
  1. lack of fear - would approach instead of avoid
  2. hyperorality - explored items by putting them in their mouths (problems with vision and recognition)
  3. misdirected hyper-sexuality

Question 8

how is the amygdala important in emotional learning?

Answer 8

• amygdala monitors the association between two different things (classical conditioning)
  
  • is a coincidence detector
• there is a high and low road to fear
  
  • high road is responsible for learning fear
  • low road

Question 9

how do the high and low roads to fear function?

Answer 9

• high road goes from thalamus to cortex before the amygdala
• low road goes straight from the thalamus to the amygdala

Question 10

how does damage to the amygdala affect fear (depending on location)?

Answer 10

• damage to lateral amygdala → impairs learning of fear association
• damage to central amygdala → impairs expression of learned fear

Question 11

who is patient SM and how did they experience fear?

Answer 11

• had a disorder where they had complete bilateral amygdala loss
• had no experience of fear and no learned fear conditioning
  
  • often approached fear stimuli instead of avoiding
  • interpreted arousal as excitement instead of fear
• could still experience fear under the right conditions, like when exposed to CO2 inhalation

Question 12

why could patient SM experience fear during CO2 inhalation but not under any other condition?

Answer 12

• amygdala is used to trigger a state of fear when we encounter threatening stimuli in the external environment
  
  • fear induced by internal stimuli are not controlled by the amygdala
• brain stem is responsible for introceptive fear-inducing stimuli

Question 13

how does patient SM represent the negative consequences of not experiencing fear?

Answer 13

• she had difficulty detecting threats and learning to avoid dangerous situations
• fear is adaptive, the amygdala promotes survival by compelling the organism away from danger using fear
• learned fear also helps us not make the same mistakes repetitively

Question 14

is the amygdala negatively valenced?

Answer 14

no

• in primate/rodent electrophysiology, the same amount of neurons that fire for aversive stimuli in amygdala, also fire for appetitive stimuli
• the amygdala is important in changing our values
  
  • during stimulus de-valuation (satiation) - if you get a good thing repeatedly, we start to de-value it
• we evaluate appetitive vs. aversive stimuli differently

Question 15

what other parts of the brain are responsible for fear?

Answer 15

• PAG - periacqueductal grey
  
  • part of the midbrain, tegmentum
  • one of the main recipients of the activity from amygdala
  • fear and shrieking behaviours
• ACC - anterior cingulate cortex (white matter?)
  
  • runs next to corpus collusum
  • activated during fear
• insula - hidden piece of cortex
  
  • can be seen inside the lateral fissure

Question 16

what is anger driven by?

Answer 16

• anger is largely driven by inequality
  
  • when fairness is compromised
• anger is prosocial, ensures people are treated fairly
• capuchin monkey gets angry after they see that the partner gets a grape while they get cucumber

Question 17

what is the ultimatum game and what does it tell us about anger and prosociality? how do we see this reaction in the brain?

Answer 17

• two player game where one play (actually a computer) divides money between themselves and another player, and the other player must accept or reject the offer and neither of them gets money
• as the split becomes more uneven, people reject the offer more often
• people say they want to punish the other person in hopes of better behaviour in the future, even at a cost to themselves (altruism)
• insula and anterior cingulate becomes more activated as more people reject offers (BOLD response)

Question 18

what is a homoeconomist?

Answer 18

• the economic human, we don’t correspond to rational economic behaviour
• we waste money and do things that don’t lead to best economic outcome

Question 19

what is the purpose of frustration?

Answer 19

to motivate us to try to go harder and further in the future

Question 20

what is the near miss effect?

Answer 20

• when you fail but are almost successful
• results in the largest frustration we can feel

Question 21

how does the near miss effect change behaviours on a slot machine task?

Answer 21

• when you have control of the arm of the slot machine, the near miss makes you more likely to play again (33%)
  
  • makes us feel we are in control
• a full miss makes you less likely to play again
• irrational overall because in a casino, having a near miss doesn’t necessarily mean we are getting closer

Question 22

what does brain activity look like during a near miss?

Answer 22

• anterior cingulate cortex activity goes up more for near misses vs. full misses
• anterior insula activity is correlated with subjective effects of near miss
• responses are enhanced in individuals with pathological gambling disorder

Question 23

what is a prefrontal lobotomy?

Answer 23

• procedure previously done to “reduce disruptive behaviour”
• usually done on people in psychiatric and prison institutions, women, and children
• put a orbitoclast into the prefrontal cortex and moved it around
• did not improve disruptive behaviour - some people had drastic changes and others had less

Question 24

what are some executive functions?

Answer 24

planning, organization, flexible thinking, monitoring performance, multi-tasking, self-awareness, motivation, determining and exhibiting appropriate behaviour, regulating emotion

Question 25

how does bilateral damage to the ventral prefrontal cortex affect executive function?

Answer 25

• vmPFC is known to regulate emotions
• lots of other executive dysfunction but most intellectual ability is preserved
• problems with prioritization, emotional dysregulation, repeating mistakes, planning, rigidity in thoughts/actions, attention and concentration

Question 26

how does unilateral damage to the ventral prefrontal cortex affect executive function?

Answer 26

• most detrimental dysfunction when damage is in the right side
  
  • disturbances associated with bilateral damage
  • more executive dysfunction
• people with damage to the left side will lead more normal lives
  
  • typical social and interpersonal behaviour
  • stable employment
  • personality relatively unchanged
  • decision making ability relatively intact

Question 27

who was phineas gage?

Answer 27

• medial prefrontal cortex had been damaged
  
  • previously thought that damage was bilateral, but there is more substantial damage in the left side
• lost fundamental aspects of his personality but still could maintain a job
• a decade after his injury, he developed severe epilepsy that ultimately led to his death

Question 28

what is passive vs. active stress?

Answer 28

• passive stress - something we need isn’t provided
• active stress - something happening to us

Question 29

how does controllable vs. uncontrollable stress affect us differently?

Answer 29

• stress immunization - exposure to controllable stress results in more resiliency to stress
• learned helplessness - exposure to uncontrollable stress results in less resiliency to stress in the future, even if it’s controllable

Question 30

what are the two physiological responses to stress?

Answer 30

1. stress is a sympathetic response - controlled by nervous system signal, moves fast and leaves fast
   
   • stimulates adrenal medulla and release norepinephrine into the body
   • causes heart to raise faster and blood vessels to dilate
2. stress is controlled by the HPA axis -controlled by hormones in the bloodstream, slower response that lasts longer
   
   • hypothalamus signals to pituitary gland that releases hormones
   • adrenal gland releases cortisol

Question 31

is stress beneficial or costly?

Answer 31

• stress is an adaptive response to threat
• mild levels of stress are beneficial but higher levels of stress have both costs and benefits
• when under high stress, we perform better in skills that are well-known but worse in skills that are new to us or not well-known

Question 32

what are the benefits and costs associated with high stress?

Answer 32

• benefits: improves implicit memory, simple tasks, habitual and well-rehearsed tasks, and short-term immune system suppression
• costs: compromises cognitive flexibility, working memory, executive functions

Question 33

how does catecholamine release relate to stress and arousal on the prefrontal cortex?

Answer 33

• there is a linear relationship between how stressed we are and how much catecholamines are released
• the affects of catecholamine release on performance look like the yerkes-dodson curve (based on arousal)
• with low levels of catecholamines, the prefrontal cortex fires less, is less likely to work together for a task, and is less discriminatory for what to fire for (easily distractible)
• at optimal levels of catecholamine release, the neurons create networks to work together and discriminate what to fire for
• in high stress, prefrontal cortex is suppressed and fires less while other parts of the brain (amygdala/basal ganglia) take on bigger roles
  • striatum is responsible for habitual behaviour and amygdala learns associations
  • high stress improves habitual behaviour

Question 34

what is chronic stress and how does it affect us?

Answer 34

• stress that is constant
• compromises immune functioning, mental health
• reduces hippocampal volume, thins PFC
  
  • reduces performance on hippocampal- or PFC-dependent tasks
• requires more PFC activity to have same level of performance
  
  • sends us further to the left of the yerkes-dodson scale
• shifts more reliance to subcortical structures (amygdala)
• may decrease baseline dopamine function
• effects often more pronounced in women

Question 35

what is burnout?

Answer 35

• loss of motivation and pleasure in things that were once enjoyable
• problems with irritability and looking ahead
• effects of chronic stress are reversible (restitution)

Question 36

what is the effect of the chronic stress of poverty?

Answer 36

• chronic stress of poverty affects executive functions, cost/benefit decision making, and ability to look ahead
• poverty affects cognitive performance on unrelated tasks
• exposure to irregular reward intervals guides individuals to act impulsively
  
  • even people with high baseline self-control
• poverty disproportionately affects children and their brains → less grey matter volume
• poverty is chronic exposure to uncontrollable stress → has an effect on the brain and learned helplessness

Question 37

what is ADHD? what affects diagnosis?

Answer 37

Attention Deficit/Hyperactivity Disorder (ADHD)

• extreme inattention, hyperactivity, impulsivity
• intersects with development, maturity, and societal norms (2x more boys than girls)
• girls and women more often the inattentive subtype and potentially underdiagnosed
• youngest children in class are 40% more likely to be diagnosed with ADHD because they’re more immature compared to peers (overdiagnosed)
• diagnoses have increased more than 100% since 2007

Question 38

how do we treat ADHD?

Answer 38

• psychostimulants (amphetamine, methylphenidate) improve symptoms
• medications block DAT and NET, increasing functioning of these systems
• are stimulants but somehow improve hyperactivity

Question 39

how can we explain why psychostimulants improve symptoms of ADHD? what parts of the brain look different in people with ADHD?

Answer 39

• people with ADHD sit further on the left of the Yerkes Dodson curve
• low levels of catecholamine activity in PFC, firing less often, less integrated, and less discriminatory (more distractible)
• PET studies suggest DA system is hypoactive, but there are no changes to norepinephrine
• many studies suggest changes to PFC, DA system, and basal ganglia
  • symptoms of ADHD relate directly to executive function

Question 40

how can we differentiate adult ADHD from chronic stress and burnout?

Answer 40

• all three result in less catecholamine release and sitting further left on yerkes dodson curve
  - symptoms also overlap
• ADHD may also increase risk of burnout
• requires nuanced diagnosis