Lecture 12: Dysfunction related to emotion, stress, and executive function

Emotion

Characterized primarily by psychophysiological expressions, biological reactions, and mental states

Emotions influence how we act; Moods influence how we perceive

Long history of emotions supposedly clouding judgement

Emotions vs. “logic”: It’s not logic. Logic is based on certain facts, and we don’t know any certain facts

Emotions vs. “reason”,

Emotions as “irrational”: emotions as “compromising judgement”

Emotions are quite rational → leads to better outcome (lack of emotions → poorer outcome)

Charles Darwin: Emotions selected for! Emotions are advantageous, that’s why we all still have emotions, or they would’ve disappeared due to evolutionary purposes

Most of 20th c.: understudied

Emotion

Characterized primarily by psychophysiological expressions, biological reactions, and mental states

Emotions influence how we act; Moods influence how we perceive

Long history of emotions supposedly clouding judgement

Emotions vs. “logic”: It’s not logic. Logic is based on certain facts, and we don’t know any certain facts

Emotions vs. “reason”,

Emotions as “irrational”: emotions as “compromising judgement”

Emotions are quite rational → leads to better outcome (lack of emotions → poorer outcome)

Charles Darwin: Emotions selected for! Emotions are advantageous, that’s why we all still have emotions, or they would’ve disappeared due to evolutionary purposes

Most of 20th c.: understudied

Are emotions irrational

Central thesis: Emotion is critically linked to value

Parts of the brain that are related to emotions are the evitibly related to values (You have to know values of things to make decisions)

Disruptions that impair emotion also impair judgment and decision making

Right Hemisphere model

“Right brain responsible for emotions (right brain person Vs. left brain person)”

Wrong, cuz bilateral neurofunctional imaging in emotions, you can see that ppl who have damage in left hemisphere see deficits in their emotions as well as damage in the right hemisphere

Valence model

“Right hemisphere for negative emotions, Left for positive emotions”

From neuroimaging you can see that not all the “bad” stuff lines up in right and “good” stuff lines up in the left

Damage to the right hemisphere leads to higher mood baseline level!

Damage to the right hemisphere leads to ____

A higher mood baseline level

Dimensions of emotion

Some (e.g. Paul Ekman) argue for discrete emotions

Universal emotions: Happy, disgusted, fear, anger, Sad, purprised

• Newly added: shame and pride

• Happiness is the most generally consistently agreed upon. Even animals and ppl with blindness smile.

Others suggest emotions are comprised of dimensions (e.g. valence and intensity–high to low intensity)

These dimensions are thought to guide perception and action (e.g. approach/avoid)

Why approach sad music? Why approach frustration? What about ambivalence? This is why sadness is not something we avoid!

Regions of emotion

Diffuse, overlapping yet distinct

Many, big areas. There’s no “happy” or “sad” brain area.

BOLD level in the brain is related to positive values. We still don’t know if these areas encode value or emotion or both.

Often not 1:1 for function:cell: Population coding: You need a large amount of neurons to process complicated feelings/emotions

Population coding

You need a large amount of neurons to process complicated feelings/emotions

Kluver-Bucy syndrome

Removed anterior temporal lobe (which includes amygdala) in non-human primate (prey species, need to have fear, like of snakes)

• Near complete loss of fear (go straight to grab snakes, and physically investigate humans – which they’re supposed to be scared of both snake and human)

  • Thought to be due mainly to amygdala damage

• Hyperorality (pick up things they’re investigated in their mouth)

• Misdirected hypersexuality (inanimate objects or other species)

• Repeatedly investigating familiar objects

All of this is maybe due to perception issues (that’s why they have to put things in their mouth–repeatedly to perceive better)

Hyperorality

Pick up things they’re investigated in their mouth (Overly investigating things in mouth) due to lack of fear

Classical FEAR conditioning

Rat hear tone and get an electric shock

Sound predict that the shock is coming → rat learned to be scared of sound and freeze, preparing to get shocked

Damage amygdala → can’t learn to be scared of the sound. But it’s not consistent

Fear arrives at what amygdala and process (express fear) at what amygdala

Lateral amygdala (where everything arrives, learn fear) → central amygdala (express fear)

Now, if remove lateral amygdala, impair in learning fear conditioning, but it doesn’t always impair the ability to express fear conditioning. So if alr learned to be scared of smth, as long as there’s still central amygdala, in some studies, the animal still express fearful behavior

There’s 2 pathways of learning to be scared of things: High roads vs. low roads

Lateral amygdala

Learn fear

Central amygdala

Express fear

If have this but no lateral amygdala, if alr have old fear conditioned, you still can express fear

Damage to sensory cortex

Sound of car vs. washing machine → damage → can’t distinguish which sound to be scared of

BUT, Sensory cortex removed, still can learn fear conditioning

High roads

Sensory info arrives at thalamus → cortex → amygdala

Learn how to be scared of certain things (like canvas notifications and not Finch notifications). Called high road cuz it’s consciously the highest cortical function

Low roads

Sensory info arrives at thalamus → directly amygdala

Doesn’t require conscious processing, but it provokes feeling. Very fast

Patient SM

Complete bilateral amygdala loss: This patient Amygdala get destroyed since a kid, discrete (not like strokes)

Unable to learn fear conditioning: But can still experience it under the one right condition; Not getting enough air (CO2 inhalation) (we don’t know why)

Impaired quality of life: Trust ppl too easily, get robbed, live in unsafe area, no sense of personal space

Other patients with amygdala damage have less fear impairment than patient SM (maybe cuz age at damage onset? SM had this damage way early in life)

Is the amygdala negatively valenced?

Primate/rodent electrophysiology (record when u present things to animals)

Roughly equal numbers of cells that respond to appetitive (positive, like delicious) versus aversive (negative, like needle) stimuli

Some cells respond for both (i.e. for arousal, not valence)

Often implicated in updating value (not fixed system) E.g. During stimulus devaluation (satiation)

Eat first donut = it’s so good, second = uhh it’s so unhealthy, third = it’s too much now I’m เลี่ยน, don’t want it anymore

Functional utility of fear

Benefit your judgment in decision making

Do animals have stimulus devaluation?

Animals don’t show this. Keep eating chocolate over and over without feeling disgusted

Appetitive versus aversive values: Speed to learn positive things vs. negative things

We learn to slowly about positive things (e.g. trust someone, what’s the best coffee shop), but we learn QUICKLY about negative things (e.g. danger, who’s a red flag)

Small punishment “worth” a large reward? → Makes interpretation difficult

Fear is more than the amygdala

Emotional activation in the brain is large, distributed, and overlapping

All lobes of the neocortex

Heterogeneity in results (due to methods/evocation of emotion?)

PFC usually important

Functional utility of anger

Encouraging fairness, subtly prosocial behavior

This study: Monkey gives a rock in trade of food

• Give cucumbers to 2 monkeys in the 2 cages

• Now, give cucumber to left monkey (he gets mad), and grapes to right monkey

Ex. Ultimatum game

Ultimatum game: Proposer and responder

Proposer: Gets a sum of money (e.g., $10) and proposes how to split it between themselves and the other player. It’s a computer, but responders don’t know.

Responder: Can either accept or reject the offer

Ultimatum game: Result

From Homoeconomicus sense, the responder should get the $1 cuz it’s better than 0 (in the economic view, you would be “irrational” if you don’t accept $1)

Reject any offer cuz if u punish them by not giving them any money, to teach them that it’s not fair. So anger could be altruism – guiding to prosocial behavior! Like หวังดี to change the unfair person to change their behavior.

When they know it’s a computer, they’re more likely to accept the money (like stubbing your toes to the bed. You’re not gonna get angry at your bed for long)

Ultimatum game: Activated brain region during rejecting unfair offers

Anterior insula BOLD correlates with rejecting unfair offers

Functional utility of frustration

Intense motivation, galvanial behavior. (ex. Hit 7 reps last set in shoulder press → frustrated → motivated to hit 8 or even 10 reps next set)

Ex. Slot-machine task and Near-Miss Effect

Slot-machine task: Near-Miss Effect

The Near-Miss Effect: Almost success, but lost at the last moment → intense frustration (like getting a 79 on a final. Like come’on just roll up to 80!!)

Most motivated (spend max amount of time & money & energy) when hit near-miss 30% of the time! (and casino’s slot machine are planned to hit near-miss 30% of the time!!!)

Slot-machine task: Brain regions activated during near-miss (2)

Anterior singulate cortex BOLD higher for near-miss than fullmiss

Anterior insula BOLD correlated with subjective effects of near miss (the more each person feel more frustration/anger) (same as when responder rejecting offer in ultimatum game)

Phineas Gage: Impairment? Health? Unilateral or bilateral brain damage? Cause of death?

He maintained a job as a horse-carriage driver (which is a pretty complicated job) in Chile and based on his doctor, he had good health, no sign of impairment!

Previously thought to have bilateral damage (from skull damage cuz we didn’t have his brain), but more recently thought unilateral (after running a computer model)

A good example of recovery, and similar to contemporary patients

Ultimately, he developed severe epilepsy and died (due to epilepsy later in life, not the personality change and all that)

The prefrontal lobotomy: Methods and results

NO CLEAR RESULTS of therapeutic intervention in the 20th CE. Some had little to no effect, some had moderate effect

Lobotomy is Orbitoclast (like a pick) go through nose and behind the eyes and to the prefrontal lobe and damage (swish up) that area

The guy who came up w this had the idea based on ONE study on chimpanzee that had this lobotomy (and it lost frustration during hard task) → used on ppl who have “disruptive behavior”🤨! So dangerous!

Executive functions overview

All in diff regions across the prefrontal cortex

Better predictor of success than IQ score (attendance is another major predictor of success)

• Planning

• Organization

• Flexible thinking

• Monitoring performance

• Multi-tasking

• Solving unusual problems

• Self-awareness

• Learning rules

• Social behaviour

• Decision making

• Motivation

• Initiating appropriate behaviour

• Inhibiting inappropriate behaviour

• Regulating emotions

• Concentrating

Executive dysfunction: bilateral vmPFC damage

• Commonly studied: vmPFC damage

• But executive dysfunction can happen from a variety of PFC damage

• Most intellectual ability preserved (meningioma – cuz it grows both sides, hemorrage)

• Problems with prioritization (i.e. how to meet a short term and long term goal))

  • There’s this person with tumor that got fired from the job cuz they spent the entire day organizing the files instead of getting the work done.

• Emotional dysregulation: Ex. Acquired sociopathy

• Repeat mistakes despite often “knowing” it’s suboptimal

  • Like gambling fallacy – choose that deck of card that didn’t have good card last pick (preserverative behavior)

    Loss of “get up and go” (being able to put on shoes and just go to work): Attendance is another major predictor of success

  Problems thinking ahead, sequencing steps for a task

  Rigidity in thoughts and actions

  Problems with attention and concentration

Acquired sociopathy

In some dementia – like lack of empathy, impulsivity, and disregard for social norms (like saying racist things that they used to hold back)

Most studied brain damage

Bilateral prefrontal damage, cuz it’s more commonly observed in patients

Executive functions: Unilateral vmPFC damag

Use overlay (overlapping structural MRI) method

Right Side (more severe executive dysfunction impairments that left)

Left Side (Seem to be not too bad)

• Typical social and interpersonal behaviour

• Stable employment

• Personality relatively unchanged

• Decision making ability relatively intact

Basically, damage to which side of brain leads to more executive dysfunction impairments

Right side than left

Disturbances just described i.e. Executive dysfunction

Stress

Can be significant life events, good and bad(e.g. moving home, death of a loved one, marriage)

Not just a crisis, but also “the daily grind” (Lazarus, 1981), lives of “quiet desperation”

Can be active or passive, short-term or long-term

Effects often more pronounced in women (more severe in women for response to stress)

Removing the stressors tend to lead to a much better outcome than stress mediation techniques

There’s the reality of “burnout” and “hustle culture” BUT these effects are shown to be reversible!

Active stress

Engaging in smth that’s actively happening. Involves direct engagement in a challenging task, typically requiring physical or mental effort to achieve a goal

• (like Restraining the rats to not move around)

• Taking exam, Arguing with subletter

• Controllable

Passive stress

Stress that results from smth that you usually need is withdrawn from you. Results from a lack of control over a negative or threatening situation; the person is more of a bystander than an active participant.

• Parental neglect, stuck in the traffic, waiting for the bad news, social isolation

• Uncontrollable

Which stress is worse? Active or passive?

Active stress is just as bad as passive stress. Have similar effects on us (our nervous systems)

Acute stress

Short term stress. We have nervous systems that are designed for this type of stress → navigate the world better

Stress immunization

Exposure to controllable stress (your actions, like final papers that you have piling up) in the present → more resilient to future stress, even if it’s out of your control

Learned helplessness

Repeatedly exposed to uncontrollable stress (like generational poverty, adverse childhood exp) → less resilient to future stress, even if it’s in your control

How is stress related to cortisol release

Cortisol is always released (it has the baseline level of being released, it fluctuates according to circadian rhythm), but stress affects it

Physilogical faster response to stress

Sympathetic response! Rapid, governed by adrenal gland to release more adrenaline and norepinephrine to do thing like increase heart rate, reduce saliva production, etc.

Physilogical slower response to stress

HPA axis (Hypothalamus, Pituitary, Adrenal)! Hypothalamus releases hormones to Pituitary → Pituitary releases hormone into bloodstream → ex. activate adrenal glands

Acute stress has some drawbacks, but how is it generally beneficial for us

Stress is an adaptive response to threat!

Mild levels of stress are beneficial across the board (every domain in cognition and behavior)

• Counting 1.. 2.. 3.. to make your child clean up → better job

• The Jay’s tiny bomb on the screen during midterms → better time management

Test for humans play game as rats to go through maze to find the exit from the water, turns out humans, just like rats, stress made them performed better

Benefits of higher levels of acute stress

Increase implicit memory, simple tasks, habitual and well-rehearsed tasks

Greater Immune system for short-term! But when stress goes down a bit, the immune system gets back to normal → getting tiny flu during final season

Drawbacks of higher levels of acute stress

Impair cognitive flexibility, working memory, executive functions

Stress is generally beneficial when acute, especially for our habits and skills, but detrimental when chronic (more in a sec)

Implication for your studying and exams

Professionals (like professional tennis player, or national cubic solver) perform better under high levels of acute stress (like putting them in front of 2000 ppl watching), because it’s their well-learned skills and habits after lots of training (not me tho, cuz tennis is not my well-learned skills and habits, I’d perform the worse match of my life under that level of stress)

So to get a better score on test, you have to practice and practice to get used to it!

Stress affects the prefrontal cortex (PFC) via catecholamine release (DA–Dopamine and NE–norepinephrine)

Relationship between stress/arousal and performance (Yerkes-Dodson curve)

Linear relationship of stress and catecholamine release (more catecholamine – DA and NE – release = more stress)

We all have different levels of baseline catecholamine function (in average, men sit more on the left side – bored, underaroused – than women, maybe that’s why they like doing risky stuff to get more aroused?)

More catecholamine release (stress) in prefrontal cortex → neurons used to fire lots of things now fire for one thing, inhibit in prefrontal cortex (becomes quiet) → less executive function

Comes to why we seek out activities that make us experience diff levels of arousal (like reading a book or try bungee jumping

Explain stress/arousal and behavioral/cognitive change according to the Yerkes-Dodson curve

Low level of catec: Drowsy (Not enough arousal and productivity, bored, low pressure)

• Neurons in PFC are distractible – not enough activity(not focused on one task)

Moderate level: Best performance. Perfect level of arousal

• Neurons now fire for one thing (focused on one task = productive)

High level: Stressed, less executive function

• Neurons stop firing in PFC → networks disconnected, and PFC becomes silent

What happens when there’s too much level of stress/arousal

PFC is silenced (Cuz neurons stop firing in PFC and networks disconnected), basal ganglia (skills and habit) kicks in! → makes us focus on the present than future.

E.g. That’s why it’s important to practice doing quizzes before exam so it becomes habits and under high level of stress during the exam, even your PFC shuts down, basal ganglia comes into rescue!

Chronic stress: Brain and PFC changes

Reduces hippocampal volume, thins PFC (executive functions, etc.) (like losing dendritic spines, not neuron, so losing grey matter)

• Reduces performance on hippocampal- or PFC-dependent tasks

Requires more PFC activity to achieve the same level of performance

Shifts more reliance to subcortical structures (e.g. amygdala)

May decrease baseline DA function (to the left of the curve, in response to you being always stressed out) → too stress even at the supposingly the “best performance” level of catecholamine release

BUT! Once you overcome it (like months of recovery) these brain changes and mental problems are REVERSIBLE

The chronic stress of poverty (low SCS – socioeconomic status)

Poverty affects:

• cognitive performance on unrelated tasks (13 points less IQ)

• Immune, endocrine, nervous system health

• Put attention less on goal-directed behaviors, more on habitual behavior (basal ganglia in effect when PFC silenced at high stress, makes u focus on present than future) → Short-sighted and risk-averse decision-making

Exposure to irregular reward intervals guides even individuals with high baseline self-control to act impulsively

Exposure to unpredictable bus schedule (i.e. bus being 2 hrs late) (like ppl in low SCS not knowing when they’ll have financial win) leads to to the level of impulsivity that ppl w low scs ppl have

Poverty affects which population the most, neurologically?

Children. Leads to less grey matter!

ADHD: Symptoms and diagnosis

Extreme inattention, hyperactivity, impulsivity, in a way that affects negativity in success

Intersects with development, maturity, and societal norms

Girls, women, and marginalized indv. are underdiagnosed

Adult diagnoses of ADHD have risen more than 100% since 2007 until 2019

ADHD: Who’s more at risk

5-11% of children & teenagers receive diagnosis, boys 2x > girls in children/teens

Younger children in class ~40% more likely to be diagnosed with ADHD

• Maybe due to self-fulfilling prophecy, younger kids in class are more perceived as immature → actually conform to that idea

Ppl who born in August are more at risk

Adult population: 2.5-3%: men 1.6x > women in adults

Medication for ADHD. What does it do? (Related to the Yerkes-Dodson curve)

Psychostimulants (DA agonist) (amphetamine, methylphenidate) improve symptoms

At low doses, psychostimulants give modest cognitive benefits to most of us, not just those with ADHD

It blocks transporter of DA (DAT) & NE (NET), and increase function of catecholamines (T as transporters) and move their baseline level to the right side to reach the optimal level of arousal

This is because ADHD ppl’s baseline level of catecholamine is at left side of the Yerkes-Dodson curve

Overlap between ADHD and chronic stress/burnout

Symptoms overlap

At low doses, psychostimulants provide modest cognitive benefits to most of us, not just those with ADHD (hard to acheive the right dose, and too high dose leads to bad outcomes)

Burnout symptoms for those with ADHD

And ADHD may also increase risk of burnout (Turjeman-Levi et al. 2024)

Requires nuance in interpretation

>50% of ADHD social media posts classified as misleading (Yeung et al. 2022)

In any case, reducing chronic stressors will benefit most of us

Patient SM

A rare individual with focal, bilateral amygdala lesions since a kid.

Study aim to measure her subjective experience of fear

At floor level (very low fear) across: Phobia scales, Panic disorder symptoms, Public speaking anxiety, Death anxiety. Electronic diary for 3 months = Rated fear-related emotions (afraid, nervous, scared) near 0% of maximum possible

SM wasn’t emotionally numb. She showed curiosity and excitement instead of fear.

Behavior matches monkeys with amygdala lesions (Klüver-Bucy syndrome)

Her past exp: Held at gunpoint and knife-point, Assaulted, Victim of domestic violence, Lived in dangerous, crime-heavy areas, Despite real danger, she showed no urgent fear behaviors

From studying patient SM, amygdala damage disrupts… (2)

1. Amygdala damage disrupts sensory representation → fear triggering pathway

2. It also disrupts the link between external stimuli and emotional action programs