dysfunction affecting, emotion, stress and executive functions

301 final

Davidson on emotions

emotions influence how we act, moods influence how we perceive

value and emotions

the areas in the brain that process emotion also process evaluation, if we disrupt emotion we also disrupt evaluation

right hemisphere model

mainly comes from case studies with problems in the right hemisphere that asserts the right hemisphere is dominant for processing all emotions

valance model

right hemisphere is specialized for negative emotions while left is for positive emotions

discrete emotions

all human beings feel some basic emotions and all other emotions are built from this

dimensional emotions

emotions have a valance and intensity and these guide perception and action (e.g. approach/avoid)

emotions regions in brain

many big areas, overlapping yet distinct, motor region (behaviour), sensory (change in perception), cortex and thalamus (conscious change), amygdala hippocampus hypothalamus (change in physiology and learning)

kluver-bucy syndrome

loss of amygdala leading to loss of fear expression, hyperorality, misdirected hypersexuality

amygdala in emotional learning

acts as a coincidence detector. where information converges

high road

pathway that goes from sensory organs → thalamus → cortex → amygdala and requires conscious processing

low road

pathway that goes from sensory organs → thalamus → amygdala. less sophisticated and doesn’t require conscious processing

patient SM

has extremely rare genetic condition that leads to a complete loss of amygdala. No experience, understanding, or physiological indication of fear. (except when exposed to high amount of CO2)

function of fear

leads to good judgement and keeps us safe even when we don’t understand why

what amygdala measures

intensity rather than valance (neurons fire for both negative and positive stimuli), value change (e.g. how first bite of food feels vs last)

visually induced fear

increased activity in the amygdala

conscious experience of fear

happens in the cortex level and thalamus

function of anger

promotes subsequent fairness and outcomes that are beneficial to the community

traditional economic rationality

humans are driven to maximize their profit. In the ultimatum game, the responder should always accept because any money is better than none.

BOLD activity in the ACC

correlates with anger and is higher during near miss instead of full miss situations

BOLD activity in anterior insula

correlates with offer rejections in the ultimatum game and subjective effects of near misses in gambling

frustration function

increases out motivation to be successful, specially when we experience near misses

illusion of control in gambling

leads to more frustration which encourages people to continue gambling

executive functions

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

bilateral vmPFC damage

changes in social behaviour, personality, and decision making, while often leaving basic cognitive abilities intact (walking, talking, etc…)

acquired sociopathy

massive negative personality change due to PFC damage

unilateral vmPFC damage

right side causes EF impairment while left has a higher likelihood that aspects of life will remain normal

active stress

stress that is done to us (e.g. tail pinch in animal models)

passive stress

getting deprived of something we need to flourish (insufficient money, maternal neglect, social isolation)

acute stress

short term stress that can be beneficial

long term stress

harmful since our brain are only built with stress for a prolonged amount

controllable stress

stress with an outcome that is determined by our behaviour(e.g. taking an exam)

uncontrollable stress

stress with an outcome that can’t be determined by our behaviour (being born into poverty)

stress immunization

becoming more resilient to future stress as a result of exposure to controllable and acute stress

learned helplessness

becoming less resilient to future stress as a result of exposure to uncontrollable or long term stress

sympathetic NS (aka SAM axis)

fight or flight, frees up energy and makes ATP to prepare, signals travel along axons and target the adrenal gland

inner adrenal gland

releases epinephrine and norepinephrine

parasympathetic NS (aka HPA axis)

slower response since it doesn’t act through the neurons. Instead the hypothalamus releases a hormone onto the pituitary gland that then travels through the blood stream until it reach the adrenal gland

outer adrenal gland

changes cortisol levels, more about determining things over a long course

stress benefit

simple mild stress can cause us to perform better in tasks and high levels will cause our best learned abilities to flourish

high stress in EF

less cognitive flexibility and worse working memory

catecholamines

dopamine, norepinephrine

stress in the PFC

linear relationship between stress and catecholamine release in the PFC, but curvilinear effects

low arousal

low catecholamine release, PFC neurons fire a bit and for a wide range of stimuli (unfocused and distractible)

optimal arousal

more catecholamine release, PFC neurons fire more and work in a coordinated way like a network, more selective for what they fire for

high arousal

high catecholamine release, dopamine and norepinephrine will silence the PFC (neurons stop firing)

chronic stress leads to

constant suppression of immune system, mental health disorders, PFC thinning, hippocampus thinning

cause of impulsivity in chronically stressed people

reliance gets shifted to basal ganglia and amygdala, lower in baseline catecholamine release

effects of irregular reward intervals

more impulsive behaviour even in people who score high in EF tasks

ADHD key components

extreme inattention, hyperactivity, impulsivity

psychostimulants

drugs that increase function in monoamines (catecholamine and serotonin) such as amphetamine and methylphenidate as a treatment to ADHD by bringing up levels of arousal

ADHD neuroimaging

difference in PFC, DA system, and basal ganglia