19. Amygdala and Emotions

June 10, 2015 by Dr. Tangen Leave a Comment

When I see a bear do I run because I’m afraid or am I afraid because I run?

As it turns out, there are more than two answers to this classic riddle. Emotions are part of our human experience and central to our understanding of how we see ourselves.

But there are multiple theories of emotion and no clear answers. But it appears that thinking is more important to feeling than we thought it was.

Here’s what is included in this lesson:

how to identify emotions in animals
how to identify emotions in people
amygdala and its role in emotions
theories of emotion
basic emotions

Read chapter 8 of Kalat’s Biological Psychology Here are the resources you need:

SLIDES

TERMS

amygdala
anger
anterior insula
anxiety
bare teeth
basic emotions
basolateral complex
body sensations (heart rate, etc)
classical conditioning
cognitive mediation theory
common sense theory
component process model
contamination
cross-cultural
cultural rules
depression
disgust
display rules
distress
dropped jaw
eeuu!
emblems
emotion
emotional pain
emotional state
engagement (flow)
expressions
facial expression
fear
fear conditioning
fight or flight
freeze (immobility)
gender differences
gestures
happiness
I see bear
intensity = how much jaw drops
James-Lange theory
meaning (quest for something bigger)
medial nucleus
memory consolidation
micro expressions
mirror-neuron matching system
no = shake head left-right
not quite words
nucleus amygdalæ
on alert
perception of danger
PERMA (Martin Selligman’s)
phobias
placebo (saline)
PTSD
puh
pupil size
relationships
sad
self-monitoring
startle response
surprise
theories of emotion
two factor theory
underestimate risk
Wundt

NOTES

Limbic System
- Thalamus
- Hypothalamus
- Pituitary
- Pineal Gland
- Amygdala
Amygdala
- Also called nucleus amygdalæ
  - Almond-shaped groups of nuclei
  - Medial temporal lobes
  - Part of basal ganglia?
  - Processes emotional memories
  - Linked to both fear & pleasure
- Several structures
  - basolateral complex
  - cortical nucleus
  - medial nucleus
  - central nucleus
- Output =
  - Hypothalamus
  - Activates sympathetic nerves
  - Thalamic reticular nucleus
  - Increases reflexes
  - Trigeminal & facial nerves
  - Expressions
  - Activates dopamine, epinephrine and norepinephrine
- Memory formation & storage
  - Memories of emotional events
- Mediate long-term signal potentiation of neurons?
  - Memories of emotional exper. trigger fear behavior
  - Freeze (immobility)
  - Stress hormone (heart rate…)
- Damage
  - Impairs classical conditioning
  - Both acquiring and expressing
  - Pavlovian fear conditioning
  - Positive reinforcement
- Classical conditioning
  - Separate neurons for pos. & neg., not anatomically different
  - No clear wiring plan
- Memory Consolidation
  - Convert to long-term storage
  - Learning can occur without it
  - Help regulate hippocampus?
  - Strength of emotion impacts strength of memory
  - Add stress hormone after learn, recall better (at least in rats)
- What amygdala does
  - Evaluate significance of stimuli
  - Generate emotional responses
  - Generate hormonal secretions
  - Generate autonomic reactions come with strong emotions
  - Involved with?
    - Post-traumatic stress disorder
    - Depression
    - Phobias
    - Anxiety
    - Autism
    - Anything Emotional
Emotions
- What Is Emotion?
  - Category of stimuli
    - high significance to an individual
    - high arousal (strong feelings)
    - subjective response
    - quick & automatic
  - Sympathetic nervous system
  - Prepares for brief-vigorous action
  - Parasympathetic
    - alters activities to save energy and prepare for long-term
  - Strong emotions increase readiness to act
- Identifying Emotions
  - Facial Expressions
  - 10,000 expressions
  - 40 muscles
  - Voluntary
    - Making movement doesn’t always cause emotion
  - Involuntary
    - Some are same across cultures
  - Display rules vary
    - Quickly cover up
    - Some are same across species
- Micro Expressions
  - Less than a second
  - Examples
    - Surprise is shortest expression
    - Who is worried?
    - BBC program: The Human Face
- Gestures
- Emblems
  - Differ by culture
    - Yes = nod head up and down
    - No = shake head left-right
  - Egyptian culture
    - Tomorrow = hand loop
    - After tomorrow = two loops
  - Distress = hands on head (one pat other)
- Not Quite Words
  - Puh
Basic Emotions
- Hard-wired
- Can feel more than one at once
  - Wundt
    - Classified along two dimensions
      - Pleasant or unpleasant
      - Level of activation (arousal)
- No agreed upon list:
  - Fear
  - Anger
  - Disgust
  - Sad
  - Surprise
  - Happiness
Fear
- Decrease in skin temp (cold-feet)
- blood flow to feet?
- Includes:
  - Thoughts (worries, etc)
  - Physical sensation (heart, breath)
  - Behaviors (run, escape, avoid)
    - “fight or flight”
  - Heart
    - Increased force & rate
    - “pounding heart”
  - Muscles
    - Increased tension
  - Sweaty-cold palms
  - Nausea & diarrhea
  - Tremors
- Fear Conditioning
  - Even minor $ can cause fear
  - Un-erasable fear response?
  - PTSD
  - Rat is shocked (electrical)
    - Fears stimulus
    - Fears old cage & new cages
    - Fears new situations
  - Humans
    - Attacked or trauma
    - More fearful in many situations
    - Generalized emotional arousal
    - Stimulus generalization
- Amygdala
  - Makes associations of events with emotional sensations
  - Mediate long-term signal potentiation of neurons?
Anger
- Characteristics
  - Eyebrows together
  - Eyes glare
  - Narrow lips
  - Causes increase in skin temp (hot under the collar)
  - blood flow to arms
- Display Rules
  - Animals
    - Make loud sounds
    - Try to look larger
    - Bare teeth
    - Stare
  - Humans
    - Display as social manipulation
    - Cultural rules
- Impacts
  - Less self-monitoring
  - Less objective observations
  - Increased activity in left hem.
  - Particularly frontal & temporal
- Lateral orbitofrontal cortex
  - Inhibits anger
  - Approach motivation
  - Positive affective processes
  - Underestimate risk
  - Believe ventures will succeed
  - Feel less likely for heart disease
  - Feel more likely get raise
  - More prejudiced against outsiders
  - Less trusting
  - On alert
  - Look for other attacks
  - Anticipate more angry events
  - Not sad events
Disgust
- Revulsion
- Withdraw
- Contamination
- Seen is all cultures
  - different cultures find different things disgusting
  - Cross-Cultural
  - Widely recognized
  - Shown by
    - slightly narrowed brows
    - curled upper lip, wrinkling nose
    - stick out tongue
  - Children
    - 5-month olds avoid toy parents make negative faces at
    - Until 10, interpret it as anger
- Related to sense of taste-smell
  - disgusted by inharmonious
  - Impact
    - Facial expression
    - Moldy milk
    - Eeuu!
  - Triggered if people look ill?
    - Feces, urine, body fluids
    - Blood & gore
- Gender differences
  - Women more than men
  - Especially sexual disgust
  - Also thinking about dentists
- Anterior insula
  - Activated by unpleasant tastes, smells and images
  - Active when disgusted
  - Active when nauseated
  - Damage to anterior insula
  - Can’t experience disgust
  - Trouble recognizing facial expressions of disgust
  - Mirror-neuron matching system
  - Triggers in us what we see in others
  - Intensifies moral judgments
  - Those people are more guilty
Sad
- Emotional pain
  - Temporary (depression chronic)
  - Loss, despair, helplessness
  - Crying
    - Crying is bad criterion
  - Separation from parent
    - Sad
    - Afraid
  - Pupil size
    - Faces with small pupils rated more sad
    - Your pupil size smaller when sad
- Depression
  - Sad, anxious, empty, hopeless
  - Aversion to activity
  - Lose of interest
Surprise
- Shortest expression
- Brief emotional state
  - unexpected event
- Is long-lasting surprise shock?
- Characteristics
  - Raised eyebrows
    - curved and high
    - most important cue
  - Horizontal wrinkles on forehead
  - Dropped jaw
    - Intensity = how much jaw drops
  - Open eyelids
    - See whites of their eyes
  - Lasts fraction of a second
    - Followed by fear, joy, etc.
- 1. Hard to fake expression
- 2. Hard to fake feeling
  - Raising eyebrows won’t give feeling
- Startle response
  - Reaches pons 3-8 ms
  - Followed by reappraisal
  - shift emotion to joy, etc.
Happiness
- Martin Selligman’s PERMA
  - Pleasure (tasty food, warm bath)
  - Engagement (flow) (challenging activity)
  - Relationships
  - Significant others
  - Spending money on others
  - Meaning (quest for something bigger)
  - Accomplishments (completed tangible goals)
- Damage to brain reduces it
  - Huntington’s disease
  - Parkinson’s disease
  - Multiple sclerosis
  - Epilepsy
  - Stroke
- No validated way to increase
- Don’t know how to substantially improve long-term happiness
Theories of Emotion
- Components
  - Body sensations (heart rate, etc)
  - Perception of danger
  - Emotion (fear)
  - Behavior (run)
  - Stimulus
- 1. Common Sense
  - See a bear
  - Feel fear
  - Run
- 2. James-Lange
  - See the bear, run, feel fear
  - Emotion is interpretation of physiological $
    - I run, therefore I am afraid
  - Action first, think about it later
  - Find ourselves trembling, experience fear
  - But internal organs are relatively insensitive
    - Can’t respond quickly
  - Feedback from them could account for our feelings of emotions?
    - Theory difficult to verify experimentally
    - Emotion is a label
    - ANS and skeletal actions occur before emotion
    - I see bear, run, then feel fear
- 3. Two Factor Theory
  - Schachter and Singer
    - Ss told given vitamin shot
    - Received either
      - adrenaline or placebo (saline)
    - Put in room with another person (experimenter)
      - Took cues from person with
        
        playful
        
        angry
    - Need both bio reaction and cognitive cues
  - I see bear
    - I feel sensations
    - I see what other people are doing
    - If they are afraid, I am afraid
  - I see bear
    - I feel sensations
    - Use cues to determine what I think trembling caused by
    - Fear
- 4. Cognitive Mediation
  - Component process model
  - Brain senses lots of things
  - Make low-level appraisal of rel.
  - Triggers bodily reactions, behaviors & feelings
- I see the bear
  - I think I’m in trouble
  - I breathe fast, run, and feel fear
- Cognitive awareness is fast
  - Brain can categorize events as pleasant or unpleasant as quickly as 120 ms

QUIZ

1. Which are characteristic of surprise:
- a. horizontal wrinkles on forehead
- b. raised eyebrows
- c. dropped jaw
- d. all of the above
2. How much a jaw drops is a measure of:
- a. concreteness
- b. abstractness
- c. intensity
- d. all of the above
3. The R in Selligman’s PERMA stands for:
- a. reminiscence
- b. relationships
- c. reverse
- d. reward
4. Which brain area inhibits anger and risk:
- a. lateral orbitofrontal cortex
- b. premotor frontal cortex
- c. medial occipital cortex
- d. M1
5. When angry, some animals try to:
- a. avoid eye contact
- b. reason with you
- c. remain quiet
- d. look larger