Emotions - Lecture 6

Front 1

Somatic Markers

Back 1

- Biasing signals generated from body, convey how rewarding or punishing an action is likely to be
- Shaped by experience (conditioning)
- Represented and regulated in emotion circuitry (affected by damage)
- Influences decisions by attaching emotional value to options
- Modulates cognition (memory, attention) and action (approach/withdrawal)
- Damasio

Front 2

Inducers of Somatic Markers

Back 2

- Primary: Both primary and secondary reinforcers (innate or learned stimuli)
- Secondary: Thoughts and memories induced by recall or imagination of emotional event

Front 3

The Body Loop

Back 3

- Somatic markers which reflect changes in the body
- Primary/Secondary inducers processed by Amygdala and vmPFC, which then communiate with 'effector' brain regions (hypothalamus, autonomic centres)
- These brain regions cause a change in bodily states, other regions that detect these changes (somatic markers) influence cognition and action

Front 4

The As If Loop

Back 4

- Somatic markers which reflect the brain's representation of the body
- Allows for speedier response
- Shortcut connection between effector regions and regions that detect changes (somatic markers)
- No bodily changes occur, but it's as if they do

Front 5

Somatic Marker Hypothesis

Back 5

- Emotion is the representation of complex array of homeostatic changes, occuring in different levels of brain and body in response to sensations
- Depends on conditioning history with given stimuli
- Predicts link between emotion, cognition and peripheral measures of somatic markers
- Predicts behavioural changes following amygdala and ventromedial prefrontal cortex damage

Front 6

Phineas Gage

Back 6

- Famous case of Ventromedial Prefrontal Cortex damage
- Unable to use prior emotion experience to guide decisions
- In complex situations, inability to predictreward andpunishments leads toinappropriate choices

Front 7

EVR

Back 7

- Suffered from brain tumour, leading to Ventromedial Prefrontal Cortex damage
- Unable to make decisions, especially social or personal
- Could not plan for future, chose unsuitable friends and activities
- Difficulty in expressing and experiencing emotions

Front 8

Bechara et al. (1999)

Back 8

- Iowa gambling task
- Bad deck of cards (A/B) vs. good deck (C/D)
- Dependent variables: selection of cards,physiological arousal (skin conductance response) when winning or losing money, physiological arousal prior to outcome revelation
- Not much physiological arousal for amygdala damage, compared to normal and vmPFC damage
- Because amygdala deals with primary inducers

Front 9

Chwalisz et al. (1988)

Back 9

- Spinal cord injury vs. other disability vs. non-disabled
- Structured interview, hypothetical situations invoking emotions and then comparison with past
- Spinal cord patients experience more fear and less love than in past
- Spinal cord injuries limit experience of bodily changes, yet there is little difference in other emotions
- Challenges somatic markers hypothesis

Front 10

North & O'Carroll (2001)

Back 10

- Spinal cord injuries played Iowa Gambling Task
- No difference between healthy and spinal cord injuries
- Challenge to somatic markers hypothesis
- Maybe facial nerves are enough to use as somatic markers

Front 11

Heims et al. (2004)

Back 11

- Pure autonomic failure patients play Iowa Gambling Task
- No body loop, maybe an as-if loop but probably not
- PAF patients did even better at choosing from good decks than bad decks, than controls did
- Challenge to somatic markers hypothesis

Front 12

Critique of James-Lange and Somatic Marker Hypothesis

Back 12

- Are bodily changes distinct enough to distinguish basic emotions?
- Secondary inducers produce weaker responses than primary, not explained by somatic marker hypothesis
- No conclusive evidence for reduced emotions following damage to bodily changes feedback
- Artificially induced emotions should produce stronger feelings of emotion

Front 13

Critique of Somatic Marker Hypothesis

Back 13

- Seems inefficient to have to go through the body to read emotions, why not use inducer + amygdala/vmPFC?
- Problems measuring explicit knowledge
- Problems with Iowa Gambling Task