Emotion

Psy391h - Classes 22-23

(This page last updated 26 April 2006.)

To study interactions between cognition and emotion we have to start with a particular emotion. Following LeDoux, we will focus on Fear.
- Fear is pervasive (even though we face danger much less often than our ancestors).
- The role of fear in psychopathology.
  - anxiety
  - phobias
  - obsessive-compulsive disorder
  - panic disorder
  - post-traumatic stress disorder
- Expression of fear in humans is similar to that in other animals.
- Neural structures underlying fear seem to be similar across species.
- Easier to produce fear in the lab than other emotions.
LeDoux starts by finding the neural circuits underlying fear.
To study the brain mechanisms of fear, neuroscientists must have a particular framework within which to work. Many have used Fear Conditioning.

Social and emotional decision making
Damage leads to "utilization behavior"
- driven more by environmental cues
With damage, lack of skin conductance response (SCR or GSR) to emotional stimuli.

Damage to right temporal-parietal region can impair understanding of emotional prosody in spoken language.
Interpreting facial expressions relies more on right hemisphere.
Separate neural pathways for spontaneous and voluntary facial expressions.
- Only left hemisphere can trigger voluntary facial expressions.
  - Connection through callosum to right cortex to trigger left side of response.
  - Damage to right hemisphere can block voluntary expression on left side.
- Either hemisphere can trigger spontaneous facial expressions.
  - Pathways for spontaneous expressions damaged in Parkinson's disease, but not pathways for voluntary expressions.
Lateralized EEG and affective style
- People with stronger midfrontal EEG signals on left than on right generally report more positive feelings.
- People with stronger EEG on right generally report more negative feelings.
- Approach behaviors more associated with left hemisphere, while withdrawal behaviors more associated with right.