Brain mediation of emotional expression

Question 1

Spontaneous smiles involve…

Answer 1

contraction of the orbicularis oculi muscles whereas posed smiles do not - method acting

Question 2

Voluntary facial movement is dissociable

Answer 2

from emotional facial express

Question 3

Facial paresis

Answer 3

• difficulty making volitional facial movements on side contralateral to lesion in primary motor cortex or pathways to facial nerve
• full facial movements during spontaneous emotional expression

Question 4

Emotional facial paresis

Answer 4

• volitional facial movement intact
• weak or no facial movement during spontaneous emotional facial expression on side contralateral to lesion in insular, frontal white matter or thalamus

Question 5

Different brain mechanisms involved in

Answer 5

volitional facial movement and automatic involuntary emotional expression, even though both involve the same muscles

Question 6

Humor

Answer 6

1. Different types of jokes activate different areas of brain
2. But all activate R vmPFC

Question 7

R hemis also has dominant role in emotional expression

Answer 7

1. chimerical faces
   - L half composite was judged more emotionally expressive than R
2. emotional facial expressions usually emerge on the L side of the face first, suggesting > R hemis involvement (contralateral control of facial movement)
   - humans
   - monkeys
3. L hemis lesions usually do not impair expression of emotions in voice tone or facial expression, whereas R lesions often do
4. Case study of pt with bilateral amygdala damage.
   – Could produce facial expressions of various emotions including fear
   – Could not identify the emotion conveyed in a photo of herself showing a fearful expression