L15 Psyc 211 emotion 2 Flashcards
The Role of the Ventral Prefrontal Cortex
§ The PFv has inhibitory connections with the amygdala which are responsible for suppressing emotional responses in social situations.
§ In the mid 1800’s, Phineas Gage was a victim of a tragic construction accident.
§ An explosion sent a 3 cm thick, 90 cm long tamping rod through his face, skull and brain.
§ Before his injury he was a good natured, kind, responsible, well liked and respectable man.
§ After his injury, he became childish, irresponsible and thoughtless of others. He had severe temper outbursts and used profane language. He was unable to make plans or carry them out. He lost his job and was unable to keep a social network of friends.
Could not regulate or us emo in proper context and did not even realize future consequences of his particular behaviour.
The Ventral Prefrontal Cortex,
High high seat of cognition, complex behaviours
Regulates responses to emotions, not so mcu detecting fear like Migdalia does.
§ The ventral prefrontal (PFv) cortex consists of the orbital prefrontal (PFo) cortex and the ventromedial prefrontal (PFvm) cortex.
§ The PFo is located at the ventral surface of the frontal lobe and covers the brain above the eye orbits.
§ PFvm lies adjacent to PFo. It occupies the medial extent of the ventral surface.
§ Inputs from amygdala, the hippocampus and other temporal lobe structures, the ventral tegmental area and the olfactory system provide the PFv with information about the environment and future planning.
§ Outputs to cingulate cortex, hypothalamus, hippocampus and amygdala influence the regulation and expression of emotion.
The Ventral Prefrontal Cortex and Decision Making
Role?
§ Patients with PFv damage make decisions that are rewarding in the short term but lead to detrimental effects in the long term (e.g. gambling)
§
The Iowa Gambling Task
Bechara et al., (1997; 1999) had subjects play a gambling card game.
§ Subjects were given a stake of $2000 play money and were instructed to win as much as possible.
§ Subjects had to draw cards from one of four decks. Two were good decks and two were bad decks.
§ Selecting cards from the ‘good’ decks lead to low rewards but low penalties.
§ Selecting cards from the ‘bad’ decks lead to to high rewards but high penalties.
Bad Decks
a. Gain $100; one half of all cards also have penalties averaging $250
b. Gain $100; one-tenth of all cards also have penalties of $1250
Long term losses!
Good Decks
c. Gain $50; one half of all cards also have penalties averaging $50
d. Gain $50; one-tenth of all cards also have penalties of $250
long term gains
Results from The Iowa Gambling Task
see skin conductance, shwing stress
§ Control subjects showed changes in skin conductance associated with ‘emotional stress’ just before they chose a card from the bad deck.
§ Control subjects eventually shifted their responses from bad decks to good decks. That is, they let their emotional response guide their choice behaviour.
§ Patients with PFv damage (especially PFo damage) did not show signs of stress ‘before’ they selected from the ‘bad’ deck but showed autonomic changes ‘after’ they made a choice that cost them money.
§ Patients with amygdala damage failed to show any emotional changes before or after the choice of cards.
§ Thus, emotional responses are important in guiding our decisions.
fMRI scans of healthy controls and psychopaths during emotional conditioning training (Birbaumer et al., 2005)
§ Subjects were presented with a picture of a man’s face paired with a painful stimulus.
§ Control subjects show autonomic signs of emotional conditioning (e.g. galvanic skin response) and activation of the amygdala, PFo and PFvm and insula.
§ Psychopathic subjects fail to develop a conditioned emotional response and little sign of brain activation. No fear of future consequences?
Facial Expression of Emotions is
Innate,
This means?
§ Human expressions are innate, unlearned responses involving complex movements of the facial muscles.
§ Ekman and Friesen (1971) showed that an isolated tribe in New Guinea were able to recognise emotional expressions by westerners.
§ They were also able to produce expressions that were recognisable by westerners
Expression play role in social functions, telling others how we feel.
Anger, fear, surprise and sadness!
“It’s all about the FASS, bout the FASS” and disgust? And clap if happy?
Words in language are arbitrary!
Recognition of Emotion: Role of the Amygdala
display only useful if can be recognized
§ Effective emotional communication is only useful if other people can recognise one’s emotional state.
§ Damage to the amygdala impairs the ability to recognise facial expressions of fear.
§ Increased amygdala activity when people view fearful faces, not happy faces.
§ Superior colliculus and pulvinar input to the amygdala enable facial recognition (not input from the visual association area).
§ Patients with damage to the visual cortex, who have no conscious awareness of looking at a person’s face, show activation in the thalamus, superior colliculus and the amygdala when viewing fearful faces.! No conscious perception remember.
Amygdala is involved in recognition, not expression of fear as demon sated by?
§ Patient S.P. received a bilateral amygdalectomy to treat a severe seizure.
§ She can recognise individual faces, but she is unable to recognise emotional expressions of fear.
§ Intriguingly, S.P. is able to produce her own expressions of fear and several other emotions.
§ But, she cannot recognise a picture of herself expressing fear
So, Recognition likeley learned, despite expression being innate only for FEAR
Viewing ‘fearful’ eyes activates the amygdala
§ On their own, eyes convey valuable emotional information.
§ Viewing fearful eyes without any other facial features is sufficient to activate the amygdala (Whalen et al., 2004).
Recognition of Emotion: Eye movements and fixations
Control Patient
§ Control subjects spontaneously look at and examine the eyes of a face to detect the emotional state of the person they are interacting with.
§ S.M. is a patient with bilateral amygdala damage studied by Adolph et al., (2005).
§ When shown photographs of faces, S.M. failed to look at the eyes.
Can train her to look at eyes and recognize emotion, they need constant reminder.
Perception of Direction of Gaze, warning sign
Neurons in a monkeys’ superior temporal sulcus (STS) increases firing rate when it looks at photographs of another monkey or human ‘gazing’ in a particular direction.
Gaze direction is informative; it tells us if the emotional expression is directed toward us or someone else.
If someone expresses fear, it can serve as a useful warning but only if we can figure out what the person is looking at. Towards us need to know.
Gaze up particularly sensitive to.
Aside: eye gaze experiment toddler,
Autistic with normal.
Normal look eye,
Autistic do not look eye
Not diagnostic.
Amygdala damage in autism just one aspect. But no animal model
Animals help calm child, bond relates to the child.
Recognition of Emotion: Role of Imitation
Somatosensory damage, less empathy?
Aside on mirror neurons. Responsive, mirror neuron system evidence is weak. There are mirror neurons though.
§ There is an association between emotion recognition and activity in the somatosensory cortex (Adolph et al., 2000).
§ Patients who are unable to recognise and identify facial expressions of emotions typically have severe damage to the somatosensory cortex.
§ This suggests that when we see a facial expression of an emotion, we unconsciously imagine ourselves making that expression. That is, we imitate what we see.
§ The somatosensory cortex provides a representation of what an emotion may ‘feel’ like.
§ Knowing what it feels like to make a perceived expression, helps us recognise the emotion being expressed in the face we are viewing.
Expression of Emotion
§ Facial expressions are automatic and involuntary.
§ Genuine happy smiles involve contraction of muscles around the eyes.
§ Actors have to imagine the desired emotion and once evoked, the facial muscles follow naturally.
§ People with volitional facial paresis are unable to voluntarily control facial muscles but can express genuine emotion with those muscles. The reverse is true of people with emotional facial paresis.
Volitional facial paresis Emotional facial paresis
