PSC 135 MT3 L13

What role was the amygdala thought to play in each decision process?

Amygdala mediates frame effect where subjects choose the "sure" or "gamble" option based on the frame of a gain or loss. "Increased activation in the amygdala was associated with subjects. tendency to be risk averse in the Gain frame and risk-seeking in the Loss frame, supporting the hypothesis that the framing effect is driven by an affect heuristic underwritten by an emotional system." You see a difference in amygdala activation as a fcn of the frame. What you are afraid of is becoming a sucker and taking the loss which is why you chose the gamble. In the loss frame, you are afraid of loss and go for the gamble.

implicit fear conditioning paradigm

Before training, if you have a light (benign stimulus) it won't cause the rat to behave in anyway. But if there is a light in the room and then a shock in the ground it will elicit fear in the rat. When the rat is afraid it jumps. The rat experiences an association between the benign stimulus and the shock. The light then becomes the conditioned stimulus and the jumping that the mouse does in response to the light becomes the conditioned response. It trains the rat to be afraid of the once benign stimulus. -Unconditioned stimulus (US): shock -Unconditioned response (UR): startle or jump -Conditioned stimulus (CS): light (experimentally paired with US) -Conditioned response (CR):anticipatory fear in response to CS This can also be seen in a second study with blue squares. -Blue square comes on and after an interval, subject receives a shock. -Shock is unconditioned stimulus (US). Pain is unconditioned response (UR). -Blue square is the conditioned stimulus (CS). What happens in the future when subject sees the blue square? Subjects usually show CR: increased skin conductance response (i.e. sweat) at sight of blue square (the CS). ( Galvanic skin response)

Instructed Fear Paradigm

Fear responses can also be learned explicitly from knowledge -Instructed fear paradigm: Subjects normally show increased SCR and increased amygdala activity at sight of blue square (without shock). -Amygdala patients report rule but do not show physiological response -You don't need to expose person to a situation but you can tell them about it. Ex every time you see a blue square you are going to get a shock. So that when they do see a blue square they start to sweat. A hippocampal patient comes into the experiment and will not sweat because he won't remember what has been told to them (immediately)

Financial decision game

Gambling in the face of guaranteed gain vs. loss. "framing effect" Objective probability of winning at a gamble is the same; The amount of money in sure option is also the same. But, people more likely to gamble when sure option is presented as a loss (62%) compared to a gain (43%). Situation where you have to make a decision whether you are going to gamble. It is a financial decision making task. You receive 50 pounds. You see a sign that you can keep 20 pounds or gamble ( if you keep 20, you will lose still lose 30). In the Loss frame, you receive 50 pounds and then you will lose 30 pounds or you would gamble. ( you will lose 30 and keep 20. These are identical but are worded completely different. Behavioral results: Subjects were were much more likely to gamble when given the "loss frame"

What is the ultimatum game?

One participant is given money, which he must split with another player who can accept or reject the offer (but not control offer). -Fair offers: around 50% -Unfair offers: less than 50% -But getting something is better than nothing... right? -Unless you are being taken advantage of (sucker)? The sense of being taken advantage on depended on whether the player was a computer or a human. You don't feel taken advantage of by a computer, so odds are you are more likely to have a higher acceptance rate of whatever money a computer offers you. But this isn't the case with humans. -Unfair offers evoke more activity in bilateral insula, but this effect was not seen when the offer came from a computer -- Negative correlation between insula activation and likelihood of accepting offer. -Negative emotion will lead to rejection of offer even though it is not rationale. Perhaps to protect social standing.

How would patients with damage to the hippocampus vs. amygdala differ in their: (1) knowledge of the stimulus-shock association and (2) their fear response upon seeing the conditioned stimulus?

Rats with amygdala lesions: UR intact, but do not express CR. Do not learn relationship between CS and US. Rats with amygdala lesions would still get startled (UR) in response to the shock ( US) but would not get startled in response to the light (CS) because it won't learn the relationship between the CS and the US. In blue square with humans... amygdala patients- Fear of learning will break down when the patient sees the blue square. Patient is named SP. Does not show the CR. She does respond knowing that the blue square will lead to shock which hurts. HP patients- When a hippocampal patient is tested in this paradigm- Hippocampal patients learn associations fine but they have no declarative system that they have been in the experiment before. If you show them the blue square they will start to sweat, as if knowing a shock will happen, even though they don't remember this from previous experiments. Patients with amygdala damage don't have the physiological response. Hippocampal damage can still do the implicit task, if you damage your amygdala you have no memory problem.

What is one explanation for why she not have perceived fear expressions?

SM does not use information from the eyes for any emotion. Impairs identification of fear, sadness the most (contrast with happiness, which can be inferred by the mouth). •Amygdala directs attention to eyes. They had SM and controls look at faces and tracked their eyes as they were doing so. The found that SM did not look at the eyes of the face she was looking at, unlike controls- Identification of fearful expression improves when instructed to look at the eyes. -we see that SM performs well identifying other emotions besides fear, so there isn't an issue with the identification of emotions in general, only a specific deficit in recognizing fear. When it comes to identifying fear, SM performs poorly, but when instructed to look at the eyes, SM improves significantly.

What were the consequences of her lack of fear on social interactions?

SM has difficulty judging trustworthiness of others-also personal space and stereotypes -SM engaged in an experiment. A culturally specific experiment where they have ppl walk up to a person and you want to talk to them and you stop and talk to them. The average person knows when someone is standing too close to you.. SM stood at a distance at about half of the distance from her cultural counterparts. She stood closer.

Social Fear and cognitive reappraisal

Suggests that we have implicitly learned things.This is a study in which individuals were looking at faces. What they found was whether or not these ppl had an interaction with a black male, there is some kind of fear learning that has been associated with a black male face and fear. After time, activations of the frontal lobe happened - Cognitive reappraisal. You can still have a response to something but you can also modulate what you feel with what you know.

Insula and Disgust processing with decision making

The insula encodes feelings of disgust and may be involved in "irrational" decision making for things that we feel are unfair. These types of results suggest that emotions play a big role in decision making, which has traditionally been neglected for more "cold" cognitive processes

What are the findings from SM that illustrate her lack of ability to feel/perceive fear

Woman; 38 yrs old (in 2005); lesion of all nuclei of amygdala bilaterally; most all other subcortical structures intact. Normal perception, memory, language, reasoning. Lack of conditioned fear response; social behavior is overly trusting and friendly -lost her ability to understand emotions generally. She does pretty much fine except identifying what afraid looks like. She will misattribute it to something else -when asked to draw emotions, drew everything fine except for fear she drew a baby

Moral decision game

Would you be willing to sacrifice one life to save five lives? Would your decision be different if you had to (a) pull a switch to direct a trolley toward one person or (b) physically push a person off a footbridge into the path of a trolley car? Research suggests that the strong emotional response to actually pushing someone would make you decide differently in these two scenarios. . In this problem, a conductor loses control of his trolley car (Figure 13.28). As a witness to this event, you can see that, if nothing is done, five people are likely to be killed because they are directly in the path of the speeding trolley. You can throw a switch and divert the trolley onto another track. This option, however, comes at the cost of ensuring the death of a single construction worker who is on the alternate track. Do you throw the switch or not? Now consider the footbridge dilemma. This time you are standing next to a large stranger on a footbridge that crosses over the tracks. You see an out-of-control trolley car speeding toward five people. This time, the only way to stop the trolley car is to push the person next to you off the footbridge onto the tracks to impede the movement of the trolley car. Do you push the stranger onto the tracks in order to save the other five people? Most people agree that is acceptable to throw the switch in the trolley dilemma, but they find it immoral to push the stranger in the footbridge dilemma. In both cases, one person's life is sacrificed to save five others, so why do we make such different choices? we make different choices in the trolley and footbridge dilemmas because the level of personal involvement in causing the single death differentially engages emotional decision making. If you throw a switch, you still maintain some distance from the death of the construction worker. When you actually push the stranger, you perceive yourself as more directly causing the death. fMRI studies revealed personal dilemmas and impersonal dilemmas were associated with distinct patterns of activation. Impersonal: lateral prefrontal cortex, parietal lobe Personal: medial frontal, posterior cingulate gyrus and amygdala Moral decisions influenced by emotional outcomes.

Which area is involved in processing disgust?

insula part of limbic system -Feeling disgust from seeing pictures of rotten food, rotten smells, poor hygiene activates insula Seeing a face that is experiencing disgust:The more disgust the face shows the greater the response from the insula. Insula does not respond so well to a neutral faces but the more a face looks disgusting the more activation.