Problem 7

Question 1

Extensionality

Answer 1

Logical consistency across decisions regardless of the manner in which available choices are presented is central to rational decision making

Question 2

Framing effect

Answer 2

Human choices are sucebtible to the way in which objects are presented/framed

ex.: 75% lean meat is usually preferred over 25% fat meat, even though they are the same, just framed differently.

Question 3

Martino et al investigated the neurobiological basis of the framing effect by means of fMRI.

Explain their financial decision-making task

Answer 3

Particpants recevied a message saying they would receive 50$

2. Subjects had to choose between “sure” option vs “gamble option
3. These 2 options were presented in 2 different frames

“sure” option
–> keep 20 out of 50 (Gain frame) vs lose 30 (Loss frame)

“gamble” option
–> 40% of winning vs 60% of losing

Question 4

What was the result of martinis financial decision making task ?

Answer 4

Participants were

1. Loss aversive in the Gain frame
2. Risk seeking in the Loss frame

AND: participants seemed highly unaware of the biasing effect

Question 5

It is hypothesized that the framing effect is driven by an affect heuristic that is underwritten by an emotional system.

How was this confirmed by the financial decision making task ?

Answer 5

There was significant activation in the bilateral amygdala when making decisions based on heuristics

–> thus plays a central role in mediating the frame effect

Question 6

Imagine you usually take your car to work but today you decide to use the ferry.

Which brain part is activated when we make decisions that are different to our general behavioral tendencies. ?

Answer 6

The ACC

Question 7

Decreased susceptibility to the framing effect and thus enhanced rationality in decision making is related to which brain region ?

Answer 7

Orbital + medial PFC

–> specifically right OFC + vmPFC

= OMPFC

Question 8

Elaborate on the role of the amygdala in decision making.

Answer 8

1. Value-related precision + learning both negative/positive outcomes
2. Mediation of decision biases that come from value-related prediction
3. Detection of emotionally relevant info present in contextual + social-emotional cues

AND now added: It processes the type of contextual positive or negative emotional info that is communicated by the frame

Question 9

What is the role of the OMFC in decision making ?

Answer 9

1. Incorporates inputs from the amygdala
2. Represents the motivational value of stimuli

=> allows it to integrate + evaluate the incentive value of predicted outcomes to guide future behavior

Question 10

Lesions to the OMPFC will lead to … ?

Answer 10

Impairments in decision making

–> inability to adapt behavioral strategies according to the consequences of decision

THUS: impulsivity

Question 11

What is the primary contribution of the amygdala-vmPFC interactions according to Hampton et al ?

Answer 11

Computing expected reward values

–> once established, these are then used to generate behavioral decision

Question 12

Behavioral choice

Answer 12

Whether to maintain current choices or switch choices

• -> 1. posterolateral OFC
  2. Anterior insula
  3. ACC

BUT: these signals are reduced in subjects with amygdala lesions

Question 13

Computation of expected reward value

Answer 13

How much money one expects to earn or lose based on the choice one made

–> done by vmPFC

Question 14

Value of the outcomes

Answer 14

Actual monetary gain or loss at the end of the decision making process

Question 15

The production of signals in

1. OFC
2. ACC

that are related to behavioral choice directly rely on input from …. ?

Answer 15

Amygdala

Question 16

Reversal learning

Answer 16

Requires a subject to flexibly adjust their behavior when the reward-related contingencies that they have previously learned are reversed

Question 17

How does the decision making process work in reversal learning ?

Answer 17

1. vmPFC computes expected reward
2. These signals are used to determine whether to
   a) maintain choice
   b) switch

Question 18

On what basis did Hampton et al conclude on the functional significance of the interactions between the amygdala + vmPFC ?

Answer 18

Neural representations on the expected reward in OMPFC/vmPFC depend on input from the amygdala

–> if amygdala is lesioned these signals in mPFC are abnormal

THUS: these signals can no longer be used appropriately to generate behavioral decisions

Question 19

Location of the amygdala in primates

Answer 19

In anterior temporal lobe towards its medial side

–> almond shaped; part of telencephalon

Question 20

Positive vs negative reinforcement

Answer 20

Something one works to obtain or avoid

Question 21

1. Misconception:

Amypdala funcitons primarily in negative affect

Answer 21

Amygdala encodes positive values AS OFTEN as negative ones

–> role of the amygdala for positive emotions is at least as important as its role for negative ones

Question 22

Evidence from rat + money studies that amygdala also encodes postive affect ?

Answer 22

Anticipatory period
–> visual properes of food served as CS predicting its availability

Consummatory period
–> actual access to food

Bilateral lesioned monkeys showed:

1. No CS-induced cardiovascular response during anticipator period
2. Intact motor response during anticipatory + cardiovascular response during consummatory period

Question 23

Evidence from human amygdala

Answer 23

Amygdala lesioned Participants vs healthy ones were presented abstract images paired with high media or low probability of food reward

Control
–> preference for images with high reward probability

Lesion
–> no preference displayed

THUS:

Question 24

2. Misconception

Amygdala is critical for reward processing

Answer 24

It is essential for linking objects with the current value of reward

BUT: not for stimulus-reward association per se

–> it provides a value signal, but once it is learned, the amygdala is not needed anymore (=conditional role)

Question 25

Stimulus reward associations test

Answer 25

Used to assess reward processing

1. Object reversal learning
2. Win-stay, lose-shift

Question 26

Object reversal learning

Answer 26

One stimulus is associated with reward, the other not

–> once learned the associations are switched

THUS: one needs to establish + re-establish stimulus reward association

Question 27

Win-stay, lose-shift

Answer 27

One of 2 stimuli is associated with reward in a single acquisition trial

–> ought to return to stimulus that is associated with the reward + avoid the other one on the next/subsequent trial

Question 28

How does the amygdala enhance sensory processing in the rhinal cortex ?

Answer 28

If the BLA activity shortly precede the rhinal activity, it is much more correlated

–> increased rhinal cortex transmission leads to enhanced processing + storage of emotions memories

Question 29

Inferior temporal + Perirhinal cortex

IT/PRh

Answer 29

Sensory areas

–> interaction with frontal cortex is important for the implementation of visually guided movements

Question 30

Object reversal learning depends on … ?

Answer 30

OFC + rhinal cortex

Question 31

Name the 2 routes to OFC subserve reward based decisions

Answer 31

1. IT/PRh-OFC
   - -> processes visually guided info
2. Amygdala-OFC
   - -> processes affective info