Lecture 16 (the reward system) Flashcards
Where do they place the targets in the brain in Deep Brain Stimulation (DBS)?
Nucleus accumbens and cingulate gyrus.
When is DBS used?
in people with major non-treatable depression.
Fictive prediction errors?
rewards that might have been.
Explain the reward prediction hypothesis
They have found that it seems that dopamine fire to the expectation of reward (the experiment had a red box and when that was shown, the rat would get some juice. This means red box equals juice). But when the red box wasn’t followed by juice, the dopamine did fire and great an action potential at first but not later, when they had learned that the red box now didn’t equal juice/reward.
Which two systems are the brain divided into according to the dual-mode system theory?
System 1 (fast):
• The old brain: limbic system, reward system, fight and flight
• Unconscious/unaware processes
• Driven by threats, risk and reward.
System 2 (slow):
• The new brain: prefrontal cortex and parietal cortex
• Rest and plan
• Conscious/aware processes
• Decisions are based on facts!
Temporal discounting and dual-mode system theory
people are given a choice to either choose a smaller immediate reward or to choose a larger delayed reward. When people choose the smaller immediate reward, there are higher activation in the emotional system (system 1). When they choose the larger delayed reward, we see less activity in the emotional system and more in the frontal system (system 2).
What is hyperscanning?
scan all brains during a social interaction. It is a method by which multiple subjects, each in a separate MRI scanner, can interact with one another while their brains are simultaneously scanned.
What is the trust game?
there are an investor and a trustee. The investor gets 20 dollars. The investor has to send some money to the trustee – whatever he sends, the trustee will get it times three. It loops around ten times. They get to go home with the money they end up with.
Which kind of psychiatric patient group have a hard time with the trust game?
BPD patients because that have an absent of trust.
What is processed in the OFC/vmPFC?
Reward experience/outcome
What do OFC receive information from?
OFC receives inputs from nearly all sensory modalities. This means that OFC can put together all the information from the sensory signals and potentially attach value to it (make a decision).
What is the Iowa Gambling Task?
used to see the participants decision making skills.
o They have to choose the card deck which have the best outcome.
o They start off with exploratory behavior.
o They have to find the decks with less average loss and less gain per time instead of the card decks with higher gain but also higher risk.
Why do people with ventromedial prefrontal lesions have a hard time with Iowa Gambling Task?
People with ventromedial prefrontal lesions will never learn by the feedback (altså de lærer ikke af, hvilke kort, der er de bedste at tage, fordi de har læsioner i det område, der handler om reward experience).
Expected utility?
can be measured as the amount of benefit of the outcome and the probability of that outcome occuring.
Where is reward expectation processed?
Striatum
