PSYC 335 - Decision Neuroscience

Lectures 5-7

What happened with Damasio’s patient, EVR?

High IQ and high functioning patient of Damasio, developed a brain tumour on frontal lobe, from oncology POV was a success (passed those neuropsych tests), but ended up making many risky decisions and life falls apart

What part of the brain when damaged led to making choices with immediate gratification but bad long term?

Ventromedial Prefrontal cortex

What was the Iowa Gambling task?

4 decks, 2 risky (high rewards on cards but even harsher losses that led to net losses) and 2 normal (lower rewards and less harsh losses that led to net gains)

What did the Iowa Gambling task show

EVR and EVR-like patients preferred the bad decks, and healthy control group preferred the normal deck

How was skin conductance used in the Iowa Gambling Task in terms of punishments and rewards?

Healthy group and ventromedial damage group had more activity for punishments and rewards, amygdala damage had no reaction

How was skin conductance used in the Iowa Gambling Task for taking a card

Healthy groups used knowledge of past results, and had big reactions before taking a card where ventromedial damage groups and amygdala damage groups had no reaction

How did people with gambling problems perform on the Iowa Gambling Task?

Tend to take the riskier deck despite no signs of neurological damage

What is dopamine?

A localized neurotransmitter that predicts reward

What “produces” dopamine?

Substania nigra and ventral tegmental area

What are the pathways for dopamine

Nigro-striatal pathway (parkinsons degenerates this path), meso-limbic pathway (associated with reward)

Where does the meso-limbic pathway go?

From meso-limbic pathway to nucleus accumebens

What was the Schultz study

Showed a monkey a squiggle on a screen, then gave them grape juice (unconditioned stimulus) after, in a pavlov’s dog like manner

What did the Schultz study show

At first, the dopamine fired after grape juice was delivered, but after a while, dopamine was released after the squiggle was shown, showing that dopamine is used to predict reward

What does an fMRI do?

Leverages the magnetic properties of oxygenated and deoxygenated blood to see brain activity

How can an fMRI be used to measure the reward system and what are the limitations?

Can use to see activity in ventral striatum, but we cannot assume activity there = dopamine as many NT’s work there

What were Dar Meshi’s studies

Simplified social media, placed a photo of yourself with either a positive or negative adjective under it

What did Dar Meshi’s studies show

Ventral striatum responded to positive adjectives

What were Shermans studies?

Had participants own photos, normal photos, and risky photos, photoshopped the number of likes on the photo, ventral striatum only reacted to the participants own photos based on number of likes