Lecture 18 Flashcards
(19 cards)
What influences the subjective value of money?
How much we already have, whether it’s a gain or loss, and how certain we are to receive it (risk).
What is expected value and how is it computed?
Expected value = reward magnitude × probability; it reflects both how good and how likely an outcome is.
Which brain areas integrate reward magnitude and probability?
vmPFC and ventral striatum (vStr).
Do expected value signals appear for abstract outcomes?
Yes, such as lives saved.
How do people behave differently for gains vs. losses under uncertainty?
People tend to be risk-averse for gains and risk-seeking for losses.
What types of cost contribute to value discounting?
Price, time (delay), and effort.
What is the role of vmPFC in discounting?
It reflects the overall subjective value after factoring in costs like delay or price.
What is delay discounting?
The process of devaluing rewards that are delayed in time.
What brain regions are involved in delay discounting?
vStr reflects future reward, LPFC tracks delay cost, vmPFC encodes the discounted value.
How does imagining a future event affect delay discounting?
Imagining a future episode reduces discounting by engaging vmPFC-MTL interaction.
What real-world traits are linked to delay and effort discounting?
Higher discounting predicts impulsivity (e.g., substance use), while lower predicts motivation.
How does vmPFC handle attribute integration?
It encodes combined value of different attributes, weighted by importance.
What does the lateral OFC encode during decision-making?
Low-level features like taste, color, or size.
How does attention affect decision-making and value integration?
LPFC can bias attention to certain features, altering attribute weighting in vmPFC.
How do people respond to risk vs. ambiguity?
They usually prefer known risks over ambiguous options.
What is the difference between exploration and exploitation?
Exploration involves trying uncertain options to learn; exploitation sticks with known good options.
What brain region supports exploration and counterfactual thinking?
Anterior LPFC.
What is the evidence accumulation model in decision-making?
It describes how we accumulate noisy evidence until we reach a decision threshold (e.g., drift diffusion model).
What factors affect evidence accumulation?
Drift rate (evidence quality), threshold (caution), starting bias, and unrelated delays (perception/action).
