L19 & 20 - Neurobiology of Decision Making Flashcards
How do decisions have a link between memory and future actions?
Experience retrieved from memory - decision - future actions
Influenced by past decisions
Prediction about next experience
What is the prediction choice outcome loop?
Goal - prediction - decision - action - outcome - monitoring: calculate prediction error - update memory and go back to the start
What are the general features of decision making?
Avoid harm
Maximise reward
Minimise time, effort and missed opportunities
Make predictions of possible decision outcomes to optimise our decision making process
Rely on memory to make predictions
What are the factors we consider before making a decision?
Difficulty of the action - effort
Probability of success or failure
How valuable is the possible reward
Missed opportunity - when you choose one thing you are rejecting something else
What are the biases in decision making?
Stick with default e.g. choosing the same meal at a restaurant
Choose gains over gambles
Choose gamble over losses
Temporal discounting - choosing immediate rewards over future rewards unless benefits are explicit
What are the different levels of decision-making?
Simple perceptual decisions
More complex decisions
What is the perceptual decision task?
Random-dot motion task
- monkey maintains fixation
- random dots are presented
- certain percentage of dots moves coherently, some randomly
- when monkey detects main motion direction - eye movement to corresponding target
Neurons tuned to encode relevant features
Evidence accumulation over time
What are the 3 stages of perceptual decision making?
- Detection of sensory evidence - what are the alternatives that can be detected
- Integration of evidence over time - evidence is noisy
- Checking if threshold has been reached - if so, elicit action, if not, accumulate more evidence
Where does evidence accumulation take place?
Brain areas responsible for encoding the relevant feature
Parietal and dorsal prefrontal cortex
Recent evidence: sensorimotor areas representing possible actions, accumulate evidence as well
Adapt and react
What is the hypothesis for mental maps in decision making?
Decision making processes rely on internal models of the current task
Experiences need to be organised in internal models or mental maps
e.g. queues are longer on Fridays on route A
What are the historical roots of mental maps?
Edward Tolman: rats in a maze
Rats have to find their way out of the maze
Quickly learned to take a detour when it became available
Encoded transitive relations to build mental maps
What are mental maps in decision making?
Principles can be transferred to non-spatial tasks e.g. coding an experiment in psychopy
Might find something complicated at first but then find a shortcut later with more experience
Problems can be described as a series of decisions and mental maps guide you through
What is the hippocampus’ role in mental maps and decision making?
Retrieval of long term memory content: associated with the hippocampus
What is the study showing upcoming strategy switch in decision making?
Task:
- identify arrangement of pattern within the white square
- upper left or lower right corner = right button press
- upper right or lower left corner = left button press
No instruction regarding colours
The colours could be used to determine response as well after association had been learned - short cut
What were the results of the study showing upcoming shift in strategy in decision making?
Areas in medial frontal cortex representing colours in this task
From activity in the MFC: group membership could be derived even before strategy shift happened
Some aspects of decision making are represented in MFC
MFC activity seems to be linked to memory formation in DM tasks
Activity in MFC predicts a shift in strategy
