Neurobiology of decision making Flashcards
1
Q
decisions in everyday life
A
- Important part of life
- Deciding between options
- Diff choices of same thing (e.g. choosing between brands)
- Some bigger - change course of life
2
Q
mem –> decisions –> future actions
fellows (2018)
A
- Decisions based on experiences from mem - base on what you have experienced in the past, what is easier
- Make predictions about what experiences are going to be - predict consequences of decisions (whether it will be very similar or very diff)
3
Q
prediction-choice-outcome loop
fellows (2018)
A
- goal
- prediction of outcome
- decision & appropriate actions
- observe action outcome
- outcome subjected to internal monitoring processes
- prediction error used to update mem
4
Q
general features of decision making
A
- avoid harm
- mimise: costs of time, effort, missed opportunities
- maximise reward
5
Q
factors to consider before making a decision
A
- Difficulty of action
- Probability of success and failure
- How valuable is the possible reward at this moment (context)
- Missed opportunities
6
Q
biases in DM
A
- Stick with default - choosing what you know
- Choosing certain gains over gambles
- Choosing gambles over certain losses
- Temporal discounting: choosing immediate rewards over future rewards unless benefits are made explicit
7
Q
different levels of DM
A
- simple perceptual decisions
- more complex decision
8
Q
random-dot motion task
perceptual decision task, hanks & summerfield (2017)
A
- Monkey maintains fixation
- Random dots presented
- Certain % of dots moves coherently, other dots move randomly
- More randomly moving = harder
- When monkey detects main motion direction, move eye to main direction of moving dots
- Noisy sensory signal converted into discrete motor act
9
Q
accumulating ev in perceptual decisions
A
- Neurons tuned to encode movements to right, some encode movements to right
- Motion detectors fire whenever detect movement in certain direction
- Accumulated until one of these reaches decision threshold
10
Q
3 stges of perceptual DM
A
- Detection of sensory evidence: what are the alternatives that can be detected
- Integration of ev over time –> because evidence is noisy
- Checking if threshold has been reached
* –> if so, elicit appropriate action
* –> if not, accumulate more ev
11
Q
where does ev accumulation take place
simple perceptual decisions
A
- Brain areas responsible for encoding the relevant feature e.g. area MT/V5 with motion in DM
- Parietal & dorsal prefrontal cortex
- Recent ev: sensorimotor areas representing possible actions, accumulate ev as well
12
Q
homogenous model of ev accumulation
A
all relevant neurons active at same time
13
Q
models of ev accumulation
A
- homogenous
- heterogenous
14
Q
heterogenous model of ev accumulation
A
- Collectively encoded
- Early responding neurons active quickly & pass on activity to other neurons
- wave of activity in the network
- Accumulated ev in network reflects when detection threshold will be reached
- mem for accumulated ev can both be flexible & durable
15
Q
mental maps in DM
A
- Decision making processes rely on internal models of the current task
- Experiences need to be organised in internal models or mental maps
- Internal model helps us to predict the diff outcomes of the available options based on our experiences
16
Q
mental maps in DM historically
Tolman’s rat spatial maze
A
- 2 points (A & B) spatially close but barrier between
- never experienced going straight from A –> B
- build mental map
- barrier removed: quicker route, rats quickly adapt