Cog & Bio Foraging

Question 1

What is foraging?

Answer 1

At its core, it is the act of searching for resources

Question 2

What is pray selection (accept-reject decision)?

Answer 2

Pursue or not after encountering prey item

Question 3

What is patch leaving (stay-switch decision)?

Answer 3

Stay in a patch or travel to new patch

Question 4

What is optimisation problems?

Answer 4

Subjects must maximise a reward in relation to a negative variable (such as time, effort, expended)

Question 5

What are foreground options?

Answer 5

Immediate, directly available

Question 6

What are background options?

Answer 6

Potential opportunities

Question 7

What normally arises out of a formal theory?

Answer 7

A normative solution (e.g optimal solution) usually arises out of a formal theory

Question 8

Gain = ?

Answer 8

Food intake

Question 9

What does the marginal value theorem predict?

Answer 9

Predicts longer time in foraging at a patch when travel time is long vs short

Question 10

What 5 assumptions does the marginal value theorem make?

Answer 10

1. Each patch type is recognised instantaneously
2. Travel time between patches is known
3. Gain curve is smooth, continuous & decelerating
4. Travel time between & searching within a patch have equal energy costs
5. Individual is assumed to control when it leaves the patch

Nonetheless, it describes well a large range of behaviours - animals, plants & human hunger gathers

Question 11

Example from animal ecology:

Answer 11

• starlings flies to patch to find food for family, once at patch can get as many worms as it wants, but each extra work requires more time at patch

Question 12

Small n :

Answer 12

Small account of time at each patch
But
Little food at each return trip
Exert calories flying and calories of the nest clambering for food

Question 13

What is greedy method?

Answer 13

A simple strategy where the agent selects the option with the highest estimated reward

Question 14

Patch leaving (humans) - global fluctuations :

Answer 14

Subjects harvest to lower thresholds in lower quality (long travel time) environments (consists with MVT)

Question 15

Opportunity cost =

Answer 15

Harvest time x reward _ rate

Question 16

The dorsal anterior cingulate cortex is thought to be related to what?

Answer 16

Calculating background estimates

Question 17

Dorsal anterior cingulate cortex - reward outcomes, effort and dysfunction

Answer 17

dACC related to reward outcome monitoring and behavioural adjustment

dACC related to effort based decisions

dACC dysfunction linked with maladaptive patterns of cognition including depression, addiction, OCD

Question 18

What part is brain is foreground option related to?

Answer 18

Ventral medial prefrontal cortex

Question 19

What did monkeys behaviour closely match?

Answer 19

Closely matches the predictions of the MVT

Question 20

Patch leaving (neurophysiology)

Answer 20

dACC neurons responded each time monkey made a choice - responses increased with time spent in the current patch

Neurons in the dACC increased their firing rates when patches depleted, to the point where monkeys abandoned the patch

Encodes the relative value of leaving a patch

Question 21

What does a monoamine neurotransmitter carry?

Answer 21

Carries chemical signals from one neuron (nerve cell) to the next target

Question 22

What are the dopamine pathways?

Answer 22

Mesocortical pathway
Mesolimbic pathway
Nigrostriatal pathway

Question 23

What is phasic?

Answer 23

Dopamine neurons fire extra spikes in brief episodes referred to as ‘phasic’ or ‘burst’ firing - important for fast learning - signals ‘surprise’ (prediction errors)

Question 24

What is tonic?

Answer 24

Dopamine neurons of the midbrain usually fire spontaneously at low rates, a firing mode that is called tonic - purported role in representing background reward rates of the type used in foraging decisions

Question 25

What did the tonic dopamine and patch foraging study show?

Answer 25

Short were more pessimistic about the environment and thought it was less rewarding

Question 26

What is cabergoline and what does it do?

Answer 26

A dopamine agonist (increases tonic dopamine levels) It alters use of background reward info to guide latch leaving (quicker to leave patches)

Question 27

What does prey selection depend on?

Answer 27

The environment The environment changes whether we see an option as rewarding or not

Question 28

What does a rich environment show on a graph

Answer 28

Goes up from starting point in a slight curve - can be very selective

Question 29

What does a poor environment look like on a graph?

Answer 29

Will go lower than starting point - will be less selective

Question 30

Pray selection - manipulating the environment findings

Answer 30

Participants are less selective in poor environments, implies that participants learn the value of their environment

Question 31

What does evidence of block wise learning suggest?

Answer 31

It’s harder to adjust from rich to poor environments - suggest that asymmetric reaction to positive and negative updates

Question 32

What are the 2 options in prey selection?

Answer 32

Reward - points obtained Opportunity cost

Question 33

Opportunity cost in a rich a poor environment

Answer 33

Rich environment - even a few seconds may be a waste and you won’t chase Poor environment - chase is everything regardless of time

Question 34

Prey selection - updating beliefs :

Answer 34

Asymmetry arises from positive learning exceeding negative

Question 35

When are people more responsive?

Answer 35

When info is better than they thought than info that was worse than they thought

Question 36

What happens to order effect in a study on prey selection?

Answer 36

Order effect disappears with sufficient exposure to info

Question 37

What does threat do?

Answer 37

Makes us more sensitive to negative information

Question 38

Perspective meaning?

Answer 38

Systems, like stress, are good for monitoring, adjusting to overall environment characteristics

Question 39

When do participants learn more from information?

Answer 39

When the stress response is higher than when it is low

Question 40

Stress response =

Answer 40

=> lower appraisal of environmental quality, pessimistic about reward rate => over exploit environment

Question 41

Depression - a decision theoretic analysis - basic idea?

Answer 41

Basic idea - specific symptoms of orders like depression are consistent with low estimation of the environments reward rate

Question 42

What is addiction marked by?

Answer 42

Marked by a tendency to exploit sources of reward despite diminishing returns Tested people with and without opioid use disorder on the patch-foraging task - more pessimistic about the environment