Chapter 6 - Schedules of Reinforcement and Choice Behaviour

Question 1

What is a schedule of reinforcement?

Answer 1

It is the rule that determines how and when a response will be reinforced

Question 2

What are the two types of reinforcement rates?

Answer 2

1. continuous reinforcement

2. partial reinforcement

Question 3

What is continuous reinforcement?

Answer 3

Reinforcing every correct response

• most efficient way to condition a new response
• rare in real life

Question 4

What is partial reinforcement?

Answer 4

Reinforcing some, but not all responses

- more effective at maintaining or increasing the rate of response (and produces long lasting responses)

Question 5

What is the consequence of having different schedules?

Answer 5

There are distinct rates and patterns of responses with varying degrees of resistance to extinction

Question 6

What are the two basic types of partial reinforcement schedules?

Answer 6

1. ratio

2. interval

Question 7

What do ratio types require?

Answer 7

A certain number of responses to be made before one is reinforced

Question 8

What do interval types require?

Answer 8

A certain amount of time to elapse before a reinforcer is given

Question 9

What are the two basic categories within ratio and interval partial reinforcement schedules?

Answer 9

1. fixed

2. variable

Question 10

Describe fixed ratio (FR) schedules

Answer 10

FR schedules

• reinforcement is given if the subject completes a pre-set number of responses (ex. FR5 = after 5 responses, the subject is rewarded)
• continuous reinforcement (CRF) is the same as FR1

Question 11

What do we observe with fixed ratio schedules?

Answer 11

1. ratio run: when the subject exhibits the same response again and again - shows that learning has occurres
2. post-reinforcement pause: taking a break in performing after reward has been given
3. ratio strain: a pause during the ratio run, following a sudden, significant increase in ratio requirement (they stop performing because of an increase in requirement)

Question 12

Describe variable ratio (VR) schedules

Answer 12

• the number of responses required to get each reinforcer is not fixed (it is random around a particular number - usually the average)
• numerical value of the ratio indicates the average number of responses required per reinforcer (ex. VR7 means that on average, 7 responses are required before a reinforcer is introduced)
• the reinforcer is less predictable, therefore there is less likelihood of pausing between responses (due to the fact that the very next response could be reinforced)

Question 13

When are interval schedules reinforced?

Answer 13

Only if they occur after a certain amount of time has passed

- time is the factor, but a response is still required to obtain a reinforcer

Question 14

Describe a fixed interval (FI) schedule?

Answer 14

• a response is only reinforced if a constant or fixed amount of time has elapsed from the previous delivery of a reinforcer (ex. FI5 = five minutes have to elapse)

Question 15

What is a fixed interval scallop?

Answer 15

Time towards the end of the interval will increase the rate of responding
- more responses closer to the time and fewer immediately after

Question 16

Describe a variable interval (VI) schedule?

Answer 16

• a response is reinforced only if it occurs more than a variable amount of time after the delivery of an earlier reinforcer
• because VI are less predictable, just like VR, there is a steady rate of response with little break in between

Question 17

Which two reinforcement schedules have the strongest response rate?

Answer 17

1. Fixed ratio
2. variable ratio
   - the organism learns that it is causing the reward with its behaviour

Question 18

What is the distinguishing characteristic of a fixed interval schedule?

Answer 18

The scallops

Question 19

Which schedule produces the highest rate of responding, and is the most resistant to extinction?

Answer 19

variable ratio schedules, because the organism doesn’t know when the response will be reinforced

Question 20

What are the similarities between ratio and interval schedules?

Answer 20

• in both FR and FI schedules there is a typical pause after each reinforcer, and an increased rate of response just before the delivery of the next reinforcer
• in both VR and VI schedules the response rate is steady without predictable pauses

Question 21

What is the difference between ratio and interval schedules?

Answer 21

Different rate of response even when reinforcement frequency is similar

Question 22

Why would different schedules with similar rates of reinforcement produce different rates of behaviour?

Answer 22

1. reinforcement of inter-response times (IRT):
   - the faster you respond, the more likely you are to receive reinforcement (probabilistic)
   - variable ratio schedules reinforce shorter IRTs
   - interval schedules favour long IRTs
2. feedback function:
   - higher responding is reinforced more (only in ratio schedules)

Question 23

Define choice behaviour

Answer 23

The voluntary act of selecting or separating from two or more things that which is preferred

Question 24

What factors are our everyday choices influenced by?

Answer 24

1. reinforcer: quality and quantity
2. behaviour: type of response, schedule of reinforcement
3. available alternatives
4. delay in reinforcement

Question 25

What is a concurrent schedule of reinforcement?

Answer 25

2 schedules of reinforcement are in effect at the same time

• the subject is free to switch between responses
• allows for continuous measurement of choice because the organism is free to switch between options at any time

Question 26

Describe Hernstein’s Matching Law

Answer 26

• can only be used for prediction of VI schedules only
• the relative rate of responding is matched to the relative rate of reinforcement
• accurate in predicting generalized rates of reinforcement
• takes into consideration all possible outcomes

Question 27

What is the formula for Hernstein’s Matching Law?

Answer 27

BL/BL+BR = rL/rL+rR

or

BL/Br = rL/rR

• the rate of reinforcement from option A (ex. 480/20 = 24)
• the rate of reinforcement from option B (ex. 480/60 = 8)
• add these two (ex. 32)
• divide rate of reinforcement of option A (24) by the total number of reinforcers possible (32) = 0.75
• do same for option B = 8/32 = 0.25
• answers should be proportions

Question 28

What is the implication of Hernstein’s Matching Law?

Answer 28

Rate of a particular response does not depend on the rate of reinforcement of that response alone

• an operant response must compete with all other behaviours for an individual’s time
• therefore, it is impossible to predict how a reinforcer will affect a behaviour without taking context into account

Question 29

What are the theories of choice behaviour?

Answer 29

maximization: organisms distribute their actions among response alternatives in order to maximize the amount of reinforcers possible in that situation
1. molecular maximizing: the choice is made according to the option that is most likely to be reinforced immediately
2. molar maximizing: the choice is made so that the highest number of reinforcers are collected in the long run (maximizing over time)

Question 30

What is a concurrent-chain schedule of reinforcement?

Answer 30

choosing one option makes the other one unavailable

• two stages:
  1. choice link (the choice)
  2. terminal link (decided by the choice link)

Question 31

Define self-control

Answer 31

Choosing a large delayed reward over an immediate small reward
- more difficult to choose a long term reward over a short term reward because of the delay

Question 32

With a direct choice, what is an animal likely to choose?

Answer 32

An immediate and small reward

Question 33

With a concurrent-chain procedure, what is an animal more likely to choose?

Answer 33

A delayed large reward

Question 34

What is the value discounting function?

Answer 34

• tries to anticipate what the decision will be
• value of the reinforcer (V) is directly related to reward magnitude (M) and inversely related to reward delay (D)
• k is the discounting rate parameter that indicates how rapidly reward value declines as a function of delay
• when the value of the small reward decreases beyond the wait time, you would be more likely to wait for the large reward

Question 35

What is the formula of the value discounting function?

Answer 35

V = M/(1+kD)

Question 36

How does self-control look for people who are addicted to heroin?

Answer 36

• they show steeper value discounting functions

- they are more impulsive and would take the immediate small reward over a delayed large reward

Question 37

How can delay discounting and impulsivity affect daily life?

Answer 37

• slower reward discounting: associated with higher grades
• faster reward discounting: associated with unsafe sex
• slower delay discounting with age (because we are less impulsive as we grow up)
• • all depend on k factor **

Question 38

How can we train someone to have more self-control?

Answer 38

1. training with delayed reinforcement increases likelihood of choosing a larger delayed reward in the future
2. pre-commitment: make the decision to choose a larger delayed alternative in advance in a manner that is difficult or impossible to change later on

Question 39

What 5 steps can we take to modify our behaviour?

Answer 39

1. identify the target behaviour
2. gather and record baseline data
3. plan your behaviour modification program
4. choose your reinforcers
5. set the reinforcement conditions and begin recording your progress