PSYC 361 MT2: OPERANT CONDITIONING (1) Operant Methods & Theories Of Rewards

Question 1

3 Key Elements in Instrumental Learning

Answer 1

1) Environment
2) Instrumental Behaviour
3) Consequence

Question 2

Instrumental Learning Influences

Answer 2

• Timing of reward delivery
• Rules of reward delivery
• Type of rewards
• Other stimuli associated with rewards

Question 3

Thorndike: The Law of Effect

Answer 3

• Devised puzzle box to study learning
• Connection formed between lever (S) & response (R) through many trials of cat pressing lever
• Learning = incremental, not insightful

Question 4

The Law of Effect- SITUATION

Answer 4

Responses that produce satisfying effect in a situation = more likely to occur again in that situation

Responses that produce discomforting effect in a situation = less likely to occur again in that situation

Question 5

The Law of Effect- STIMULUS

Answer 5

Response in presence of a stimulus followed by satisfying event, association between S & R STRENGTHENED

Response in presence of a stimulus followed by annoying event, association between S & R WEAKENED

Question 6

Behaviourism: SKINNER

Answer 6

• Studied learning from a behaviourist perspective
• Coined “Operant” = OPERAtes on the environmeNT
  (Instrumental conditioning & operant conditioning interchangeable)

Question 7

Operant Conditioning

Answer 7

Reinforcement: behaviour INCREASES when it produces an APPETITIVE stimulus

Punishment: behaviour DECREASES when it produces an AVERSIVE stimulus

Skinner: stimuli as reinforcers & punishers
- Reward vs. Reinforcer: attractive & motivational property vs behaviour facilitator

Question 8

Operant Conditioning: +/- CONTINGENCY

Answer 8

Positive: action leads to presentation of stimulus
Negative: action leads to removal of stimulus

Question 9

Schedules for Reinforcement

Answer 9

Rules for when & how frequently reinforcers are delivered

continuous reinforcement schedule (CRF): every response = reinforcer delivery

partial reinforcement schedule (PRF): ratio, interval, fixed vs variable

Question 10

Schedules for Reinforcement: PARTIAL REINFORCEMENT SCHEDULE (PRF)

Answer 10

Ratio Schedule: reinforcers delivered based on # of times response occurs

Interval Schedule: reinforcers delivered based on time elapsed after which response occurs

Fixed vs Variable:
- Fixed = # responses/time has to elapse is certain
- Variable = overall average known but #/time for each reinforcer delivery uncertain

Question 11

Fixed vs Variable: RESPONDING PATTERNS TO SCHEDULES

Answer 11

VR: steady & robust responding (leads to strongest responding typically)
FR: post-reinforcement pause & ratio run
VI: steady & stable responding
FI: fixed-interval scallop

Question 12

Extinction

Answer 12

Conditioned response diminishes due to lack of reinforcement; rate affected by previous reinforcement schedules (ie. slot machines operate on VR)
- learning process; actions no longer produce rewards
- Adaptive: saves energy by reducing unnecessary behaviour

Question 13

Primary vs Secondary Reinforcers

Answer 13

Primary: often biologically essential (food, water)

*Secondary**: stimuli previously paired with primary reinforcer becomes reinforcing in nits own right, aka Conditioned Reinforcers (lever, clicker, voucher)

Question 14

4 Different Functions of Secondary (Conditioned) Reinforcers

Answer 14

1. Reinforcing of new learning response
2. Establishing & maintaining schedules of reinforcement
3. Maintaining of behaviour during extinction
4. Mediating delays between response & delivery of reinforcement

Question 15

Timing of Reinforcer Delivery

Answer 15

Temporal Contiguity: how soon reinforcer follows response

Immediate reinforcer delivery = max learning

Delays to reinforcer delivery discounts reinforcing effect

Question 16

Theories of Rewards

Answer 16

Rewards as Reinforcers: rewards often called reinforcers because responses followed by reward strengthens association between certain environmental conditions (S) & R

Rewards as Incentives: the anticipation/expectancy of reward arouses incentive motivation

Question 17

Theories of Rewards- RESPONSE THEORIES

Answer 17

Skinner: reinforcers focuses on functional aspect; any stimulus following a response that increases probability of that response’s recurring = reinforcer

Approach has considerable practical utility, often difficult to determine what will be good reinforcer for given person in given situation

Question 18

Theories of Rewards- RESPONSE THEORIES: PREMACK’S PRINCIPLE

Answer 18

Premack’s Principle: if 2 responses are arranged in an operant conditioning procedure, the more probable response will reinforce less probable response; less probable response will not reinforce more probable response

Responses occur @ different probability; what is reinforcing is relative, not absolute— dependent on probability of responses (rats deprived of water/wheel)

Momentary Probability: probability of the behaviour at a given time in given situation; reflect “value” of behaviour, can be manipulated by deprivation of size of reward

Question 19

Theories of Rewards- MOTIVATIONAL THEORIES

Answer 19

Based on homeostatic model: drive from need, energizes behaviour to reach goal
- need —> drive —> activity —> goal —> reduced drive —> reduced activity

Drive Reduction Theory (Hull): any behavioural outcomes that reduce drive is reinforcing

Question 20

Theories of Rewards- MOTIVATIONAL THEORIES: NEED REDUCTION & DRIVE STIMULUS REDUCTION

Answer 20

(Miller, Kessen): hungry rat either drank milk/had milk directed injected into stomach during T-maze learning—> drink = better reinforce

Injecting milk more reinforcing than injecting saline solution

If only need reduction true, drinking/injecting milk should be equally reinforcing

Drinking milk reduced both drive stimulus intensity & need; injecting milk only reduced need (saline neither)

Question 21

Theories of Rewards- MOTIVATIONAL THEORIES: DRIVE REDUCTION THEORY

Answer 21

Evidence:
- milk vs saline (miller, kessen)
- pain avoidance: press bar to avoid shock
- fear reduction: escape in fear-eliciting environment

Evidence Against:
- events that do not reduce drive still reinforce
- self-stimulation of brain (olds, milner)
- monkeys work for “sensory experience”

Question 22

Are rewards necessary for learning?

Answer 22

2 assumptions that rewards act as reinforcers
1) learning is an associative process
2) role of rewards is to form &/ strengthen associations

• if learning not associative/reinforcement not necessary for learning, theories challenged

Question 23

Latent Learning

Answer 23

Hungry rats learned to run maze rewarded/not

Reward made animals run maze faster

Non-reward still completed maze

Introduction of reward improved performance of previously non-reward rats

Latent Learning: learning occurred, but not manifested until reward introduced

Question 24

Latent Extinction

Answer 24

Extinction of previously rewarded response can occur without performance of response in absence of reward
- rats learn to run down runway to goalbox for reward, if rat is 1st placed in empty goalbox & then allowed to run down runway to empty goalbox (extinction), extinguish faster
- suggesting rat is not expecting reward

Question 25

Theories of Incentive Motivation

Answer 25

Alternate view to rewards as reinforcers: the anticipation/expectancy of reward arouses incentive motivation, a drive state which prompts us to engage in activities that lead to rewards

Way in which objects & events in environment can acquire high motivational value & drive behaviour, even in absence of clear biological need

Question 26

Incentive Shifts

Answer 26

Animals respond “better” (faster, vigorously, accurately) for bigger rewards
—> do better/more motivated to perform?

Support for Motivational Hypothesis: animals learn to respond for either small/large reward & then shifted from small to large/large to small
- performance changes to appropriate levels but changes too fast to be explained by learning

Question 27

Behavioural Contrast

Answer 27

Contrast Effects: the enhancement/diminishment, relative to normal, of perception, cognition & related performance as result of immediately previous/simultaneous exposure to a stimulus of greater/lesser value in the same dimension

Question 28

Deprivation Effects

Answer 28

Incentive motivational view on deprivation; deprivation does not directly energize the behaviour, rather increases incentive motivation by making anticipated incentives more attractive/valuable
- Tomlin: only hungry animals show latent learning— for sated animals, food has no/little incentive value
- Alliesthesia (cabanac): hunger makes food a better incentive; thirst makes water a better incentive, etc. reflecting the palatability of the reward

Question 29

Summary of Operant Conditioning

Answer 29

Instrumental behaviour is goal-directed & can be modified by learning procedure

Operant method allows for studying learning in freely behaving animals

Various factors
- Each reinforcement theory can explain some, but not all instrumental learning phenomena
- Learning & performance may be differentially influenced by motivation & motivation is complicated & better theories may be needed