Drive

Reinforcement

Incentive

Basic concepts

Classical conditioning in “TV experiment” [Video]

http://www.youtube.com/watch?v=lnL4fjMzsSU

Thorndike’s classic experiment [Video]

https://www.youtube.com/watch?v=fanm--WyQJo

Duration: 2:22 min

Types of reinforcement

Appetitive Aversive

Hedonic value

Response

contingency

Positive

Negative

Lever → Food

Lever

Positive reinforcement Punishment

Negative reinforcementOmission training

Lever → Shock

Lever

Lever Shuttling

Lever → No food Shuttle → No shock

Complexity of instrumental behavior [Video]

Shaping instrumental behavior

Lever

Signals to us

that food has

been delivered

Food pelletsSkinner box

Rat pressing a lever

[Video]

Resistance to change [Video]

Intrinsic motivation

•Latent learning: reinforcement brings knowledge about the situation to the

behavioral level.

0

2

4

6

8

10

12

0 2 4 6 8 10 12 14 16 18

Trials

Avera

ge E

rrors

No Food

Delayed Food

Regular Food

Start

Goal

Doors

Curtains

Reinforcing drawing in children

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Group Pretest Training Posttest

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Verbal “That picture is very nice”

Money “You have just earned 5 cents”

Award Time drawing “I’ll give you a good player award” Time drawing

Control I E present, but ignoring child

Control II E paid attention, but did not approve

Control III No treatment

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Anderson et al., J Pers Soc Psychol, 1976, 34, 915-922.

•Rewarding a difficult task produces classical conditioning involving the pairing

of effort (the CS) with the reward (the US).

•Such pairings reduce the effort's aversiveness (counterconditioning).

•When a difficult task is followed by reward, the effort becomes less aversive,

increasing the amount of effort the individual subsequently chooses to spend

performing this and other difficult tasks.

•Eisenberger & Rhoades (2001) showed that rewarding an activity defined as

creative with verbal praise and 5 cents generates greater levels of creativity

than just verbal praise and a no reward condition in preadolescent children.

•Furthermore, rewarding creativity in one task (describe a way in which a regular

object can be used in a nonconventional way; e.g., use a book to hold a door

open) generalizes to a second creative activity (find up to 16 titles for this story).

Learned industriousness

Reinforcers as commodities: behavior economics

• In lab experiments, animals obtain reinforcers in a

small enclosure.

• An animal receives payment (food) for a given

amount of work (lever pressing).

• Does behavior adjusts to an increased price

(increased response requirement)?

• As the ratio of responses/reinforcers increases, the

price of the reinforcer also increases.

• The relationship between price and work is

described by a demand curve.

• Elastic demand: when work decreases as the price

increases (luxury items).

• Inelastic demand: when work remains constant as

price increases (milk, bread).

Inelastic demand:

Milk, bread

Elastic demand:

TV set, watch

Reinforcers as commodities: behavior economics

• Lab procedures to study reinforcement: closed economies.

• Real live: open economies.

• Are the principles of reinforcement the same in closed vs. open economies?

• Experiments: two responses, two rewards, changing requirements for one reward may or not affect

responding for that reward.

• Understanding drug addiction in economic terms.

Bentzley et al., PNAS, 2014, 111, 11822-11827.

Demand function for cocaine

A: Oxytocin

reduces cocaine

demand

B: Oxytocin

increases demand

elasticity

http://www.ted.com/talks/lang/eng/laurie_santos.html

Duration: 19:24 min

Behavior economics

• Monkeys learn to use tokens (a type of currency) in exchange for goods.

• This allows researchers to create an “economic market.”

• Monkeys are sensitive to the amount of food they can “buy” with their tokens.

• No evidence of savings, but monkeys spontaneous stole tokens from others.

• Risky vs. safe choices under the same conditions.

• Safety is preferred when gains are likely.

• Risky decisions are preferred when losses are likely.

• Two biases:

• Relativity (difficulty of thinking in absolute terms).

• Loss aversion (we really hate it when we have to lose money).

• Monkeys and humans display similar mental biases.

Behavior economics: video summary