Download PSY100Learning

Learning
Prof. Tom Alloway
Definition of Learning



Change in behavior
Due to experience relevant to what is being learned
Relatively durable
 Conditioning
 Learning associations
Operant Conditioning

B.F. Skinner (1953) – principle of reinforcement
 Operant chamber
 Emission of response
 Reinforcement contingencies
 Cumulative recorder
Operant Chamber
Basic Processes in Operant Conditioning






Acquisition
Shaping
Extinction
Stimulus Control
Generalization
Discrimination
Reinforcement: Consequences that Strengthen Responses



Delayed Reinforcement
 Longer delay, slower conditioning
Primary Reinforcers
 Satisfy biological needs
Secondary Reinforcers
 Conditioned reinforcement
Intermittent Reinforcement: Effects of Basic Schedules

Continuous reinforcement
 Intermittent (partial) reinforcement
 Ratio schedules
 Fixed
 Variable
 Interval schedules
 Fixed
 Variable
Concurrent Schedules of Reinforcement
and the Study of Choice

Concurrent Schedules - Two responses reinforced on independent
schedules. Concurrent VI-VI is the most studied.
 Matching law
The ratio of the response rates on two manipulanda is equal to the
ratio of their reinforcement rates.
RA rA

RB rB
The relative rate of responding on a manipulandum is equal to its
relative rate of reinforcement.
RA
rA

RA  RB rA  rB

Optimal foraging theory - Animals behave in a way that maximizes rate
of intake of nutrition in relation to energy expended.
Positive and Negative Reinforcement

Increasing a response:
 Positive reinforcement = response followed by rewarding
stimulus
 Negative reinforcement = response followed by removal of an
aversive stimulus
 Escape learning
 Avoidance learning
 Decreasing a response:
 Punishment
 Problems with punishment
Classical conditioning

Pavlov’s Demonstration
 Terminology
 Unconditioned Stimulus (UCS)
 Conditioned Stimulus (CS)
 Unconditioned Response (UCR)
 Conditioned Response (CR)
Classical Conditioning: Terminology Continued




Eliciting a response = drawing forth
Trial = pairing of CS and UCS (CS generally precedes UCS)
Acquisition = forming a new conditioned response
Stimulus contiguity = occurring together in time and space
Processes in Classical Conditioning






Extinction
Spontaneous Recovery
Stimulus Generalization
Stimulus Discrimination
Higher-order conditioning
Sensory Preconditioning
Conditioned Emotional Response (CER)
(Fear Conditioning in the Lab)







CER is most commonly studied form of classical
conditioning.
First, a rat is trained to bar press in an operant chamber.
Then, the rat is trained onto a medium-sized variableratio schedule to produce rapid, steady responding.
Electric shock can be used a UCS that will temporarily
suppress bar pressing.
A light or tone can be used as a CS that initially has no
effect on bar pressing rate.
If a CS precedes the shock several times, it acquires the
capacity to suppress bar pressing. The CS’s acquired
response suppression is a CR.
The suppression ratio is measure used to determine
how much the CS suppresses bar pressing.
Suppression Ratio



Suppression ratio will be 0.5 if the CS has no effect on bar
pressing rate.
A suppression ratio less than 0.5 indicates that the animal
is responding more slowly during of the CS than in its
absence.
(A suppression ratio greater than 0.5 would indicate that the
animal is responding faster during the CS. That shouldn’t
happen (except by chance) during CER conditioning.
Higher Order Conditioning
Sensory Preconditioning



Stage 1 - CS1 – CS2 (Light – Tone)
Stage 2 - CS2 – UCS (Tone – Shock)
Stage 3 - Test CS1
Shuttle-Box Avoidance Learning
(Classical and Operant Conditioning Combined)
New Directions in the Study of Conditioning


Biological Constraints on Conditioning
 Instinctive Drift
 Conditioned Taste Aversion
 Evolutionary Perspective
Cognitive Influences on Conditioning
 Signal relations
 Response-outcome relations
Conditioned Taste Aversion
Observational Learning: Basic Processes


Observational learning or vicarious conditioning
 Extending the reach of conditioning processes
Albert Bandura
 Example: Punishment and aggressive behavior