OPERANT
CONDITIONING
DEF: A FORM OF LEARNING IN WHICH RESPONSES
COME TO BE CONTROLLED BY THEIR CONSEQUENCES
THORNDIKE’S LAW OF EFFECT
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Edward L. Thorndike
Studied instrumental learning
This is the foundation of operant conditioning
Cat studies
LAW OF EFFECT
• DEF: if a response in the presence of a stimulus leads
to a satisfying effects, the association between the
stimulus and the response is strengthened
• The cornerstone of B.F. Skinner’s theory
SKINNER’S DEMONSTRATION
• Skinner showed that organisms tend to repeat those
responses that are followed by favorable
consequences
• Reinforcement: occurs when an event following a
response increases an organism’s tendency to
make that response
TERMINOLOGY
• Operant chamber: “Skinner Box”, a small enclosure
in which an animal can make a specific response
that is recorded while the consequences of the
response are systematically controlled
• Used to control Reinforcement contingencies: rules
that determine whether response lead to the
presentation of reinforcers
BASIC PROCESSES OF OPERANT
CONDITIONING
• Shaping: the reinforcement of closer and closer
approximations of a desired response
• Important in acquisition
• Necessary when an organism does not emit the
desired response
BASIC PROCESSES OF OPERANT
CONDITIONING
• Extinction: weakening and disappearance of a
response tendency b/c the response is no longer
followed by a reinforcer
• Resistance to extinction: when an organism
continues to make a response after delivery of the
reinforcer for it has been terminated
DISCRIMINATIVE STIMULI
• DEF: cues that influence operant behavior by
indicating the probable consequences of a
response
• Regulate operant behavior
STIMULUS
GENERALIZATION/DISCRIMINATION
• Generalization: Responding to a new stimulus as if it
were the original
• Stimulus discrimination: decrease in response to a
new stimulus that resembles the original
REINFORCEMENT
• Strengthening of a response tendency
• Defined after the fact, in terms of effect on
behavior
• Reinforcement is subjective
DELAYED REINFORCEMENT
• Favorable outcomes are more likely to strengthen a
response if the outcome follows immediately
CONDITIONED REINFORCEMENT
• Primary reinforcers: events that are inherently
reinforcing b/c they satisfy biological needs
• Secondary (conditioned) reinforcers: events that
acquire reinforcing qualities by being associated
w/primary reinforcers
INTERMITTENT REINFORCEMENT:
EFFECTS OF BASIC SCHEDULES
• Schedule of reinforcement: determines which
occurrences of a specific response result in the
presentation of a reinforcer
INTERMITTENT REINFORCEMENT
• Continuous reinforcement: occurs when every
instance of a designated response is reinforced
• Intermittent, partial, reinforcement: occurs when a
designated response is reinforced only some of the
time
• Intermittent makes a response more resistant to
extinction
• There are 4 types of intermittent reinforcement…
FIXED-RATIO (FR) SCHEDULE
• Ratio schedules require the organism to make a
response a certain amount of times to gain a
reinforcer
• FR Schedule: the reinforcer is given after a fixed
number of nonreinforced responses
VARIABLE-RATIO (VR) SCHEDULE
• The reinforcer is given after a variable number of
nonreinforced responses
FIXED-INTERVAL (FI) SCHEDULE
• Interval schedules require a time period to pass
btwn presentation of reinforcers
• FI Schedule: the reinforcer is given for the 1st
response that occurs after a fixed time interval has
elapsed
VARIABLE-INTERVAL (VI) SCHEDULE
• The reinforcer is given for the 1st response after a
variable time interval has elapsed
• Interval length depends on a predetermined avg.
RATIO VS. INTERVAL
• Ratio schedules produce more rapid responding
• Variable schedules tend to generate steadier
response rates and greater resistance to extinction
CONCURRENT SCHEDULES OF
REINFORCEMENT
• Concurrent schedules of reinforcement: consist of 2
or more reinforcement schedules that operate
simultaneously and independently, each for a
different response
MATCHING LAW
• States that under concurrent schedules of
reinforcement, organisms’ relative rate of
responding to each alternative tends to match
each alternative’s relative rate of reinforcement
• Quality of reinforcement earned also effects
response rate
• Assumes organisms are working to maximize their
overall reinforcement
MATCHING AND FORAGING
• Optimal foraging theory: food seeking behaviors of
many animals maximize the nutrition gained in
relation to the energy expended to locate, secure,
and consume various foods
POSITIVE REINFORCEMENT
• Occurs when a response is strengthened b/c it is
followed by the presentation of a rewarding
stimulus
NEGATIVE REINFORCEMENT
• Occurs when a response is strengthened b/c it is
followed by the removal of an aversive stimulus
• Don’t be confused by word negative
• Many everyday behaviors effected by negative
reinforcement
ESCAPE LEARNING
• Def: an organism acquires a response that
decreases or ends some aversive stimulation
• Shuttle box
AVOIDANCE LEARNING
• DEF: an organism acquires a response that prevents
some aversive stimulation from occurring
• Avoidance learning responses are very resistant to
extinction
TWO-PROCESS THEORY OF AVOIDANCE
• Avoidance begins b/c classical conditioning
creates a conditioned fear
• Avoidance is maintained by operant conditioning
• Avoidance response is strengthened through
negative reinforcement
PUNISHMENT: CONSEQUENCES THAT
WEAKEN RESPONSES
• Punishment occurs when an event following a
response weakens the tendency to make that
response
• NOT NEGATIVE REINFORCEMENT!!!
PUNISHMENT
Can have side effects:
General suppression of behavioral activity
Trigger strong emotional responses
Physical punishment often leads to aggressive
behavior
• More effective to reinforce desirable behavior than
punish undesirable behavior
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