operant conditioning rg 6c modified powerpoint from: aneeq ahmad -- henderson state university....
TRANSCRIPT
Operant Conditioning
RG 6c
Modified PowerPoint from: Aneeq Ahmad -- Henderson State University. Worth Publishers © 2007
Operant & Classical Conditioning
●Classical conditioning
forms associations
between stimuli (CS
and US).
●Operant conditioning
on the other hand
forms association
between behaviors
and resulting events.
E.L. Thorndike
Law of effect
●responses that produce desirable results will
be learned, or “stamped” into the organism
Yale University
Library
Found that hungry cats in a
puzzle box would work
diligently to solve the puzzle by
trial-and-error to obtain the
food reward outside the box.
Gradually, on succeeding trials,
erroneous responses were
eliminated & effective
responses were “stamped in.”
B.F. Skinner -- Operant Chamber
Using Thorndike's law of effect as a starting
point, Skinner developed the Operant chamber
or the “Skinner box” to study operant
conditioning.
From The Essentials of Conditioning and Learning,
3rd
Edition by Michael P. Domjan, 2005. Used with
permission
by Thomson Learning, Wadsworth Division
Operant Chamber
Operant chamber or Skinner box comes with a bar or key that an animal manipulates to obtain a
food or water reinforcer. It is connected to devices that record the animal’s
responses and allows the researcher to have
complete control over the animal’s environment.
Shaping
Operant conditioning procedure in which
reinforcers guide behavior closer towards target
behavior through successive approximations.
A rat shaped to sniff mines. A manatee shaped to discriminate
objects with different shapes, colors and sizes.
Khamis Ramadhan/ Panapress/ Getty
ImagesFred Bavendam/ Peter Arnold,
Inc.
Types of Reinforcers
Any event that strengthens the behavior it
follows. A heat lamp positively reinforces a
meerkat’s behavior in cold.
Reuters/
Corbis
1.Primary Reinforcer: Innately reinforcing
stimulus that usually satisfy some biological
need like food or drink.
2.Conditioned (Secondary) Reinforcer: Is a
learned reinforcer. It gets its reinforcing power
through its association with primary reinforcer. Examples…
Grades, praise, smiles of
approval and applause
Primary & Secondary Reinforcers
1.Immediate Reinforcer: A reinforcer that
occurs closely to a behavior in time. Rat gets
a food pellet for a bar press.
2.Delayed Reinforcer: A reinforcer that is
delayed in time for a certain behavior. A
paycheck that comes at the end of a week.
Immediate & Delayed Reinforcers
We may be more inclined to engage in small immediate
reinforcers (watching TV) than large delayed reinforcers
(Getting A in a course) which requires consistent study.
1.Positive Reinforcement: Increase in response by
adding/giving a positive stimulus Getting $5 for each A on your report card
Giving candy for every right answer in class
2.Negative Reinforcement: Increase in response
by removing an aversive (negative) stimulus Taking aspirin to relieve a headache
Faking an illness to avoid going to school
Using an umbrella to keep from getting wet
Positive & Negative Reinforcers
Add
Subtract
Add what?
Subtract what?
Reinforcement Schedules
1.Continuous Reinforcement: Reinforcing the
desired response each time it occurs. Needs
to be used when initial learning is taking
place
2.Partial (Intermittent) Reinforcement:
Reinforcing a response only part of the time.
Though results in slower acquisition in the
beginning, shows greater resistance to
extinction later on.
Ratio Schedules
Fixed-ratio schedule: Reinforces a response only after a specified number of responses
ex: piecework pay, reward cards (buy 10, get one free)
Variable-ratio schedule: Reinforces a response after an unpredictable number of responses. Produces more responding than any other method and is hard to extinguish because of unpredictability.
ex: gambling
Interval Schedules
Fixed-interval schedule: Reinforces a response only after a specified time has elapsed
ex: studying for an test the night before or getting paid every two weeks
Variable-interval schedule: Reinforces a response at unpredictable time intervals, produces slow steady responding
ex: pop quiz, fishing, stargazing
Schedules of Reinforcement
Let’s review…
●Reinforcer/reinforcment
●Primary reinforcer
●Secondary reinforcer
●Positive reinforcement
●Negative reinforcement
●Intermittent schedules of reinforcementoFixed-ratio
oVariable-ratio
oFixed-interval
oVariable-interval
Punishment
An aversive event that decreases the behavior
that it follows.
Give –
Take away + omission
training
Punishment
1.Punishment can result in unwanted fears.
2.Conveys no information to the organism.
3.Justifies pain to others.
4.Unwanted behaviors reappear in its absence.
5.Aggression towards the agent or aggression
seen as “ok” or “right.”
6.One unwanted behavior appears in place of
another.
Although there may be some justification for
occasional punishment (Larzelaere & Baumrind,
2002), it usually leads to negative effects.
Cognition & Operant ConditioningEvidence of cognitive processes during operant learning comes from rats during maze exploration, where they navigate it without an obvious reward.
Edward Tolman found that the rats seemed to develop cognitive maps or mental representation of the layout of the maze (environment) b/c if blocked the “normal” route, the rat found an alternate path
●the detour would be the shortest path around the barrier, even though the rat had not been reinforced for that alt. short path
●brain imaging points to the hippocampus a the structureinvolved in “drawing” the cognitive map
Latent Learning
Such cognitive maps are based on latent
learning which is learning that occurs without
reinforcement, but becomes apparent when an
incentive is given (Tolman & Honzik, 1930).
Tolman allowed rats to freely wander
the maze for several hours…when the
rats were later offered a reinforcement,
the ones who “wandered around” ran
through the maze more quickly than those
who had not been in the maze
Biological Predisposition
Biological constraints predispose organisms to learn associations that are naturally adaptive.
Breland and Breland (1961) showed that
animals drifted (instinctual drift) towards
their biologically predisposed instinctive
behaviors.
Marian Breland Bailey
Photo: Bob
Bailey