Post on 30-Oct-2014
description
transcript
Myers’ EXPLORING PSYCHOLOGY (5th Ed)
Chapter 7
Learning
James A. McCubbin, PhDClemson University
Worth Publishers
Learning Learning
relatively permanent change in an organism’s behavior due to experience
Associative Learning learning that two events occur together
two stimulia response and its consequences
Classical or Pavlovian Conditioning
We learn to associate two stimuli
Two related events:
Lightning
Stimulus 1
Thunder
Stimulus 2
Result after repetition
We see lightning
Stimulus
We wince anticipatingthunder
Response
Operant Conditioning
We learn to associate a response and its consequence
Response: Pushingvending machine button
Consequence:Receivinga candy bar
Learning
Behaviorism Promoted by John B. Watson View that psychology…
should be an objective sciencestudies behavior without reference to mental processes
Classical or Pavlovian Conditioning
Ivan Pavlov 1849-1936 Russian physician/
neurophysiologist Nobel Prize in 1904 studied digestive
secretions
Classical or Pavlovian Conditioning
Classical Conditioning organism comes to associate two stimuli
lightning and thundertone and food
begins with a reflex a neutral stimulus is paired with a
stimulus that evokes the reflex neutral stimulus eventually comes to
evoke the reflex
Classical or Pavlovian Conditioning
Pavlov’s device for recording salivation
Classical or Pavlovian Conditioning
Unconditioned Stimulus (UCS) effective stimulus that unconditionally-
naturally and automatically - triggers a response
Unconditioned Response (UCR) unlearned, naturally occurring response
to the unconditioned stimulussalivation when food is in the mouth
Classical or Pavlovian Conditioning
Conditioned Stimulus (CS) originally neutral stimulus that, after
association with an unconditioned stimulus, comes to trigger a conditioned response
Conditioned Response (CR) learned response to a previously neutral
conditioned stimulus
Pavlov’s Classic Experiment
Before Conditioning
During Conditioning After Conditioning
UCS (foodin mouth)
Neutralstimulus(tone)
Nosalivation
UCR (salivation)
Neutralstimulus(tone)
UCS (foodin mouth)
UCR(salivation)
CS(tone)
CR (salivation)
Classical or Pavlovian Conditioning
Acquisition the initial stage of learning, during which
a response is established and gradually strengthened
the phase associating a neutral stimulus with an unconditioned stimulus so that the neutral stimulus comes to evoke a conditioned response
Classical or Pavlovian Conditioning
UCS(passionate kiss) UCR
(sexualarousal)
CS(onionbreath)
CS(onion breath) CR
(sexualarousal)
UCS(passionate Kiss) UCR
(sexualarousal)
Classical or Pavlovian Conditioning
Extinction diminishing of a conditioned
response in classical conditioning, when
an unconditioned stimulus does not follow a conditioned stimulus
Classical or Pavlovian Conditioning
Strengthof CR
Pause
Acquisition(CS+UCS)
Extinction(CS alone)
Extinction(CS alone)
Spontaneousrecovery ofCR
Weak
Strong
Time
Classical or Pavlovian Conditioning
Spontaneous recovery reappearance, after a rest period, of
an extinguished conditioned responseGeneralization
tendency, once a response has been established, for stimuli similar to the conditioned stimulus to evoke similar responses
GeneralizationDrops of salivain 30 seconds
60
50
40
30
20
10
0Hindpaw
Pelvis Shoulder Frontpaw
Thigh Trunk Foreleg
Part of body stimulated
Classical or Pavlovian Conditioning
Discrimination in classical conditioning, the
ability to distinguish between a conditioned stimulus and other stimuli that do not signal an unconditioned stimulus
Nausea Conditioning among Cancer Patients
UCS(drug)
UCR(nausea)
CS(waiting room)
CS(waitingroom) CR
(nausea)
UCS(drug)
UCR(nausea)
Little Albert’s Fear Conditioning
UCS(loud noise)
UCR(fear)
CS(rat)
CS(rat)
CR(fear)
UCS(loud noise)
UCR(fear)
Stimulus similarto rat (such as rabbit)
Conditioned fear(generalization)
Operant Conditioning
Operant Conditioning type of learning in which behavior is
strengthened if followed by reinforcement or diminished if followed by punishment
Law of Effect Thorndike’s principle that rewarded
behavior is likely to recur
Operant Conditioning
Operant Behavior complex or voluntary behaviors
push button, perform complex task
operates (acts) on environment produces consequences
Respondent Behavior occurs as an automatic response to
some stimulus
Operant Conditioning
B.F. Skinner (1904-1990) elaborated
Thorndike’s Law of Effect
developed behavioral technology
Operant Conditioning
Operant Chamber (“Skinner Box”)
Operant Conditioning
Reinforcer any event that strengthens the
behavior it followsShaping
operant conditioning procedure in which reinforcers guide behavior toward closer approximations of a desired goal
Principles of Reinforcement
Primary Reinforcer an innate reinforcer satisfies a biological need
Secondary Reinforcer a conditioned reinforcer
Schedules of ReinforcementContinuous Reinforcement
reinforcing the desired response each time it occurs
extinction occurs rapidlyPartial Reinforcement
reinforcing a response only part of the time results in slower acquisition greater resistance to extinction
Schedules of Reinforcement
Fixed Ratio (FR) schedule that reinforces a response
only after a specified number of responses
the faster you respond, the more rewards you get
different ratios very high rate of responding like piecework pay
Schedules of Reinforcement
Variable Ratio (VR) schedule that reinforces a
response after an unpredictable number of responses
like gambling, fishing very hard to extinguish because
of unpredictability
Schedules of Reinforcement
Fixed Interval (FI) a schedule that reinforces a
response only after a specified time has elapsed
response occurs more frequently as the anticipated time for reward draws near
Schedules of Reinforcement
Variable Interval (VI) schedule that reinforces a
response at unpredictable time intervals
produces slow, steady responding like pop quiz
Schedules of Reinforcement
Variable Interval
Number of responses
1000
750
500
250
010 20 30 40 50 60 70
Time (minutes)
Fixed Ratio
Variable Ratio
Fixed Interval
Steady responding
Rapid respondingnear time forreinforcement
80
Punishment
Punishment aversive event that
decreases the behavior that it follows
Problems with Punishment
Punished behavior is not forgotten, it's suppressed--
Causes increased aggression- shows that aggression is a way to cope with problems-- explains why aggressive delinquents and abusive parents come from abusive homes
Problems with Punishment
Creates fearDoes not necessarily guide toward desired
behavior--Punishment teaches how to avoid it
Operant vs Classical Conditioning
Comparison of Classical and Operant ConditioningClassical Conditioning Operant Conditioning
The response Involuntary, automatic “Voluntary,” operates on environment
Acquisition Associating events; CS announces Associating response with a conse- UCS. quence (reinforcer or punisher).
Extinction CR decreases when CS is repeatedly Responding decreases when reinforce- presented alone. ment stops.
Cognitive Subjects develop expectation that Subjects develop expectation that a processes CS signals the arrival of UCS response will be reinforced or punished;
they also exhibit latent learning, without reinforcement.
Biological Natural predispositions constrain Organisms best learn behavior similar to predispositions stimuli and responses can easily be their natural behaviors; unnatural be- associated. haviors instinctively drift back toward
natural ones.
Observational Learning
Observational Learning learning by observing and imitating the
behavior of othersModeling
process of observing and imitating behavior
Prosocial Behavior positive, constructive, helpful behavior opposite of antisocial behavior