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Learning
1
Overview2
How do we develop passions, aversions, and responses to so many objects and activities?
3
Some of these objects and activities evolved after our birth—like a passion or aversion to Facebook
4
Such passions, aversions, & responses cannot be innate
5
Classical conditioning explains many of these tendencies
6
Classical conditioning was discovered by Ivan Pavlov
7
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
Ivan Pavlov, a Russian researcher, was interested in
the sources of salivation 8
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
He wanted to determine which foods and conditions promoted salivation in dogs
9
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
To examine this issue, he developed a means to
measure salivation in dogs10
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
In essence, the salivary gland, was connected to a clear tube
that dripped into a beaker11
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
Each food would evoke different levels of salivation
12
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
But gradually he noticed something unusual
13
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
When he or his assistant entered the room, the
dog would salivate14
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
Dogs could not have evolved to recognize Russian scientists
15
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
He decided to study this anticipation
16
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
A metronome was activated before food was presented
17
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
Later, a metronome without food evoked salivation
18
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
If a signal tends to precede an event that provokes a reflex…
19
Pavlov’s conclusion
Pavlov’s discovery
Pavlov’s objectives
this signal alone will evoke the reflex…
20
Classical conditioning extends reflexes to new situations
21
What are reflexes? 22
Reflexes are unlearned, involuntary responses to stimuli
23
Stepping reflex
Swimming reflex
Grasping reflex
When placed in water, hold breath; move arms & legs
24
Stepping reflex
Swimming reflex
Grasping reflex
Disappears after 4-6 months
25
Stepping reflex
Swimming reflex
Grasping reflex
When held upright, with their feet touching the ground
26
Stepping reflex
Swimming reflex
Grasping reflex
They will step, as if walking
27
Stepping reflex
Swimming reflex
Grasping reflex
Unless practiced often, disappears after 8 weeks
28
Stepping reflex
Swimming reflex
Grasping reflex
If touch palm, babies curl their finger around your finger
29
Stepping reflex
Swimming reflex
Grasping reflex
After 3 to 4 months, replaced by a voluntary grasp
30
Classical conditioning also extends to involuntary acts that are learned, called elicited behaviours
31
Classical conditioning can also explain fears
32
Conclusion from this finding
Little Albert afterwards
Little Albert initially
Little Albert was a happy child, with no obvious problems
33
Conclusion from this finding
Little Albert afterwards
Little Albert initially
But he was subjected to an experiment…
34
Conclusion from this finding
Little Albert afterwards
Little Albert initially
He received electric shocks whenever a rat approached
35
Conclusion from this finding
Little Albert afterwards
Little Albert initially
He became fearful and avoidant of rats as a consequence
36
Conclusion from this finding
Little Albert afterwards
Little Albert initially
This fear even generalized to other animals such as rabbits
37
Conclusion from this finding
Little Albert afterwards
Little Albert initially
Perhaps classical conditioning can explain phobias…
38
Suppose a sound always precedes an electric shock
39
Over time, people associate the sound with the shock
40
The sound itself is sufficient to evoke fear or phobias
41
Conclusion from this finding
Little Albert afterwards
Little Albert initially
But his experience does not typify phobias in general
42
Conclusion from this finding
Little Albert afterwards
Little Albert initially
Unlike Little Albert, one pairing is enough to generate phobias
43
The study was actually flawed & not only unethical
44
The results, for example, were quite mixed.
45
Nomenclature 46
The concept is simple… The nomenclature is confusing…
47
You need to learn five terms
48
• neutral stimulus • unconditioned stimulus and unconditioned response • conditioned stimulus and conditioned response
49
The metronome is initially a neutral stimulus—not associated with a particular response
Neutral stimulus
Unconditioned stimulus
Unconditioned response
50
The food and salivation are called unconditioned.They are innate rather than conditioned over time.
Neutral stimulus
Unconditioned stimulus
Unconditioned response
51
Over time, the metronome is conditioned to evoke salivation—and is called the conditioned stimulus
Conditioned stimulus
Conditioned response 52
Yet, the metronome produces less salivation than food
Conditioned stimulus
Conditioned response 53
We distinguish the conditioned & unconditioned response
Conditioned stimulus
Conditioned response 54
Abbreviations of these terms: NS, US, UR, CS, and CR
55
56
Observations 57
FAQ: Will the metronome evoke salivation after preceding the food say 5 times?
58
That is, how many pairings are necessary
59
CR
inte
nsi
ty li
ke s
aliv
atio
n
Number of paired stimuli
60
CR
inte
nsi
ty li
ke s
aliv
atio
n
Number of paired stimuli
No precise number
61
CR
inte
nsi
ty li
ke s
aliv
atio
n
Number of paired stimuli
A few pairings might evoke a modest CR
62
Overview Nomenclature Observations
Stimulus-response Substitution Preparation
CR
inte
nsi
ty li
ke s
aliv
atio
n
Number of paired stimuli
Many pairings evoke stronger CRs
63
CR
inte
nsi
ty li
ke s
aliv
atio
n
Number of paired stimuli
…until a plateau is reached
64
FAQ: Can the metronome precede the food by 1 hour?
65
or appear at the same time or after the food?
66
What is the optimal timing of the NS and US?
67
To answer this question, consider four arrangements…
68
Delayed: The NS precedes but overlaps with the US
Delay
69
This arrangement facilitates conditioning
70
After a few pairings, the metronome will evoke salivation
71
Trace: The NS precedes but does not overlap with the US
Only a trace of the sound remains
72
Prevents conditioning unless organism is concentrating
Only a trace of the sound remains
73
and the hippocampus, vital to memory, is intact
74
Simultaneous impedes conditioning
75
Backward--the NS follows the US--impedes conditioning
76
But simultaneous and backward can be effective if…
77
the neutral stimulus has been significant during evolution
78
Consider this example
79
Suppose the sound always followed the shock
80
This backward arrangement will not enable conditioning
81
But now suppose the NS is significant, like a snake
82
The snake does become conditioned to provoke fear
83
Why?
84
Perhaps we are more sensitive to objects that have been significant, or threatening, during evolution
85
Complications86
Suppose you want to feel inspired by the textbook
87
Before each event that could be inspiring, like a movie
88
you should read the book. The book will become a CS
CS US UR
89
That is, over time, the book will elicit inspiration
CS CR
90
But actually many complications need to be addressed
CS CR
91
One complication is called overshadowing
92
Example: If the book coincides with an intense stimulus
CS URUS
93
such as listening to loud music
CS URUS
Introduction Formula Classical
Over-expectation Contradictions Refinements94
the intense stimulus is conditioned
CS CR
Introduction Formula Classical
Over-expectation Contradictions Refinements95
The loud music, even by itself, will evoke inspiration
CS CR
96
But the other stimulus—the book—is not conditioned
97
The book will not elicit inspiration
98
The intense stimulus overshadowed the other stimulus
Refinements99
A second complication is called blocking
100
If you wear the same clothes before each inspiring event
101
these clothes will become conditioned to the stimulus
CS US UR
102
That is, the clothes even by itself will evoke inspiration
CS CR
103
But if you now also read the text before inspiring events
104
the book will not be conditioned or evoke inspiration
105
Why not?
106
That is, how did the clothes block this conditioning?
107
Because the clothes already predict the US
CS US
108
The book does not help us predict the US
CS US
109
So the book in essence is disregarded
CS US
110
A third complication is called latent inhibition
Introduction Formula Classical
Over-expectation Contradictions Refinements111
Example: If the book coincides with an unfamiliar object
CS URUS
112
the unfamiliar stimulus is conditioned
CS CR
113
That is, the unfamiliar sound by itself evokes inspiration
CS CR
114
But the other stimulus—the book—is not conditioned
115
The book will not elicit inspiration
116
The unfamiliar stimulus inhibited the other stimulus
117
But how does the NS evolve into a CS?
118
What cognitive processes underlie this change?
119
Some researchers ascribed classical conditioning to a stimulus response model
120
That is, individuals learn to associate the neutral stimulus with the unconditioned response
121
The neutral stimulus will thus prime the unconditioned response
122
The sound is associated with salivation & other activities
123
So the sound alone primes salivation & other activities
124
But this model cannot explain some interesting findings
125
One example is sign tracking
126
Sign tracking is the tendency of organisms to approach a stimulus that tends to precede a pleasant event…
127
Suppose a light always precedes food and thus pecking
Neutral stimulus
Unconditioned stimulus
Unconditioned response
128
Unsurprisingly the light will evoke pecking
129
But the pigeon also pecks at the light
130
Could not be ascribed to a stimulus-response model
131
The pigeon had never pecked at the light initially. So the light was never associated with this behaviour
132
Instead, the pigeon seemed to substitute the light & food
133
The pigeons regarded the light and food as equivalent, called a stimulus-stimulus model
134
But organisms do not always apply the same behaviour to the CS and US—contrary to the substitution model
135
Heroin tends to decrease blood pressure
Decrease blood
pressure
136
But cues that precede heroin increase blood pressure
Increase blood
pressure
137
So heroin and its precursors could not be substitutes—because they evoke different responses
Increase blood
pressure
138
Perhaps the precursors—and all CSs—evoke a tendency to prepare before the US is presented
139
That is, suppose these cues always precede heroin use—and this heroin use tends to decrease blood pressure
Decrease blood
pressure
140
The cue thus precedes a decrease in blood pressure
Decrease blood
pressure
141
Overview Nomenclature Observations
Stimulus-response Substitution Preparation
To compensate, the cue increases blood pressure
Decrease blood
pressure
142
The cue thus evokes a preparatory response
Decrease blood
pressure
143
Perhaps stimulus-response, stimulus substitution, and response preparation all apply in various settings
144
Operant conditioning 145
Nomenclature of operant conditioning 146
To describe this theory, specific labels are often used
147
Individuals are exposed to some setting or stimulus
148
called the antecedent or discriminating stimulus
Antecedent
149
They choose some behaviour in response, like press a bar
Antecedent Behaviour
150
and receive some outcome as a consequence, like milk
Antecedent Behaviour Consequence
151
If the consequence is pleasant, they will repeat this act
Antecedent Behaviour Consequence
152
Pleasant consequences are called reinforcers or rewards
Antecedent Behaviour Consequence
153
If the consequence is unpleasant, they will inhibit this act
Antecedent Behaviour Consequence
154
Unpleasant consequences are called punishers
Antecedent Behaviour Consequence
155
Positive versus negative reinforcers and punishers156
Besides reinforcers and punishers…
157
consequences can be divided into positive or negative
158
Oddly, not the same as pleasant and unpleasant !
159
Positive—added to. Negative—withdrawn from
160
Consider these examples
161
Positive reinforcement: Adding pleasant thing
162
like receiving ice cream after studying
163
Negative reinforcement: withdrawing unpleasant thing
164
like removing handcuffs or some other restriction
165
Positive punishment: adding unpleasant thing
166
like receiving a smack
167
Negative punishment: removing pleasant thing
168
like removing the right to leave the house
Introduction Nomenclature Delays
Reinforce vs punish Predictions Positive vs negative169
Why do we distinguish positive & negative outcomes?
170
Because positive consequences affect some people,
171
and negative consequences affect other people more
172
How do you reinforce acts the are not initiated otherwise
173
Apply shaping
174
To illustrate, suppose you want a dog to shake hands
175
Initially reinforce sitting
176
Then reinforce only acts that are closer to shaking
177
like sitting with one paw in the air
178
Then reinforce only acts that are even closer to shaking
179
like the paw touching a hand
180
Eventually reinforce only the desired act of shaking
181
Shaping can be used to develop social skills too
182
Example: Socially withdrawn girl who spoke too quietly
183
Initially, if she exceeded 20 dB, she was rewarded
“Excellent”21
184
Then, if she exceeded 25 dB, she was rewarded
“Excellent”21
“Excellent”28
185
Eventually, if she exceeded 50 dB, she was rewarded
“Excellent”21
“Excellent”28 “Excellent”
“Excellent”32 “Excellent”“Excellent”
“Excellent”52
186
Did you know when people speak louder and act extraverted their mood, & thus social skills, improve
187
Shaping has also been shown to overcome stuttering
Aim Prompting & fading New behaviours
Habits Openness Transfer 188
Person is reinforced for increasing rate of speech
Aim Prompting & fading New behaviours
Habits Openness Transfer 189
Classical versus operant conditioning
190
Classical conditioning extends our innate tendencies to a broader range of settings
191
For example, we innately smile in response to warmth
192
If a parent always coincides with this warmth…
193
the parent alone will evoke a smile
194
The smile is elicited in a broader range of settings
195
But respondent conditioning does not extend our repertoire of behaviours
196
Operant conditioning does extend our repertoire of behaviours
197
That is, in response to various events, we attempt variations of existing behaviours
198
Behaviours that are rewarded, not punished, are repeated and, over time, modified
199
Without operant conditioning, we would still attempt a diversity of behaviours but…
200
these behaviours would not become increasingly useful
201
Reinforcement schedules 202
How can you inspire children to tell the truth?
203
Perhaps each time the child concedes or discloses a fault,
I was rude
today
204
you could offer reassurance—a positive reinforcement
That’s OK; you’re
usually very good
I was rude
today
205
But this approach generates two problems
I was rude
today
206
First, you might be unable to reinforce each disclosure
207
For example, you might be distracted or far away
I was rude
today
208
Second, if you fail to reinforce only a few times,
I was
rude…
I was
rude…
I was
rude…
209
the behaviour will tend to vanish or extinguish quickly
I was
rude…
I was
rude…
I was
rude…
210
So how can you prevent these problems?
211
Reinforce after only a portion of suitable behaviors
212
Example: You could reinforce after every third disclosure
I was
rude… I was
rude… I was
rude…
I was
rude… I was
rude… I was
rude…
213
or after a delay of at least 1 hourI was
rude…
I was
rude…
I was
rude…
2.00 pm 4.00 pm 6.00 pm
I was
rude…
214
• Continuous reinforcement: Reinforce after each time• Intermittent reinforcement: Do not reinforce each time
215
Types of intermittent schedules 216
Intermittent schedules are classified as rate or interval
217
If you reinforce after every x acts, like 3 disclosures
I was
rude… I was
rude… I was
rude…
I was
rude… I was
rude… I was
rude…
218
the arrangement is called a rate schedule
I was
rude… I was
rude… I was
rude…
I was
rude… I was
rude… I was
rude…
219
Why is this arrangement called a rate schedule
220
bc the child is reinforced at a rate of 1 per 3 disclosures
221
If you reinforce an act only after a delay, such as 1 hour
I was
rude…I was
rude…
I was
rude…
2.00 pm 4.00 pm 6.00 pm
I was
rude…
222
the arrangement is called an interval scheduleI was
rude…
I was
rude…
I was
rude…
2.00 pm 4.00 pm 6.00 pm
I was
rude…
223
bc the child is reinforced only after an interval of 1 hour
224
Note the child is not always reinforced after an hourI was
rude…
I was
rude…
I was
rude…
2.00 pm 4.00 pm 6.00 pm
I was
rude…
225
Instead the first disclosure after this hour is reinforcedI was
rude…
I was
rude…
I was
rude…
2.00 pm 4.00 pm 6.00 pm
I was
rude…
226
Rate and interval schedules can also be divided…
227
into fixed and variable
228
Fixed rate: Child is reinforced after exactly 3 disclosures
I was
rude… I was
rude… I was
rude…
I was
rude…I was
rude…I was
rude…
229
Variable: Child is reinforced after 3 disclosures on average
I was
rude… I was
rude…
I was
rude… I was
rude…I was
rude…I was
rude…
230
Why do we need to know about these schedules?
231
Each schedule is common in real life
232
and generates different effects
233
Examples of intermittent schedules 234
Here are some typical examples
235
Many states resemble death
…. … …
… … …Each time salespeople sell 5 home loans, they receive a $100 bonus
Fixed rate
Fixed interval
Variable rate
Variable interval236
Many states resemble death
…. … …
… … …So, the act is the sale, and
the reinforcement is the bonus
Fixed rate
Fixed interval
Variable rate
Variable interval237
Many states resemble death
…. … …
… … …called fixed rate 5 or FR 5
Fixed rate
Fixed interval
Variable rate
Variable interval238
Many states resemble death
…. … …
… … …Slot machines pay a bonus after
about 10 lever presses on average
Fixed rate
Fixed interval
Variable rate
Variable interval239
Many states resemble death
…. … …
… … …The behaviour is pressing a lever; the reinforcement is the money
Fixed rate
Fixed interval
Variable rate
Variable interval240
Many states resemble death
…. … …
… … …called variable rate 10 or VR10
Fixed rate
Fixed interval
Variable rate
Variable interval241
Many states resemble death
…. … …
… … …To teach children to be quiet, you
serve food only when they are quiet
Fixed rate
Fixed interval
Variable rate
Variable interval
7.00 am 1.00 pm 6.00 pm
242
Many states resemble death
…. … …
… … …but only after an interval of at least 5
hours from their previous meal
Fixed rate
Fixed interval
Variable rate
Variable interval
7.00 am 1.00 pm 6.00 pm
243
Many states resemble death
…. … …
… … …Called fixed interval 5 or FI5
Fixed rate
Fixed interval
Variable rate
Variable interval
7.00 am 1.00 pm 6.00 pm
244
Many states resemble death
…. … …
… … …Or, if the minimum delay varied
but was 5 hours on average
Fixed rate
Fixed interval
Variable rate
Variable interval
7.00 am 1.00 pm 6.00 pm
245
Many states resemble death
…. … …
… … …the schedule is VI5 instead
Fixed rate
Fixed interval
Variable rate
Variable interval
7.00 am 1.00 pm 6.00 pm
246
Benefits of the various intermittent schedules 247
So which schedule is preferable?
248
And what is the effect or benefit of each schedule?
249
These effects vary on four attributes
250
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction Variable interval generates the most responses
FR VR
FI VI
251
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction Why?
FR VR
FI VI
252
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction If fixed interval, bc of the delay, frequent responses are not always reinforced
FR VR
FI VI
253
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction So rate of responses diminishes
FR VR
FI VI
254
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction If variable, reinforcement may be very soon—enhances energy
FR VR
FI VI
255
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction For fixed, we may know the reward will not arrive until 6 actions later256
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction For variable, the reward could be sooner, igniting anticipation 257
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction Could explain why some people gamble so often
FR VR
FI VI
258
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction because any moment they could enjoy a reward
FR VR
FI VI
259
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction For rate schedules, the responses are evenly distributed over time
Time
260
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction For interval schedules, the responses escalate just before the delay ends
7.00 am 1.00 pm 6.00 pm
261
Many states resemble death
…. … …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction rather than earlier
7.00 am 1.00 pm 6.00 pm
262
Many states resemble death
…. …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction
FR VR
FI VI
If fixed, often refrain from response immediately after the reward263
Many states resemble death
…. …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction
FR VR
FI VI
If variable, still respond immediately after the reward264
Many states resemble death
…. …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction
FR VR
FI VI
because, in these settings, an immediate reward is still possible 265
Many states resemble death
…. …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction
FR VR
FI VI
Finally, after you withdraw reinforcement altogether 266
Many states resemble death
…. …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction
FR VR
FI VI
responses will not vanish or extinguish as immediately if variable267
Many states resemble death
…. …
… … …
Rate of response
Pause after reinforcement
Distribution of responses
Extinction
FR VR
FI VI
Because of the variability, not as sure the reinforcement has vanished268
Observational learning
269
At one time, researchers assumed that people will learn only from the experiences in which they participated
270
Classical conditioning: People learn only when they experience the unconditioned response, like salivating
271
Operant conditioning : People learn only if they receive a reward or punishment themselves
272
Overview Bobo 1961 study Bobo 1963 study
Role of attention Ubiquity
Albert Bandura challenged
this assumption
Role of motivation 273
Overview Bobo 1961 study Bobo 1963 study
Role of attention Ubiquity
He showed that people—and even many animals—can learn merely by watching other individuals
Role of motivation 274
Overview Bobo 1961 study Bobo 1963 study
Role of attention Ubiquity
Observing and participating in some activity is more effective than either of these modes alone
Role of motivation 275
1961 Bobo study
276
A famous study with Bobo, a doll, illustrated his theory
277
Phase 1
Phase 2
Measures
Results
During Phase 1, some children observed violence
278
Phase 1
Phase 2
Measures
Results
That is, 3 to 6 year old children played in one
corner of a room 279
Phase 1
Phase 2
Measures
Results
while an adult played in another corner
280
Phase 1
Phase 2
Measures
Results
The adult played with some toys including a
mallet and a doll: Bobo281
Phase 1
Phase 2
Measures
Results
Half the children watched an aggressive adult—saying “Pow”, using a mallet…
282
Phase 1
Phase 2
Measures
Results
The other children watched an adult who did not play with Bobo
283
Phase 1
Phase 2
Measures
Results
Did observing aggression affect their behaviour?
284
Phase 1
Phase 2
Measures
Results
Phase 2 was designed to answer this question
285
Phase 1
Phase 2
Measures
Results
After playing with fun toys, the children were told to shift
rooms—to evoke frustration
286
Phase 1
Phase 2
Measures
Results
In the other room were some modest toys and Bobo
287
Phase 1
Phase 2
Measures
Results
A variety of behaviours were coded to assess the hypotheses
288
Phase 1
Phase 2
Measures
Results
• Physical aggression, like kicking
• Verbal aggression, like yelling
• Mirroring adults, using the mallet
289
Phase 1
Phase 2
Measures
Results
If exposed to aggression, children were more likely to
demonstrate aggression
290
Phase 1
Phase 2
Measures
Results
especially in boys, particularly when
the adult was male
291
1963 Bobo study
292
The 1963 study was similar except…
293
First, the children watched only a film of the adult
294
Second, the adult was either rewarded with food or punished with an angry warning or tirade
295
Third, both the memory of this film and behaviour of the children were assessed
296
Again, children mirrored the aggressive adult—but only if this adult was rewarded
297
Yet the reward did not improve memory of aggression
298
So, the rewards or punishment that other people receive affect behaviour but not memory
299
…the determinants of learning & performance differ
300