Download Simple learning processes

Today’s Class
•
•
•
•
What is learning?
Types/classes of learning
Adaptive significance
Extending the domain
TA Judith Asem
You asked for it…
• What: Review Session with Judith
first half of material for Exam 2 (4/4)
• When: Tuesday, 3/12
6:30-8:00pm
• Where: Krieger 205
Attention, Learning, and Memory
external sensory information
+ internal representations (ideas)
= adaptive responses
PERCEPTION
receive
information
LEARNING
acquire
knowledge from
information
MEMORY
store and retrieve
knowledge
Learning
• Alters behaviors
– Overt vs. covert behaviors
• What was learned?
• We see a change in behavior
Social Interaction
Types/Classes of Learning
―Simple‖ learning processes
• Nonassociative
– Objects and events
• Associative
– Relationships
―Complex‖ learning processes
• To be continued…
Goal: to make a behavior
amenable to scientific study!
Nonassociative Learning
• Exposed once or
repeatedly to a single
type of stimulus
• Consider reflexes
Aplysia (―sea slug‖)
Nonassociative learning
• Habituation
– First to occur in infants
– ↓ response
• Sensitization
– Strong or noxious
stimulus
– ↑ response
Nonassociative (Event) Learning
• Habituation
Habituation of startle response
35
Magnitude of startle response
30
25
20
15
10
5
0
1
3
5
7
9
11
13
15
Trials
17
19
21
23
25
27
Nonassociative (Event) Learning
• Habituation
• Dishabituation
Habituation and dishabituation of startle response
35
Magnitude of startle response
30
25
20
15
10
5
0
1
3
5
7
9
11
13
Trials
15
17
19
21
23
25
Nonassociative (Event) Learning
• Habituation
• Dishabituation
• Sensitization
Habituation and dishabituation of startle response
35
Magnitude of startle response
30
25
20
15
10
5
0
1
3
5
7
9
11
13
Trials
15
17
19
21
23
25
Nonassociative (Event) Learning
Habituation
Dishabituation
Sensitization
Synaptic basis of
habituation and
sensitization
Habituation and dishabituation of startle response
35
30
Magnitude of startle response
•
•
•
•
25
20
15
10
5
0
1
3
5
7
9
11
13
Trials
15
17
19
21
23
25
Associative Learning
• Classical/Pavlovian Conditioning
– Event-event learning
– Stimuli and events
– Pavlov’s dog
• Operant/Instrumental Conditioning
– Behavior-event learning
– Consequences of behavior
– Types of reinforcers
• Acquiring information about relationships between
stimuli/events, behavior, and consequences
Classical Conditioning
Pairing: CS US  UR
species-typical behavior
Classical (Pavlovian) Conditioning
CS - CR
Why?
What about in the real world? The Office
Pavlovian Conditioning
bell
(CS)
food
(US)
orient
(OR)
salivate
(UR)
salivate
(CR)
CS = conditioned stimulus
US = unconditioned stimulus
OR = orienting response
CR = conditioned response
UR = unconditioned response
Pavlovian Conditioning
bell
(CS)
food
(US)
orient
(OR)
salivate
(UR)
CS = conditioned stimulus
US = unconditioned stimulus
OR = orienting response
CR = conditioned response
UR = unconditioned response
salivate
(CR)
Pavlovian conditioning as learned adaptation.
Pavlovian conditioning as knowledge acquisition.
Adaptive Significance
Pavlovian conditioning as learned adaptation.
• Emotional behavior
– Incentive motivation
and hunger
– Fear and anxiety
– Phobias
– Role of amygdala
Adaptive Significance
Pavlovian conditioning as learned adaptation.
• Emotional behavior
– Incentive motivation
and hunger
– Fear and anxiety
– Phobias
– Role of amygdala
• Biological responses
–
–
–
–
Digestion
Immune responses
Analgesia
Drug tolerance and
addiction
– Anticipatory (proactive)
regulation
Acquisition of Pavlovian Associations
Pavlovian conditioning as knowledge acquisition.
• Stimulus-stimulus (S-S) vs stimulus-response (S-R) associations
– Learning ―how‖ vs. learning ―what‖ (procedural vs declarative)
– ―Light means slobber‖ vs ―Light means food‖
– Devaluation experiment (―behavioral syllogism‖):
• Light—food
Men are mortal
• Food—illness Craig is a man
• Light?
Craig is mortal
Test after devaluation
60
50
40
% CR
Maintain: Light—food | food—illness | light?
Devalue: Light—food | food /// illness | light?
30
20
10
0
Maintain
•
Role of prefrontal cortex, amygdala vs striatum
Devalue
Group
Acquisition of Pavlovian Associations
Pavlovian conditioning as knowledge acquisition.
Acquisition of Pavlovian CR
30
25
Drops of saliva
20
15
10
5
0
1
2
3
4
5
6
Trial (CS-US)
7
8
9
Acquisition of Pavlovian Associations:
Interstimulus Interval
Interstimulus-interval (ISI) function
100
90
80
Percent CRs
70
60
50
40
30
20
10
0
-10
-1000
-500
0
500
1000
1500
2000
2500
3000
CS-US interval (m sec)
Condition for learning or content of learning?
Acquisition of Pavlovian Associations:
Cue to Consequence
60
Garcia Experiment
40
% CR
Bright+Noisy,Tasty -- illness
-orBright+Noisy,Tasty -- pain
50
tasty
bright+noisy
30
20
10
0
illness
pain
US
Extending Pavlovian Associations:
Generalization
Generalization
100
% response
80
60
40
20
0
1000
2000
3000
4000
5000
6000
Tone Frequency (herz)
7000
8000
9000
Extending Pavlovian Associations:
Second-Order Conditioning
Second-order conditioning
50
Unpaired:
light—food | tone /// light
40
% response
Paired:
light—food | tone—light
30
Paired
Unpaired
20
10
0
1
2
3
Sessions
4
5
Extending Pavlovian Associations:
Sensory Preconditioning
Sensory preconditioning
30
Paired:
tone—light | light—food | tone?
25
Unpaired:
tone /// light | light—food | tone?
% CR
20
15
10
5
0
Paired
Unpaired
Group
Associative Learning
• Classical/Pavlovian Conditioning
– Event-event learning
– Stimuli and events
– Pavlov’s dog
• Operant/Instrumental Conditioning
– Behavior-event learning
– Consequences of behavior
– Types of reinforcers
• Acquiring information about relationships between
stimuli/events, behavior, and consequences
Instrumental/Operant Conditioning
Instrumental
Operant
(Thorndike)
(Skinner)
Pairing: R - Rif
Instrumental/Operant Conditioning
More flexible, adaptive form of learning
Reinforcement
What is the consequence?
Appetitive
(approach)
Positive Rif
Negative Rif
Aversive
(escape)
Reinforcers
primary (unlearned) reinforcers
Reinforcers
secondary (conditioned) reinforcers
Second-Order Conditioning
• Human and nonhuman animals can learn hierarchical
associations.
• Light  Tone  Food
• Animals will ―work‖ to get the light.
• But why?
– It is, eventually, paired with food.
In the Laboratory
What about in the real world? Big Bang Theory
Types/Classes of Learning
―Simple‖ learning processes
• Nonassociative
– Objects and events
• Associative
– Relationships
―Complex‖ learning processes
• To be continued…
Goal: to make a behavior
amenable to scientific study!
Today’s Class
• What is learning?
• Types/classes of simple learning processes
– Nonassociative
• Habituation and Sensitization
– Associative
• Pavlovian/Classical and Operant/Instrumental
• Adaptive significance
– Emotional behavior and biological responses
– Learned adaptation and knowledge acquisition
• Extending the domain
– Generalization, second-order conditioning, sensory
preconditioning
– Reinforcement and reinforcers
Attention, Learning, and Memory
external sensory information
+ internal representations (ideas)
= adaptive responses
PERCEPTION
receive
information
LEARNING
acquire
knowledge from
information
MEMORY
store and retrieve
knowledge
You asked for it…
• What: Review Session
first half of material for Exam 2 (4/4)
• When: Tuesday, 3/12
6:30-8:00pm
• Where: Krieger 205