Transcript Chapter 4 Learning Learning: What does it mean to learn?

Chapter 4 Learning
Learning: What does it mean to
learn?
• Learning is the single largest area of
Psychology second only to clinical
psychology
Habituation
• Works at the neuron level to organismic
level
I. Classical Conditioning –
learning through association
• Philosophical roots: English Empiricists
• John Locke – Primary and Secondary
Qualities
• David Hume – Reflection , Cause and
Effect
Ideas
• Anything that stimulates the CNS
1. Pavlov and the conditioned
reflex
• The procedure is what distinguishes
classical conditioning from other modes of
learning
Condition Stimulus (CS)
• A neutral stimulus, can be sound, light or
internal craving.
Uncondition Stimulus (UCS)
• The natural stimulus that drives a reflex
Uncondition response (UCR)
• The basic reflex that is to become
controlled by procedure
Condition Response (CR)
• The response when driven by the
Condition Stimulus
2. Major phenomena of classical
• Two types of procedures
Delay conditioning
Delay Conditioning
Trace Conditioning
3 Characteristics of Delay
Conditioning
• The CS starts before the UCS
• There is a time period between when the
CS in On and the start of the UCS – know
as the Inter-Stimulus-Interval (ISI).
• Both the CS and the UCS co-terminate.
Pavlov’s study
• Condition stimulus was the sound of a
metronome
• The Uncondition Stimulus (UCS) was
meat powder
• The uncondition response was drops of
salivation
• Condition response was salivation
Trial presentation
• Trials are presented singularly and
continues until some criterion is met or a
fixed number of trials completed.
Paired trials
• When both the CS and the UCS are
presented in a fixed order and time frame.
CS Alone Trials
• Periodically only the CS is presented
• Known as CS alone trials.
Statistics
• Mean and SD change in the timing or
magnitude of the paired trials.
• Mean and SD of the CS alone trials
Results
• In the beginning trials the CS does not
elicit the CR
• Across trials there is a change in the ability
of the CS to drive the CR.
• By the end of the trials, both for paired and
CS alone trials the CS is able to elicit the
CR.
Response Measures
• Magnitude increases, time shortens or
frequency changes for the behavior
How does one know that one has
stimulus control
• Use Extinction trials
Present the trials in the manner of
Habituation
• Repeated presentation of the CS alone will
drive the changes that were learned during
CS presentation to zero.
EXTINCTION
Eyeblink Studies
• First done by Ernest Hilgard in humans,
dogs and monkeys.
• Modern Studies were started by Isidore
Gormenzano
Mauk Studies
What Is The Behavior Measured
• A very sharp distinguishable criterion of
what constitutes the movement of an
eyelid.
Eyelid Movement Changed to an
Electrical Potential
• An Stainless Steel Wire (0.007 in. by
0.018 cm) Extended From the suture loop
in the eyelid to a phototransistor
Potentiometer
• The movement of the eyelid, closure
distance in cm, was changed to voltage by
the potentiometer.
CS
• Sine Waves of Various Frequencies
presented at an intensity of 80dB (SPL)
UCS Airpuff
• UCS was calibrated to present to the eye
and airpuff of 2 N/cm2 delivered to the
cornea of the rabbit through, a 1 mm
tuberculin syringe, positioned
approximately 1 cm from the cornea.
Criterion Learning
• How Many Trials to Learn to a Fixed
Criterion: Eight Correct Closures Out of
Ten.
Fixed Trial Procedure
• Percent of Closures in X Number of Trials
Most Frequently Used Procedure
• Total of 108 Trials Divided in 12 Blocks
• First Trial of each block is a CS Alone Trial
• ACROSS 108 TRIALS: 12 CS ALONE
TRIALS AND 12 BLOCKS OF PAIRED
CS/UCS TRIALS
What IS MEASURED
• NUMBER OF TRIALS IN WHICH AN
EYEBLINK WAS MADE
• LATENCY to ONSET: TIME IT TAKES
FROM CS ONSET TO BEGINNING
EYEBLINK
Generalization vs discrimination
• Generalization is the tendency to respond
to like stimuli the same way.
Generalization gradient
Discrimination training
• The correct stimulus is explicitly paired
with a given reinforcement (explain).
• Or two different responses are paired with
two explicitly different stimuli
Mauk & Ruiz
• The differential condition is two different
ISIs
Eyelid Movement Using Two
Different ISI
Acquisition of Conditioned Eyelid
Closure (two different ISIs)
Latency To Onset of Eyelid Closure
Mauk & Ruiz: Six Different ISI to
Six Different tones
Note the Difference in Behavior of
the Eyelid to Different ISIs
Three Conditioned Eyelid Closures
Elicited by Three Different ISI
Associated Tones
TRACE CONDITIOING
1. Acquisition of conditioned
• What is measured or counted
• Number of blinks across trials for CS alone
• Number of blinks across trials for paired
CS/UCS
• Latency to Onset.
Neural Response
Berger et al
High-Order Conditioning
• One can use the CS as the UCS
CS USED AS A UCS
• Periodically must retrain CR, sound, or the
response will be extinguished
OVER SHADOWING
• The salience of one cue is greater than
that of the other cue.
TEST INDIVIDUAL CUE
TEST INDIVIDUAL CUE, LIGHT
BLOCKING
Test for Sound Group I
TEST GROUP II