Lecture 3: Non-associative Learning
Learning, Psychology 3510
Spring, 2015
Professor Delamater
Non-associative Learning
Or, for the most part, changes in responsiveness to a single stimulus
Three Types
1. Habituation
2. Dishabituation
3. Sensitization
Non-associative Learning: Habituation
•
•
•
•
Learning to “tune” out the radio, or the siren, etc
Used to study sensory capacities in human infants, and, more generally,
Simple learning processes in other organisms.
Major headway in understanding the neural mechanisms in memory.
Habituation – Decline in responsiveness to a stimulus with repeated
exposures, but arising from “central” changes.
Non-associative Learning: Habituation
•
•
•
•
Learning to “tune” out the radio, or the siren, or background noise, etc
Used to study sensory capacities in human infants, and, more generally,
Simple learning processes in other organisms.
Major headway in understanding the neural mechanisms in memory.
Habituation – Decline in responsiveness to a stimulus with repeated
exposures, but arising from “central” changes.
Non-associative Learning: Habituation
•
•
•
•
Learning to “tune” out the radio, or the siren, or background noise, etc
Used to study sensory capacities in human infants, and, more generally,
Simple learning processes in other organisms.
Major headway in understanding the neural mechanisms in memory.
Habituation – Decline in responsiveness to a stimulus with repeated
exposures, but arising from “central” changes.
Women asked to rate the
Pleasantness of a specific
Taste stimulus.
Also, the amount of
Salivation was measured.
Steady decreases with repeated
exposures suggests habituation.
Non-associative Learning: Habituation
Habituation – Decline in responsiveness to a stimulus with repeated
exposures, but arising from “central” changes.
How do we know this is due to a “central” change?
Non-associative Learning: Habituation
Habituation – Decline in responsiveness to a stimulus with repeated
exposures, but arising from “central” changes.
Need to rule out sensory adaptation and motor
fatigue (two “peripheral” change mechanisms).
Non-associative Learning: Habituation
Habituation – Decline in responsiveness to a stimulus with repeated
exposures, but arising from “central” changes.
Need to rule out sensory adaptation and motor
fatigue (two “peripheral” change mechanisms).
But notice that Habituation is Stimulus-Specific!!!
This rules out Motor Fatigue as an explanation of the decrease in responding.
But what about Sensory Adaptation???
Non-associative Learning: Dishabituation
Dishabituation – Recovery in responsiveness to an already habituated
stimulus.
Michael Davis:
Studied Startle responding in the rat
Tone
50
45
40
35
30
25
20
15
10
5
0
Test
Light - Tone
1
2
3
4
5
6
7
8
9
10
11
Mean Startle Response
Dishabituation of the Startle
Response in the Rat
Stimulus Presentations ("Trials")
Presenting a Tone stimulus causes the rat to startle.
But repeated presentations of this Tone results in progressively less startle responding.
Non-associative Learning: Dishabituation
Dishabituation – Recovery in responsiveness to an already habituated
stimulus.
Michael Davis:
Studied Startle responding in the rat
Tone
50
45
40
35
30
25
20
15
10
5
0
Test
Light - Tone
1
2
3
4
5
6
7
8
9
10
11
Mean Startle Response
Dishabituation of the Startle
Response in the Rat
Stimulus Presentations ("Trials")
Is this due to Habituation, Sensory Adaptation, or Motor Fatigue?
The Startle response recovers on a test trial when Light is presented just before the Tone.
The Light stimulus dishabituates the rats startle response to Tone.
This rules out sensory adaptation, as well as motor fatigue.
Non-associative Learning: Short vs LongTerm Habituation
Dishabituation – Recovery in responsiveness to an already habituated
stimulus.
Leaton (1976) Experiment:
Studied Startle responding in the rat
FIGURE 2.10
Startle response of rats to a tone presented once a day in Phase 1, every 3 seconds in
Phase 2, and once a day in Phase 3. (Based on “Long-Term Retention of the Habituation of
Lick Suppression and Startle Response Produced by a Single Auditory Stimulus,” by R.N.
Leaton, 1976, Journal of Experimental Psychology: Animal Behavior Processes, 2, pp. 248–
259.)
Tones presented once a day produces lasting long term habituation.
Tones presented every 3 s produces deeper habituation.
But this does not last until the next day – short term habituation (shows spontaneous recovery).
Short ISI leads to good short term habituation, but long ISI leads to good long term habituation.
Non-associative Learning: Sensitization
Sensitization – Increase in responsiveness to a stimulus when the
stimulus is presented in an “arousing” context.
Davis (1974) Experiment:
Studied Startle responding in the rat
FIGURE 2.11
Magnitude of the startle response of rats to successive presentations of a tone with
a background noise of 60 or 80 dB. (Based on “Sensitization of the Rat Startle
Response by Noise,” by M. Davis, 1974, Journal of Comparative and Physiological
Psychology, 87, pp. 571–581.)
Tones presented in a relatively quite environment undergo habituation.
Tones presented in a noisy environment undergoes sensitization.
Non-associative Learning: Sensitization
Sensitization – Increase in responsiveness to a stimulus when the
stimulus is presented in an “arousing” context.
Davis:
Studied Potentiated Startle responding in the rat
Experimental Procedure:
Present Tone and measure startle responding
Present Foot Shock, then Tone and measure startle responding
The Tone produces more startle responding when it follows a Shock
than when presented alone. The shock “potentiates” the startle response to the Tone
probably because it “arouses” the rat.
Non-associative Learning: Sensitization
Habituation & Sensitization processes both can affect responding
at the same time.
Habituation in the human infant
Experimental Procedure:
Present visual stimuli that vary in complexity and measure
Looking time.
Non-associative Learning: Sensitization
Habituation & Sensitization processes both can affect responding
at the same time.
Habituation in the human infant (Bashinski, Werner, & Rudy, 1985)
Experimental Procedure:
Present visual stimuli that vary in complexity and measure
Looking time.
Looking time steadily decreases over trials as the infant habituates to the visual stimulus.
Looking time first increases to the complex stimulus (sensitization) before it decreases
(habituation).
Non-associative Learning: Dual Process
Theory (Groves & Thompson, 1970)
Habituation & Sensitization processes both can affect responding
at the same time.
S-R System:
State System:
Habituation (processing of information from sensory to motor neurons)
Sensitization (general process that can influence many neural pathways)
Habituation should be stimulus specific
Sensitization should be stimulus general because it relies on a general “state” system
Non-associative Learning: Sensitization
and Dishabituation Compared
Dishabituation & Sensitization both increase responding.
Do they have a common underlying substrate, e.g., arousal?
Hypothesis: If they have a common underlying substrate, then whenever one occurs the other
should also occur.
Marcus, Nolen, Rankin, & Carew (1988) Aplysia Study
• Gill Withdrawal Response habituates,
Dishabituates, and sensitizes
• But they have different developmental
onsets
• That means dishabituation can occur
without sensitization, so they must rely
on different underlying substrates.
Non-associative Learning: Sensitization
and Dishabituation Compared
Dishabituation & Sensitization both increase responding.
Do they have a common underlying substrate, e.g., arousal?
Hypothesis: If they have a common underlying substrate, then whenever one occurs the other
should also occur.
Whitlow (1975) Rabbit Study
Trial Type
A–A
B–B
A–B
B–A
Event 1
Tone 1
Tone 2
Tone 1
Tone 2
Event 2
Tone 1
Tone 2
Tone 2
Tone 1
} Same Trials
} Different Trials
• Vasoconstriction measured in response to different tone stimuli
• Less responding to Event 2 on Same than Different trials indicates habituation
Non-associative Learning: Sensitization
and Dishabituation Compared
Dishabituation & Sensitization both increase responding.
Do they have a common underlying substrate, e.g., arousal?
Hypothesis: If they have a common underlying substrate, then whenever one occurs the other
should also occur.
Whitlow (1975) Rabbit Study
Trial Type
A–A
B–B
A–B
B–A
A-x-A
B-x-B
A-x-B
B-x-A
•
•
•
•
Event 1
Tone 1
Tone 2
Tone 1
Tone 2
Tone 1
Tone 2
Tone 1
Tone 2
x
x
x
x
Event 2
Tone 1
Tone 2
Tone 2
Tone 1
Tone 1
Tone 2
Tone 2
Tone 1
} Same Trials
} Different Trials
} Same Trials + distractor
} Different Trials + distractor
Vasoconstriction measured in response to different tone stimuli
Less responding to Event 2 on Same than Different trials indicates habituation
More responding to Event 2 on Same + distractor than Same trials indicates dishabituation
Equal responding to Event 2 on Diff + distractor and Diff trials shows NO sensitization
Non-associative Learning: Sensitization
and Dishabituation Compared
Dishabituation & Sensitization both increase responding.
Do they have a common underlying substrate, e.g., arousal?
Hypothesis: If they have a common underlying substrate, then whenever one occurs the other
should also occur.
Whitlow (1975) Rabbit Study
Trial Type
A–A
B–B
A–B
B–A
A-x-A
B-x-B
A-x-B
B-x-A
Event 1
Tone 1
Tone 2
Tone 1
Tone 2
Tone 1
Tone 2
Tone 1
Tone 2
x
x
x
x
Event 2
Tone 1
Tone 2
Tone 2
Tone 1
Tone 1
Tone 2
Tone 2
Tone 1
} Same Trials
} Different Trials
} Same Trials + distractor
} Different Trials + distractor
• Results: Dishabituation can occur without Sensitization, indicating that
• These two processes must rely on different underlying substrates
Non-associative Learning Involving
Complex “Emotional” Stimuli
Solomon and Corbit (1974): Opponent Process Theory
Two opposing processes combine to produce an overall emotional effect, but one of these
processes (the opponent “b” process) change over time and the other (“a” process) does not.
This leads to a decreased emotional response when stimulus occurs, but a lasting opponent
response when the stimulus is removed.
Initial Exposure to Drug
After Repeated Exposures to Drug