1. Underlying Processes in Classical Conditioning
Theory

2. S-S vs. S-R Models of Conditioning
S-S Learning = Stimulus-Stimulus
The CS becomes directly associated with the US
Therefore, the CS comes to elicit a response that is similar / related to the US
S-R Learning = Stimulus-Response
The CS becomes directly associated with the UR
Therefore, the CS comes to elicit the same response as the UR

3. S-S vs. S-R Models
The research conducted to test whether classical conditioning is based on S-S or S-R learning has found evidence to support both positions (not usually in the same study :)
Currently, there tends to be a heavier emphasis on study of S-S associations

4. S-S Approaches One example is Pavlov’s stimulus-substitution theory
The CS acts as a substitute for the US
A connection forms in the brain between the CS and the US activation sites
When the CS is activated alone following acquisition, it will automatically activate the US site in the brain
Therefore, the CR should be almost identical to the UR (because the connection between UCS and UR in the brain is hardwired)

5. Evidence in support of the stimulus substitution hypothesis
Jenkins & Moore (1973) study:
Autoshaping in pigeons
One group had CS(light)-->US(grain)
Photos showed pigeons trying to “eat” the lit key (open beak and closed eyes) when they pecked
2nd group had CS(light)-->US(water)
Photos showed pigeons trying to “drink” the lit key (closed beak and open eyes) when they pecked

6. Jenkins & Moore (1973) Left = Water Right = Grain

7. Evidence against the stimulus substitution hypothesis
Any study in which the elicited CR is different from the UCR
e.g., when a tone is paired with shock, rats will jump to the UCS (shock), but the CR is typically freezing
e.g., when a light is paired with food, rats will rear to the light (CR) but the UCR is approach to the food dispenser

8. Preparatory Response Model
Kimble’s (1961, 1967) theory proposed that the CR is a response that serves to prepare the organism for the upcoming UCS
e.g., following acquisition of CRs in eyeblink conditioning, the CR eyeblink may actually prepare the person for the upcoming airpuff such that the eye would be partially closed when the airpuff occurs

9. Compensatory-Response Model
The compensatory-response model is one version of preparatory-response theory
In this model of classical conditioning, the compensatory after-effects to a US are what come to be elicited by the CS
Based on the opponent-process theory of emotion / motivation

10. Opponent-Process Theory of Emotion (Solomon & Corbit, 1974)
Emotional events elicit two competing processes:
The primary- or A-process that is immediately elicited by the event
e.g., taking an exam elicits an unpleasant A-state
An opponent- or B-process that is the opposite of the A-process and counteracts it
e.g., the pain during the exam (A-state) creates a pleasant relief response (B-state) following the exam

11. Properties of the A and B processes
A-process
magnitude & duration of the A-state are determined by the stimulus event
magnitude & duration are fixed (no change with experience)
B-process
dynamic; changes with repeated exposure
with repeated exposure the B-state begins earlier, has greater magnitude, & lasts longer
if time passes without exposure, the changes in the B-state reverse
Changes due to repeated exposure depend upon short delays between presentations

12. Underlying Opponent Processes
First few stimulations
After several stimulations

13. Opponent-Process Theory of Emotion
The actual emotional state of the organism is determined by the difference in magnitude between the 2 states:
The A-state minus the B-state = end emotional result
If A-state > B-state, then the emotion experienced will be A-like
If B-state > A-state, then the emotional result will be B-like

14. Resultant Emotional State
First few stimulations
After many stimulations

15. Evidence for a Compensatory-Response Model
Siegel (1972) gave rats repeated injections of Insulin
Insulin’s effects are to reduce the level of glucose in the blood
Tested by giving the rats an injection of saline (instead of insulin)
Measured the CR (change in blood glucose levels)

16. Siegel (1972) Results
There was a strong CR that occurred, but it was an INCREASE in blood glucose levels
(The opposite of Insulin’s direct effect)
CR ≠ UR, and the CR was definitely compensatory

17. More Evidence in Support of the Compensatory-Response Model
Conditioned morphine tolerance (Siegel, Hinson, & Frank, 1978)
Experimental Group: CS (light change & noise reduction) paired with US (injection of morphine) for 9 days
Unpaired Control Group
Placebo Control Group (CS paired with injection of saline)

18. Siegel et al. Results (Conditioned Drug Tolerance)
Test: present CS, inject every rat with morphine, & place each rat on a moderately hot surface
Measure latency to lick their paws
The faster they lick, the quicker they feel the pain

19. Challenges to the Compensatory-Response Model
Eikelboom & Stewart (1982) found that the CR was much like the response to the drug itself (UR) with both opiates like morphine and with stimulants such as cocaine and d-amphetamine.
It has been argued that conditioned tolerance effects could be due to habituation of the direct A-process rather than being due to classical conditioning of the opponent B-process.