PSY 402

1. PSY 402 Theories of Learning Chapter 3 – Nuts and Bolts of Conditioning (Mechanisms of Classical Conditioning)

2. Flavor Aversion Learning • Garcia – rats will not drink water with saccharin if they get ill after drinking. • Significant avoidance occurs after just one trial. • Human food aversions are related to illness (89%). • Even if illness occurs hours later it is linked to the previous meal. • Not cognitive – you can know the food is not to blame and still feel an aversion to it.

3. Factors Affecting Conditioning • Timing – how closely in time are the CS and UCS, and which occurs first. • Novelty of the CS and UCS. • Intensity (strength) of the CS and UCS. • Consistency of the pairing between the CS and UCS. • If one or the other appears alone then conditioning is weakened.

4. Stimulus Presentation Paradigms • Delayed conditioning – the CS onset precedes the UCS onset. • Trace conditioning – the CS starts and ends before the UCS onset. • Simultaneous conditioning – the CS and UCS occur together. • Backward conditioning – the UCS starts and ends before the CS onset. • These paradigms will be on the midterm

5. Massed vs Spaced Trials • Better learning occurs when trials are spaced out over time (spaced), rather than bunched together (massed). • Memory consolidation or rehearsal may be needed between trials. • The ratio between the exposure to the CS and the time in-between is the important factor. • If both are the same duration, learning is weaker.

6. Importance of Novelty • Preexposure to the CS (before it is paired with the UCS) reduces learning. • Called latent inhibition because it inhibits learning of the CS-UCS association. • The same thing happens with preexposure to the US (before it is paired with the CS). • Called the US preexposure effect • Other, more novel stimuli are more likely to become associated with the UCS.

7. Stimulus Intensity (Strength) • The stronger the US (UCS), the faster the learning and the stronger the association. • The stronger the CS, the better the learning. • Salience – how attention-getting the stimulus is in relation to other stimuli in the environment. • The most salient CS becomes associated with the UCS. • An overpowering CS may elicit a response of its own, preventing learning.

8. Pseudo-conditioning • Responses to the CS may occur due to the strength of the UCS, not learning. • Once air has been puffed at the eye, blinking may occur in response to any stimulus that comes next, without any learning. • Sensitization resulting from an intense UCS may cause the response to a CS to be increased, even when there is not greater learning. • A control group lets you tell the difference.

9. Acquired Changes in Response • Habituation – response to a repeated stimulus decreases with non-threat experience. • Sensitization – response to a variety of stimuli increases with a single threat experience. • Examples: • Ingestional neophobia, fear of new food • Rats orient less toward light, startle decreases • Chicks are less frightened by shadows flying overhead with repeated exposure.

10. Factors Affecting Conditioning • Timing – how closely in time are the CS and UCS, and which occurs first. • Novelty of the CS and UCS. • Intensity (strength) of the CS and UCS. • Consistency of the pairing between the CS and UCS. • If one or the other appears alone then conditioning is weakened.

11. Stimulus Presentation Paradigms • Delayed conditioning – the CS onset precedes the UCS onset. • Trace conditioning – the CS starts and ends before the UCS onset. • Simultaneous conditioning – the CS and UCS occur together. • Backward conditioning – the UCS starts and ends before the CS onset. • These paradigms will be on the midterm

12. Massed vs Spaced Trials • Better learning occurs when trials are spaced out over time (spaced), rather than bunched together (massed). • Memory consolidation or rehearsal may be needed between trials. • The ratio between the exposure to the CS and the time in-between is the important factor. • If both are the same duration, learning is weaker.

13. Importance of Novelty • Preexposure to the CS (before it is paired with the UCS) reduces learning. • Called latent inhibition because it inhibits learning of the CS-UCS association. • The same thing happens with preexposure to the US (before it is paired with the CS). • Called the US preexposure effect • Other, more novel stimuli are more likely to become associated with the UCS.

14. Stimulus Intensity (Strength) • The stronger the US (UCS), the faster the learning and the stronger the association. • The stronger the CS, the better the learning. • Salience – how attention-getting the stimulus is in relation to other stimuli in the environment. • The most salient CS becomes associated with the UCS. • An overpowering CS may elicit a response of its own, preventing learning.

15. Pseudo-conditioning • Responses to the CS may occur due to the strength of the UCS, not learning. • Once air has been puffed at the eye, blinking may occur in response to any stimulus that comes next, without any learning. • Sensitization resulting from an intense UCS may cause the response to a CS to be increased, even when there is not greater learning. • A control group lets you tell the difference.

16. Conditioned Inhibition • A CS can signal the presence of a UCS. • This is called excitation, CS+ • A CS that never appears with the UCS signals the absence of the UCS. It becomes an “all clear” signal. • This is called inhibition, CS- • In fear conditioning an excitor produces anxiety, an inhibitor produces relief or safety.

17. Detection of Conditioned Inhibition • Summation test: • Step 1 – Condition two stimuli as CS+ & CS- • Step 2 – Present both together. • Step 3 – Present the CS+ alone, with a neutral stimulus, or with another CS+. • The results of Step 2 should be less than Step 3. • Retardation of Acquisition test – turning a CS- into a CS+ takes longer than creating a CS+ from a neutral stimulus.

18. Producing Conditioned Inhibition • Differential (discriminative) inhibition: • Present two stimuli, one always with the UCS, the other always without the UCS. • Conditioned inhibition procedure: • Present the CS with the UCS sometimes, but pair the CS with another stimulus (X) when the UCS is not present. The CS-X combination will produce inhibition. • CS-X is called a compound CS

19. More Inhibition Procedures • Explicitly unpaired (negative correlation): • The CS and UCS never appear together. • Backward conditioning is a type of negative correlation because the CS always appears after the UCS. • Inhibition of delay – when the CS is lengthy (e.g., a very long tone or light), the CR will occur closer in time to the UCS with practice.

20. Necessary Conditions for Inhibition • The CS must occur without a UCS in a situation where a UCS is possible – when it is otherwise expected. • The CS then becomes a signal of the absence of the UCS. • The CS is irrelevant and no attention is paid to it if there is no relation (contingency) between it and the UCS.

21. Blocking and Unblocking • Blocking studies what happens when there are two CS’s and a single UCS. • When two neutral stimuli are paired with a UCS, one becomes a CS associated with the UCS and the other does not – it is blocked. • The unattended stimulus is blocked because it provides no new information about the UCS. • When it provides info about intensity it is unblocked.

22. Relative Validity • In a situation where differential stimuli vary with the presence of the UCS but a third stimulus does not, blocking occurs (correlated condition). • In a situation where all stimuli appear with the UCS the same amount of time, all three will be conditioned (uncorrelated condition). • There is no blocking of any stimulus.