1. CS US Pavlov: Stimulus Substitution How does CS end up producing R ?

2. NOTE: SMALLER number means MORE learning
Not Much Learning
Lots O’ Learning
Suppression Ratio:
Typical range between:
0.5 (no learning; equal responses before and during CS)
0 (complete suppression of behavior)

3. 10 5 BP ON CS
SR = (5/(5+10) = 5/15 = 0.33 US 30 10 BP ON CS
SR = (10/(10+30) = 10/40 = 0.25 US

4. CS WHY? US Why is the CR eliminated during Extinction ?
Pavlov: Extinction =
build up of inhibition CS CS
WHY? US R US

5. Spontaneous recovery: Increase in the strength of an extinguished CR after a period of time following the last extinction trial.
Wait
CS-nothing
More CS-nothing CR
Extinction
Trials

6. CS-US
CS-US
CS- CR
Trials
Faster Acquisition after Extinction
Savings: Something about prior conditioning is preserved even after extinction of the CR.

7. Example Suggest that something is still there after extinction.
Put another way:
Extinction is NOT the loss of learning, but rather,
it is additional learning
Example

8. A B X + - R Summation Test Recording A is active A is active
B is active
B is active

9. X A + - B R
Spontaneous Activity
Recording
A is active
B is active

10. T Excitatory - Synapse - Na+ - axon T dendrite Terminal
Action Potential -
Receptor T
Vesicles containing
Neurotransmitter T T
Depolarization
axon
dendrite
Synaptic cleft or gap

11. I - - - - Cl– - Inhibitory Synapse axon dendrite Terminal+
Terminal - -
Cl– - -
Action Potential
Different Gate I
Vesicles contain a
different Neurotransmitter
Different Receptor I I
Hyperpolarization
axon
dendrite

12. Conditioned Inhibition
Excitatory conditioning
Inhibitory conditioning
CS —> US
CS —> US
CS+
CS–
NOT lack of learning, rather,
Learning that US will not occur

13. Establishing a Conditioned Inhibitor
Discrimination Training
A — US
B —
A — US
AB —
(better)
In both cases B becomes a Conditioned Inhibitor;
B predicts that the US will NOT happen

14. No CR tells you… NOTHING
How to know if no learning, or if conditioned inhibition ?
No CR tells you…
NOTHING

15. Summation test: CS– reduces CR produced by a CS+

16. Avoidance
responses ON
CS+ US
Avoidance
responses ON
CS– US

17. BP ON
CS+ US BP ON
CS– US

18. Excitatory conditioning = CS predicts US will occur
Inhibitory conditioning = CS predicts US will NOT occur
Excitatory conditioning ≠ increased behavior
Inhibitory conditioning ≠ decreased behavior
Excitatory conditioning ≠ good US
Inhibitory conditioning ≠ bad US