1. Classical conditioning
Forging connections between formerly unrelated events

2. background
It all started with Ivan Pavlov and his study of the digestive system
Research based on work with animals
Wildly successful – 1905 Nobel Prize
Studied the automatic connection between food (meat) in the mouth and the flow of digestive juices
UCS (meat in mouth) > UCR (saliva)

3. The big idea
Start with an unconditioned reflex – an automatic connection between a stimulus and a response (meat>saliva)
You can develop new automatic responses by transferring responses from an UCS to an originally neutral stimulus by repetitively pairing them together

4. Let’s say that a different way
An air puff in the eye (UCS) will always make us blink (UCR)
Flashing a red card won’t
But if we repetitively flash the red card, shortly followed by the air puff, eventually,
Just flashing the red card will make us blink !

5. New terms
The initially unremarkable red card is a neutral stimulus (NS)
The air puff is an UCS
The blink after just the puff is a UCR
The red card, once it causes a blink all by itself, is a conditioned stimulus (CS)
The blink that follows just the red card is a conditioned response (CR)

6. definitions
Classical conditioning (CC) – process by which an organism learns a new association between two paired stimuli; one of which was initially neutral the other producing an unconditional reflex
Unconditioned stimuli (UCS) – an event that constantly and automatically elicits an unconditioned response (UCR)

7. More definitions
Unconditioned response (UCR) – an action that an UCS elicits
Conditioned response (CR) – action that Conditioned Stimulus elicits; it does not have to be identical to the UCR

8. perspectives
CC works across species, from the lowly maggot to the most sophisticated human being
In habituation the UCS proved to be meaningless and lost its power over behavior
In CC the initially meaningless CS becomes crucial and works a heavy influence on behavior

9. More perspectives
CC prepares us for significant events by identifying events that commonly predict them
Gives us advance warning of upcoming threats and opportunities
The more unfamiliar the CS or the more powerful the UCS the faster the CR takes

10. Other aspects
The process that establishes or strengthens a CR is called acquisition
A CR can even be a thought

11. Unraveling the connection
Extinction – the decrease or extinguishment of the conditioned response
In CC, extinction takes place when we repeatedly present the CS without the UCS following it

12. The return of the cs>CR connection
Extinction doesn’t erase the CS>CR connection, it inhibits it
Spontaneous recovery – the temporary return of the extinguished response after a delay

13. All together now
First we build the CS>CR connection through acquisition,
Then we unravel it through extinction,
If we then stop presenting the CS for a while, once we resume its use,
The CR will return, but not for long, unless it is again paired with the UCS

14. Extending the connection
The CR can occur even without presentation of the exact CS which formed it, if the new CS is similar enough
Stimulus generalization – the extension or broadening of a CR from the original CS to another, similar stimulus
The more similar the entire setting is, the more likely the new connection will form

15. Narrowing connections
If differing stimuli, although quite similar to the CS, are never, or rarely, followed by the UCS, then the CR will not emerge
Stimulus generalization – differing responses to differing stimuli that have been followed by differing events

16. What factor is key to cc? What causes the connection to form?
Pavlov thought that the most important element in acquisition was how closely the UCS followed the CS.
We call it temporal contiguity or “nearness is good”
After all, the longer the break between the CS and the UCS, the weaker the connection.

17. Is it just timing? The concept of blocking.
If a CS/CR link has been established, pairing a new CS with the old CS will not work.
This is true even if the timing is perfect for the new CS.
So, nearness in time is not enough.

18. The power of prediction
It’s reliability that counts, the CS’ ability to accurately and consistently predict the UCS.
The UCS must be more likely to occur after the CS.

19. The big picture
CC involves visceral reactions involving the sympathetic nervous system – you feel it in your gut.
It prepares us for important challenges and threats.
But it does not tell us what to do.
For how we learn voluntary, planned behaviors we turn to operant conditioning.