Classical conditioning Forging connections between formerly unrelated events

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)

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

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 !

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)

examples  That particular corner at you high school  The torturer’s black shoes  The song from that certain summer that reminds you of …..  Pavlov’s assistants carrying the meat tray  The tone before the shock  The whistling of a V1 “shrieked”  Sexual fetishes

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)

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

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

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

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

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

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

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

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

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

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.

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.

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.

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.