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hello
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so uh in uh this particular episode i'm
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gonna talk about
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uh the discovery of pavlovian
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conditioning
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and in particular the role of object
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learning and
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the reason i wanted to uh make this
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a topic for one of these videos is that
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the story of the discovery of pavlovian
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conditioning
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is not correctly told
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in most accounts
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most accounts have a diagram
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kind of like what's in the first slide
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here uh which
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shows uh uh pavlov's dog all hooked up
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to the apparatus
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and uh on the story is that uh pavlov
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rang a bell
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uh before presenting meat powder to dogs
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in this situation
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and lo and behold after a while the dog
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salivated in response to the bell
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and everybody talks about how that
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was pavlov's discovery of
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pavlovian or salivary conditioning
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it turns out as a couple of things
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screwy about this account um
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one is that uh he never rang a bell uh
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so
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we don't need slides for this one so he
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he uh uh that just uh ringing a bell
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before a presentation of meat powder was
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just the story that somebody made up
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in order to explain what salivary
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conditioning was all about
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the other thing that i think is really
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interesting is that
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pavlov really didn't discover salivary
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conditioning
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he had a lot of people working in the
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lab on digestive physiology and
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salivation as part of digestive
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physiology and so they had methods for
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for uh measuring salivation and they
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were interested in studying the salivary
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reflux and they studied the salivary
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reflex under lots of different
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conditions
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and one of the things that allowed
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pavlov to
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make a lot of progress in this line of
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work
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is that he was an expert in survival
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surgery
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so he could uh
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do surgery on the on the dogs so as to
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externalize
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salivary duct so that the saliva that
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was secreted
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would be collected by a tube
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that ran to a beaker and because he
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[Music]
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was an expert in fact he pioneered
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survival surgery so the dogs
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not only survived the surgery but lived
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for
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a long time a couple of years afterwards
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everyone else who tried this kind of
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procedure there was often a lot of
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infection involved and the animals would
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die
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but pablo was really good at controlling
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infection
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and allowing the animals to survive
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which then allowed him to
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test these animals over and over again
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it's a lot of trouble to go through this
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fistula preparation thing and oh if you
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run the same dogs through these
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experiments over and over again they
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started
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salivating even when they were brought
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into the experimental room
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uh this was noticed by everybody in the
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lab by technicians and
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uh students working in the lab and they
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even had a name for it they called it
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psychic secretion and the notion was
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that
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this was a secretion of saliva in
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response to the thought
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the psychology the thought of food
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pavlov himself was really uncomfortable
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with the phrase psychic secretion
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because he didn't think it was
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scientific enough
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that it sounded too much like
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psychic readings or something
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so this phenomena of anticipatory
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salivation was
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well known in a lab for years
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and uh it wasn't that pavlov had to
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discover
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it uh what pavlov discovered
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and his unique contribution in many ways
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uh towards the initiation
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of a long and and highly uh
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productive line of research on this is
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he
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thought about what might be the
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significance of anticipatory salivation
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and
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his answer to that question was that
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anticipatory salivation told us
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something really important
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about how the brain works and in
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particular how do cerebral hemispheres
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work and it wasn't until pavlov
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landed on that particular interpretation
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of the significance of anticipatory
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salivation
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that the lab started to focus
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on uh the study of the so-called psychic
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secretion
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as the primary subject matter for the
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laboratory
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uh this sequence of events where the
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laboratory supervisor
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often is much more
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skillful at interpreting the data that's
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coming out of the lab
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than the students and technicians who
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work in the laboratory
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that sort of thing we will see lots of
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examples of uh
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uh during the course of the semester and
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that's fairly common
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in science so who was the
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one that actually did discovered
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uh did a systematic investigation
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of of a so-called anticipatory
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salivation and what did the
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first experiments on this the next slide
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shows you
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uh who this was this was stefan
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wolfson so i waited stefan wolfson
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doesn't make it into textbooks except
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the ones that i write
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but uh he was actually the
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collaborator in pavlov's lab who did
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some of the really crucial initial
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experiments
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and his job his assignment was
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to determine what are the mechanics of
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salivation
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so he did these experiments in which he
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presented
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various things to dogs and measured how
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much saliva they produced and
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um in one experiment he exposed dogs to
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dry food in number of occasions
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another series of uh trials
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the dogs were presented with sand in the
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mouth
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and another series of experiments it was
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sour water
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and so these were objects that had a
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particular visual
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appearance and uh when they're in their
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mouth
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uh they have uh or sensory features uh
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and they have a certain feel in the
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mouth if you
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if i put dry food in your mouth or if i
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put sand in your mouth you're going to
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salivate
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pretty excessively the same thing is
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true for sour water
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so doing these experiments involved
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taking these
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objects repeatedly testing
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how these object given object elicits
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salivation
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and the thing to keep in mind is that
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these are
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objects that have multiple features one
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of those features is a visual
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feature what it looks like before the
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substance is put into the mouth
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and the other is the or sensory feature
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and
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what wolfson discovered is that
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after you do a number of these kinds of
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trials you can just present the visual
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cue
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by itself you can just show the sand to
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the dog and he
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starts to salivate which means that he's
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he did he doesn't do that initially he
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doesn't
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salivate to the visual features of sand
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at first
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but it does salivate to those visual
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features
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after he's had a number of experiences
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with
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having sand put into seeing the sand and
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having it put in the map
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so this is a form of object learning
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objects are multi-sensory stimuli
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uh i could pick an object here i'll
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get your hair as an object it's a pen
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it has a lot of different features and
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uh
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uh those as your experience with the pen
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uh leads to the linkages among these
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features like one feature
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is that it's solid it's a particular
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shape
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and if you write on it it writes a
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particular color
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those are all separate features and
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because those are all features of the
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object if i turn the pen upside down or
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sideways
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those features kind of travel together
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and that's the nature of objects objects
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have multiple features
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and those features travel together by
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virtue of the fact
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that they all emanate from the same
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object and uh
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wolfson wolfson's experiment is
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particularly important because
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he demonstrated condition salivation
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in the concept context of
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object learning learning to link
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together
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different features of the same object
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now this has a number of really
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important implications
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one of the things that you read about in
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standard accounts of pavlovian
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conditioning
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is that the conditioned stimulus is a
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neutral cue that's initially unrelated
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to the unconditioned stimulus well in
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the object
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learning paradigm uh the condition
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stimulus
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is a feature of the object which
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initially does not elicit the salivary
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response or the response that you're
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interested in
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it's the uh taste of the sand in the
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mouth that causes salivation not what it
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looks like
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before it's put in the mouth so the
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conditioned stimulus
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uh is is not a neutral object it's not
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unrelated to the unconditioned stimulus
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in fact
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it's part of the same object that makes
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up the odd conditions stimulus
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so the notion that pavlovian
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conditioning occurs with neutral
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conditioned stimuli stimulant
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that's that doesn't make sense
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from the standpoint of a careful reading
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of pavlovian conditioning and it doesn't
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make sense
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in light of a lot of more contemporary
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research
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on these phenomena so viewing pavlovian
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conditioning
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as a form of object learning also
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tells us that pavlovian conditioning is
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going to be a pervasive feature
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of how we deal with the environment
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we're constantly dealing with
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objects we're constantly learning about
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objects and all that kind of learning
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involve association
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learning to link together or associate
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different
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features of those objects
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and that makes for pavlovian
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conditioning to
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be a pervasive aspect
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of our experience if we may look at the
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next slide
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okay uh in this slide we summarize the
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the major features of uh
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this object learning and approach
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analysis of pavlovian conditioning
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so uh the general proposition is number
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one
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the un unconditioned stimuli are complex
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objects
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with multiple features and some of these
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elicit responding unconditionally
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whereas
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other features do not initially
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the ineffective features of the us such
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as
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the visual features of sand
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on those initially ineffective features
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come to illicit responding through
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pairings
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with features that do elicit
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responding unconditionally and because
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of this
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csus pairings are a
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natural consequence of how we
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interact with the environment
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which means that outside the laboratory
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conditioned stimuli are not arbitrary
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they're
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not neutral cues
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but they have an inherent pre-existing
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relationship
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with the unconditioned stimulus and
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that enables pavlovian conditioning to
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occur
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in all kinds of situations in our daily
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experience
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we're constantly interacting with
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objects and we're constantly
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learning about objects the iphone is an
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object that has a lot of different
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features and we learn about those
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uh that object by learning what the
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features are and how they're
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related to one another that kind of
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thing occurs with
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you know coffee cups with all kinds of
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objects far less complicated
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than an iphone object learning is a
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pervasive
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aspect of our daily experience which
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means that pavlovian conditioning is
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going to be
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a pervasive feature of our daily
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experience
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and because of that pavlovian
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conditioning has been observed in all
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kinds of situations so the next slide
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provides a partial list of all the uh
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various situations in which pavlovian
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conditioning
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has been investigated and in each of
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these categories there
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are dozens and dozens of experiments of
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course
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digestion is a big topic defensive
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behavior
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drug conditioning is a huge topic
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there's a lot of contemporary interest
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in drug conditioning
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nursing and maternal behavior involve
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lots of
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aspects of pavlovian conditioning
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there's been studies of
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pavlovian conditioning of aggression of
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sexual
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sexual behavior and even the
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conditioning
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of immune reactivity so
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pavlovian conditioning is here there
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and everywhere so anyone who suggests
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that
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pavlovian conditioning is is not of
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great interest
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because it just has to do with uh
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salivary conditioning
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anyone who makes that suggestion is
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really
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pretty far from the mark
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and so we'll show lots of these examples
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uh in
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in the rest of uh rest of the class
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so that's my story for today and uh
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thanks for your attention and look
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forward to seeing you again
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bye bye
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you
