At this point, it should be pretty clear that conditioning is more complex than you first thought. While the principles are pretty straight-forward, the blend of our past experiences is not. We bring a myriad of conditioning experiences into any given situation, making the task of determining the role of conditioning in our lives fairly complex. For example, as we talked about in class, I intentionally said I would "call on people at random" to answer a question. I did it to evoke a Pavlovian response, which it did. And that response was complex--we all brought into that situation our experiences with being called on in class, being prepared/unprepared/not sure what was expected. There was some fear (What if I don't know THE answer?) mixed with some excitement (I could look brilliant!). Let's look at some extensions of the basic paradigm that will help us understand some of the complexities of Pavlovian conditioning:

Stimulus Generalization. We rarely encounter the exact same situation twice. There's always some change in the environment. Usually, this new environment has some physical resemblance to an environment with which we have some history. The some is the crucial element--the more similar the new environment is to something we already know, the more we will respond in a similar way.

For example, the first time you walked into Principles of Learning and Behavior, you did not have a history with this class, yet you had certain responses to the environment. This was because there was much in common with previous classes you've been in, and you responded similarly to components of the class that were like previous classes (feeling depressed when you saw how much work was required, etc.). Eventually, you will refine your responses to the stimuli associated with this course, but your initial responses are an example of stimulus generalization. So, resemblance is another way that new reflexes can be developed. Like other parts of conditioning, stimulus generalization is adaptive--we don't need to learn everything all over again every time there's some change in the environment.

Stop for a minute and reflect on the term stimulus generalization. The individual shows similar behavior (generalization) to another stimulus that is similar to the original one. Similar stimulus=similar behavior. Also note the difference between stimulus generalization and higher-order conditioning--in higher-order conditioning the spread of effect is because of temporal contiguity, but there is no temporal contiguity with stimulus generalization--the spread of effect occurs because the two stimuli resemble each other in some important way.

Sensory Preconditioning. We oftentimes associate stimuli long before we know anything about them. Then, once we learn something about one of them, we will have a tendency to respond to the other in a similar way. For example, in the laboratory, a tone and light may be repeatedly presented together to a hungry dog. However, neither stimulus is one that will evoke much of a response from the dog, so the pairing produces little responsiveness. Then, though, lets say we repeatedly pair the light with the presentation of food. Eventually, the dog will salivate to the presentation of the light alone, showing Pavlovian conditioning. What will happen if we now present the tone to the dog? Keep in mind that the tone has been paired with light, but at a time when light was trivial to the dog, and never with food. Even though the tone has never been paired with food, the dog will salivate when the tone is presented, showing sensory preconditioning. It's sensory, since it's a relationship between two stimuli (which we detect sensorily), and the relationship between these stimuli occurred prior to (pre) the development of a conditional reflex between light and salivation (conditioning).

Pretty pedantic description, eh? OK, let's make it real. You go to the Refectory for lunch every day. Every day, you see these two guys having lunch together. It's not a big deal, but it's pretty clear they have a good time together and like each other. It's Friday night, not much is happening, so you decide to go to that brother/sister floor party your roommate mentioned. It's not a terribly exciting mixer, so you look for a familiar face, and one of these guys you see at the Refer every day is there. So you go up to him and strike up a conversation, hoping it'll be worth the effort. He immediately starts talking about his collection of Revenge of the Nerds and Porky's movies. He clearly finds anything to do with flattulence extremely funny (although he uses every term but that), and every time he mentions anything about flattulence, he places his right hand under his left armpit and makes this really gross sound and laughs through his nose. Total geek. This guy gives sophomoric a bad name. People are beginning to stare. You wish you were anywhere else but here. You finally escape, find your roommate, and ask, "Who is that guy?" Your roomie says, "Oh, Brad. You haven't run into Brad and his good buddy Travis before?" Before reading any further, click on Blinky and tell us what do you think of Brad's friend Travis, whom you've never met, and what this has to do with Pavlovian conditioning.

Contiguity vs. contingency. Historically, behaviorists (especially those aligned with Skinner) have talked about the basic requirement for conditioning to occur is temporal contiguity--that two events, one environmental and the other behavioral, occur close together (temporal relating to time, contiguity relating to proximity). Others have argued that conditioning requires, or at least is stronger when, there is a causal relationship between the two (one is contingent on the other). The contingent relationship in Pavlovian conditioning is that the stimulus produces the response, and in operant conditioning, that the behavior produces the change in the environment (e.g.-reinforcer). The Skinnerians point to superstitious behavior as demonstration that contiguity is sufficient, and contingency merely assures contiguity.

A little more on reflexes. The study of reflexes has been of central theoretical importance in the development of psychology.

For those interested in some of the historical thinking about reflexes, see the lecture notes, below, of Bob Kentridge of University of Durham in Durham, England. These lecture notes are from his comparative psychology class:

The Reflex from Descartes to Pavlov.

Trial and Error, from the Rise of Thorndike to the Fall of J.B. Watson

Cognitive Models of Associative Learning

What is learned in Classical Conditioning

Also see Taste Aversion Learning.

Some hints in thinking about Pavlovian Conditioning. This is so important it bears repeating:

• While the terms used in a scientific analysis of behavior may seem mystifying at first, the terms are used for a reason and are keys to understanding the underlying processes. Look, for example, at how we broke down the terms stimulus generalization and sensory preconditioning.

• Pavlovian conditioning is fundamentally involved in our motivations to behave in certain ways, and how we feel about events (emotion). In my example of the phonograph, I vividly remembered the song playing, even though the event occurred 40 years ago. In all examples of operant conditioning, look for a Pavlovian component, and notice how it is involved in how we feel about the situation, and how it drives us to action.

Email Tom!

Last modified on December 10, 1998.