Stacks Image 70

8. Classical Conditioning

There are other kinds of antecedents that control behaviour. These stimuli tap directly into the biological inheritance of an organism.

In this chapter we explore reflexes and how the study of reflexes can be used to help people deal with a range of everyday issues. Figure 8.1 is a simple observation of a dog drooling whilst looking at a piece of food in someone’s hand.

Is it possible to use this observation as the basis for developing an in-depth scientific investigation of how organisms respond to the environment with genetically controlled predispositions? Doesn’t seem possible, does it? Well, this is precisely the starting point for a huge area of investigation that has brought new insights into a range of applications from the treatment of phobias to behavioural medicine.

Figure 8.2 will help us proceed. It’s easy to imagine a dog salivating (drooling) to a piece of food, but why on earth is she (Lilly) salivating to a toy punch bag? Our starting point in taking a scientific approach is to look at this observation from a layperson’s point of view, someone, that is, who is not familiar with the obstacles associated with mentalism.

Stacks Image 231
Figure 8.1
Stacks Image 87
Figure 8.2

Our layperson might hazard a guess when explaining Lilly’s behaviour and say something like:

The dog was excited because it knew that it was going to be fed soon!

Notice how the explanation for the behaviour refers to some other behaviour on the part of the dog, her ‘knowledge’ about a future event. But, remember, we said earlier that all of the behaviours of an organism being investigated are considered to be ‘dependent’ variables. You can’t select one behaviour and use it to explain another, instead you have to examine how all behaviours emerge out of the context of the observation. This is how you establish functional relations. To do this, a natural scientist, would design experiments to uncover the laws of nature (i.e., the principles of behaviour) being revealed to us.

A Russian physiologist Ivan Pavolv (1927) conducted such experiments. He was doing research on digestion in dogs and for this research he needed to collect saliva from the dogs. He did what anyone would do to produce the saliva, he fed the dogs and the saliva was collected in special test tubes connected to their cheeks. But then he noticed that the dogs were producing as much saliva before they were fed as they did when they were being fed. Intrigued, Pavlov set about exploring this observation.

In truth, simply saying ‘he set about’ doesn’t do justice to what he did. He laid the foundations for how to conduct systematic experimentation on basic learning principles. He was the first to study what is now called Classical Conditioning (also called Pavlovian Conditioning, or Respondent Conditioning).

The procedures that he devised and the results of these procedures are outlined in detail in Movie 8.1.

Pavlov found many stimuli acting as a CS in his experiments, for example, furniture in room, the vessel containing food, and the presence of an attendant who fed the animals:

  • a Food ---> Salivation (US)
  • b White coat ---> Salivation (CS)

What is the distinction between salivation in each situation?
  • a produced by direct stimulation of mouth
  • b produced by distance receptors (Nose, Eyes, Ears)

  • a connected to NUTRITIOUS aspects of stimuli
  • b something about SIGNALING aspects of stimuli

  • a INNATE, pre-wired
  • b arbitrary

The distinction between US and CS is consistent for Salivation but this is not always the case for other reflexes, e.g.:

LIGHT ---> US for the pupil reflex; but normally used as a CS
TOUCH ---> CS for the pupil reflex, but normally used as a US

If there are so many stimuli acting as CSs, how can we study one CS without interference from others? Pavlov showed us how to ‘domesticate’ the CS into a scientific friend to make it more manageable!

Movie 8.1 will help us proceed. It’s easy to imagine a dog salivating (drooling) to a piece of food, but why on earth is she (Lilly) salivating to a toy punch bag? Our starting point in taking a scientific approach is to look at this observation from a layperson’s point of view, someone, that is, who is not familiar with the obstacles associated with mentalism.

Returning to Lilly’s salivation in the presence of the punch bag, now we know that this is a conditioned response. But how does this conclusion compare with the original guess made by our layperson? Remember it was said that:

The dog was excited because it knew that it was going to be fed soon!

At first sight it appears as if the layperson and the scientist are saying the same thing. However, further inspection of this statement reveals an important difference. The first thing to note is that there would be no need for any further investigation if you adopted the analysis offered by the layperson. The salivation arises because the dog ‘knows’ something. End of investigation!
Let’s dissect the layperson’s statement to see how this sort of explanation is really a pseudo-explanation.

1. The dog got excited
2. because
3. it knew
4. that it was going to be fed soon!

As an example of this argument, look again at the picture of the dog before the bell is presented.

Go on, look!

It is not salivating!

No matter how much
you adhere to this notion about the future, the dog will not salivate unless the bell rings. There has to be something in the present to activate the behaviour. Of course, events in the past allowed this to happen. But those events produced a changed dog, and it is a changed dog that responds to the bell.

What’s more, what
you feel as you look at the dog is your feeling, not the dog’s. And this feeling doesn’t happen because of the future. It occurs because of what happened to you in the past and because of what is happening in the present. It is a product of your own conditioning. You might normally refer to this as something called ‘anticipation’.

Since this term describes
your feeling it cannot be used to explain your feeling. The explanation for this feeling called anticipation comes from the way in which a relation was organised between the sound of the bell and the behaviour of the dog. In other words, the explanation for your feeling can be found by looking at the way in which your environment was organised.

Ideally, we should collect information about how an organism’s physiology changes in response to the environment. However, even if we had all of this information it would only constitute a more detailed description of how an organism changes as a function of changes in the environment. Changes that happened inside an organism also require explaining and this is achieved by looking at its evolutionary and environmental history.

Student: That all sounds a bit complicated to me!

Teacher: Not to worry!

At least
you now know to be careful when you think you have an explanation. In fact, it may never have occurred to you that you ‘had constructed an explanation’. You probably thought you were just sharing your feelings with me. The complexities that I revealed may sound like analysis gone mad, but if one makes mistakes with simple behaviours, then you won’t know where to look when you tackle more complicated behaviours.

In Movie 8.2 you will see examples of how mentalism is associated with over-interpretations of the behaviour generated by classical conditioning procedures.

Movie 8.3 contains a summary of some of the issues in this dialogue between the teacher and the student. Importantly, within this presentation there is a video of Lilly responding to a clicker being held in someone’s hands.

The clicker is never clicked, but look at the behaviours and examine the extent to which you find it difficult to suspend your overactive imagination that is responsible for a mentalistic analysis.

A more formal analysis would record basic dimensions of the behaviour (Chpt. 9) and it would draw attention to the interaction of multiple independent variables; for example, the clicker might function as both a CS (notice how she approached and licked the clicker at one point) and as a Discriminative Stimulus (i.e., it is an SD), and where there might also be possible extinction effects (extinction produces variability in operant behaviour).

In fact, the way clickers are used in operant conditioning is that they are paired first with food using a simple pairing procedure and then they are used as conditioned reinforcers by being delivered after a behaviour occurs.

Oftentimes when students are asked to become self-aware with respect to the role their imagination plays in developing explanations, they react negatively as if they are being asked to treat the organism as a black box. This couldn’t be further from the truth. Being self-aware is not something to be frowned upon, it is quite a difficult exercise. In relation to Lilly’s behaviour, it is easy to see yourself, for example, “empathising with her struggle” to figure out what it is she has to do to get a treat”. But, note how that was said. You see yourself empathising! It is your own responses that are confused with Lilly’s. Nevertheless, the analysis of empathy begins just where you begin in your own analysis of how you interpret another organism’s behaviour. We do it all the time and call it ‘mind reading’.

The most basic example in Classical Conditioning is to be found in the statement “
the dog associated the bell with the food”.

But it was Pavlov who associated the bell with the food, where association means ‘to put together’. Having arranged events in time, Pavlov found that the dogs changed in predictable ways. The way in which the association was arranged determined how the dog changed and that is where the explanation for the change is to be found.

To repeat, the dog responded to the association that Pavlov arranged. How it responds depends on both its biology and how the association was arranged.

Movie 8.3 Shows examples of other kinds of reflexes, something that was not known at the time.

In Movie 8.4 you will see some examples of other ways to arrange associations, procedures that were devised to answer a question that Pavlov hadn’t considered. While Pavlov experimented with the delay between the CS and the US, he didn’t investigate the nature of the
contingency between the CS and US. In his experiments each CS produced a US.

The results from studies looking at contingency and contiguity draw attention to the many ways in which the sequencing of events in time change behaviour. This simple statement has been extended further by research that has examined how biological inheritance sets limits on the kinds of changes that can take place.

Some of this research is described in Movie 8.5 in a study on Conditioned Taste Aversion.


Some other principles
Suppose for a moment we have established a CR using a tone of a given loudness, duration, and frequency. How do you know which feature of the CS the animal is responding to?
Pavlov devised transfer tests to answer this question. Here are the steps:
(1) CS-US training
(2) different stimulus presented (i.e., never been paired with the US)
(3) measure response

He found:
a/ The response to new stimulus was similar to the CR produced by the CS
b/ It was smaller in magnitude
c/ The size of this ‘generalisation response’ is
proportional to the similarity of the test stimulus to the CS. In other words, the more similar the physical dimensions of the new stimulus are to the original CS, the more similar the response.

This was an Important finding because it opened the doors to QUANTITATIVE investigation of the perceptual world of animals. By constructing graphs relating the amount of generalised salivation to characteristics of the stimuli used (e.g., 'distance’ from CS) we can map the extent to which an animal 'perceives' stimuli to be the same or different!

What happens if a CS is repeatedly presented without the US? You could guess the outcome using your empathetic skills, or you could do an experiment. The procedure itself is called an Extinction procedure. The basic finding is a steady decrease in the strength of the CR. Note the term ‘steady’. This implies that a graph can be produced to reveal a pattern of change over time and an example is shown in Figure 8.3.
After extinction to the CS, and after a certain amount of time away from the apparatus, the CR will return again when the animal is placed back into the apparatus. This is called Spontaneous Recovery. The important point to note here is that a prediction of what one is likely to observe is now presented as a basic principle of behaviour, and that it has its own term! Again, to the emphasise the point, you don’t derive principles from speculation, but from data collected under controlled conditions.

Finally, two other basic principles to be mentioned here (but there are more) are Overshadowing and Blocking. In overshadowing, one CS is more salient than the other (e.g., high tone v low light). The stronger stimulus elicits a stronger CR than the CR elicited by the weaker stimulus. Blocking is related to this finding. Suppose we take this strong CS with its strong CR and then add a new stimulus to make a compound CS (i.e., a CS containing both stimuli) to elicit the CR. When the compound stimulus is presented we get a CR. However, if you separately test the two stimuli from the compound CS, you’ll find that the CR is stronger for the original stimulus. That is, previous training with it blocks the development of control by the new stimulus.
Figure 8.3

Procedures used in both Classical Conditioning and in the study of Stimulus Control (Chpt. 7) result in behaviour being controlled by environmental stimuli. Movie 8.6 summarises the diifferences between both sets of procedures.


Finally, classical conditioning, as you learnt in Chapter 4, is used to establish conditioned reinforcers.

Pairing a US, such as food with a NS such as verbal praise, leads to the NS becoming a CS, that elicits the same behaviour as the US.

This use of classical conditioning is very common in early intervention programmes for young children with autism, who initially may only respond to the US. When a behaviour is reinforced with a small eatable item, such as a pretzel, the delivery of the pretzel is paired with the words ‘Well done!’.

Eventually the verbal praise ‘Well done!’ functions as a reinforcer on its own with no need for further pretzels.

Additional Video Resources