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PSYC3301: Lab 1
Instrumental conditioning:
Shaping
Schedules of reinforcement and their effects on behaviour
Lab activities include learning quiz 1


Lab one

Required readings:
Instrumental conditioning:
Domjan 2010, 7th edition: Chapter 5: p121-130, Chapter 6: p155-164

Introduction and Objectives:
Although it would be ideal if we could provide each of you with groups of real, live, research animals,
so that you could run real learning research, this is simply not logistically possible or ethically
acceptable given the number of animals it would require. To overcome this problem, you will use a
clever and very realistic piece of software involving a virtual rat to gain a hands-on approach to the
procedures used in learning research.












In your lectures, you learnt about instrumental (also called operant) conditioning (note that operant and
instrumental are used interchangeably). Both in PSYC1020 and PSYC3301, you have heard that an
operant chamber can be used to study instrumental conditioning by providing an animal (in this case, a
rat) with the opportunity to press a lever (aka “bar”), to obtain food. The study of the properties of
instrumental conditioning then involves studying how the frequency of bar pressing changes as a
function of how often bar pressing is reinforced. Changes in bar pressing can then be used as a measure
of classical conditioning (e.g. fear conditioning).

But first, if we want to study instrumental conditioning or classical conditioning using an operant
conditioning chamber, we need a rat that lever presses. Rats are very exploratory animals and
sometimes press the available bar by chance. Applying the principles of instrumental conditioning, you
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could use such ‘chance’ presses to increase the frequency of bar pressing by simply reinforcing each
bar press with a food reward immediately after the rat performs it, but it would take a long time
because such spontaneous presses don’t happen very often. You can greatly increase the speed at which
a rat learns to bar press by using shaping. Via the use of a virtual software computer program, this lab
gives you the opportunity to shape the bar pressing behaviour of a research rat in an operant
conditioning chamber. In other words, using shaping, you will gradually teach the rat an association
between its behaviour (bar press) and a consequence (food delivery).

Consequently, the objectives of today’s lab activities are for you to:
1. Become familiar with one of the most widely used laboratory paradigms in medical and
psychological research: ‘the laboratory rat in an operant chamber’
2. Gain experience in using shaping to train an animal to bar press.
3. Apply, and understand the effects of, a variable ratio schedule of reinforcement on instrumental
conditioned behaviour

Throughout this laboratory, we recommend that you take notes on your discoveries and thoughts in
your lab book, but also on comments, assistance and explanations given by your tutor; During this lab,
you will have the opportunity to undertake a short quiz with multiple choice and short answer questions
that test your knowledge of lab and lecture content. The quiz is highly RECOMMENDED (but not
compulsory), but your score does NOT count towards your course grade. Answering these questions
will allow you to practice the assessment skills needed to pass this course, which include knowledge of
lecture and lab content, but also the ability to apply that knowledge to new situations. Both lecture and
lab content can be the subject of questions in the final exam. You can practice the quiz as many times
as you wish, and it will remain open until the course is finished.

During this lab, you will:
1. Become familiar with the software Sniffy, the virtual rat Pro 2.0
2. Magazine train Sniffy
3. Train Sniffy to bar press
4. Understand how to monitor Sniffy’s performance across training (operant associations window;
cumulative record window)
5. Place Sniffy on a VR25

By the end of this lab, you should be able to:
1. Explain what shaping is, and in particular how it applies the principles of instrumental
conditioning to train a target behaviour
2. Explain what a VR25 is and why you place your laboratory rat on this reinforcement schedule
once you have trained him/her to bar press by describing its pattern of responding under a
schedule of this kind

Lab activity
Please now follow the directions of your tutor who will guide you through today’s lab activities.

























































































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