PSYC 3210 :: Laboratory Exercise - Classical Conditioning and Autoshaping

Objective

To train a starling so that it will eat from a hopper whenever you operate the hopper, then to approach the hopper when you turn on a cue light.

Introduction

One of the first steps in a behavioral experiment is to train the subject to obtain food or water from a remote-controller hopper or magazine. Eventually we will use the food or water as a reinforcement for performing the correct behavior in an operant discrimination task. This conditioning is called magazine training or autoshaping, and it is a well-studied form of classical conditioning.

As you’ll recall from your reading, classical conditioning involves an association between a neutral stimulus (the conditioned stimulus) and a stimulus with innate value (the unconditioned stimulus). In this exercise, the US is the starling chow in the hopper, and the conditioned response that you are trying to evoke is the starling approaching the hopper. What are the CS and the UR?

Autoshaping also has elements of operant conditioning, because the food acts as a reinforcer for whatever the animal was doing before the hopper came up. We will use this facet of the learning to train the birds to peck a key, and then to peck a series of keys to initiate a song playback and then indicate what category the song belongs to. At first, though, it’s important to avoid reinforcing any particular behavior, because once the animal starts to associate some behavior with getting fed, it will stop engaging in other, exploratory behaviors, and you’ll have a more difficult time later on. For example, if you only operated the hopper when the bird was standing next to it, you’d notice that it would spend more and more time in that part of the cage. Thus, it’s essential in this exercise to vary many parameters of the context when you operate the hopper to avoid “stamping in” problematic behaviors.

The basic procedure is to operate the hopper at random intervals and when the bird is at different places in the cage. Each time you operate the hopper (a trial), you’ll record the amount of time it takes the bird to approach the hopper and eat from it. You will also need to record the distance the bird is from the hopper and any environmental events that could explain sudden changes in behavior (loud noises, sudden movements, etc).

Procedure

Preparation

  1. Assign tasks to each member of the group: timing, data recording, operating the hopper and observing environmental events.
  2. The timer needs to have a phone or other device that can be used to measure intervals with at least second precision.
  3. The data recorder should download the data sheet for this exercise and enter the group members’ names and the subject ID (the number on the metal band around the starling’s leg).
  4. The group member who will operate the experiment needs to connect his or her computer to the controller. First, install the Windows or Mac drivers, then connect your computer to the experiment controller using the provided USB cable. Then navigate with Chrome or Firefox to http://192.168.7.2:8000. Let the instructor know if you have any issues.
  5. Spend a few minutes exploring the interface and how it relates to the apparatus. What do each of the buttons do?

Hopper Training

  1. Once everyone in the group is prepared, raise one of hoppers by clicking one of the long buttons at the bottom of the web interface. The bird may be startled by the loud noise but will eventually investigate the hopper and eat from it. Allow it to eat for several seconds and then turn off the hopper by clicking again on the same button.
  2. Using the provided data sheet, record the distance the bird was from the hopper and the amount of time it took for it to approach and start eating. Note any loud or noticeable events in the room. The hopper will automatically release after 60 seconds to avoid burning out the mechanism; score these trials as NA.
  3. Wait until the bird has moved away from the hopper and then an additional 1-20 seconds before raising the hopper again.
  4. Repeat steps 2–3, randomly varying the amount of time and the location of the animal when you engage the hopper.
  5. The bird has reached criterion when the latency is two seconds or less for 30 consecutive trials. Show the instructor or a TA 10 additional trials.

Cue light training (optional)

If your bird completes hopper training before the end of class, you can attempt to train the animal with a light as a secondary cue. The goal here is to direct the conditioned response towards a manipulandum, which in this case is a port that can detect when the bird pecks at it.

  1. As before, the experiment is organized in trials. In each trial, turn on one of the colored cue lights in the center port for two seconds before raising the hopper. Turn the light off and then release the hopper after the bird has eaten.
  2. Record the latency, but this time between the onset of the light and when the animal approaches the hopper.
  3. Repeats steps 1-2 for 10 trials.
  4. Turn on the cue light, but don’t engage the hopper. If the bird doesn’t appear to respond to the light alone, repeat the training for 10 more trials.

There are some interesting questions you can answer once you’re through with this training. What happens if you use a different color cue? A cue in a different location? Do you notice anything different about the CR to the cue light versus the CR to the hopper alone?

Finishing up

  1. Disconnect the operator’s computer from the controller.
  2. Clean up around the cage
  3. The recorder distributes copies of the data sheet to each member of the group
  4. For next week, each member of the group should prepare a plot of latency as a function of time and speed as a function of time.

What’s next?

Next week you will train the birds to discriminate between songs from different individuals. To perform this task, the birds will need to learn to initiate trials by pecking the response keys, a classic operant behavior. You may have noticed that your bird’s CR to the cue light involved approach to the cue light rather than the hopper. At some point, it will peck the cue and we will immediately reinforce that response. Over the week ahead, your instructor and TAs will finish shaping your starlings for next week’s experiment, using a completely automated procedure.