Shaping: Day 4

As soon as I put Li'l Swanson in the operant box, she went straight to the bar and placed her paws on it, then looked for a reward. I rewarded her the first few times that she placed her paws on the bar, but after the first few minutes I switched to only rewarding her every 3 or 4 times she placed her paws on the bar in the hopes that she would get frustrated and press harder on the bar, my ultimate goal. She started pressing on the bar after she'd been in the box for about 8 minutes, and by the end of the 30 minutes session she was pressing the bar consistently--she had been shaped! Overall, the shaping process went as I expected, based on our class readings. By using "successive approximations" of the desired behavior, I trained Li'l Swanson to press the bar--trying to get her to press the bar from the get-go would have been nearly impossible, but by rewarding behavior in small steps, I was able to accomplish my task.

In the graph above, the x-axis represents time passed, and the y-axis represents lever presses. As you can see, at the beginning of this session with Li'l Swanson, she did not press the bar very often. However, as time went on, her bar presses increased greatly--by the end of the shaping session, she pressed the bar about 67 times.

Shaping: Day 3

Now that Swanson knows that sniffing the bar will earn her one food pellet and is performing this behavior fairly often, I start reinforcing her intermittently for sniffing the bar for a few minutes. While I was reinforcing her intermittently, I was also looking out for the next behavior I want her to perform--placing one or both of her front paws on the bar. After the first 5 minutes or so, Swanson put her hands on the bar, so I rewarded her. After she put her hands on the bar and I rewarded her a few times for that, I stopped rewarding her when she sniffed the bar and only rewarded her when she put one or both paws on the bar. By the end of our 30 minute session, Swanson was consistently placing her paws on the bar, and she even pressed it a few times!

Shaping: Day 2

Because Swanson now knew that turning her head left towards the bar would earn her food and was repeating this behavior, I started rewarding her intermittently for turning her head left so that she would try different behaviors for food. I began to reward Swanson only when she turned far enough left that her nose touched the bar. Again, it took about 15 minutes for her to learn that touching her nose to the bar/sniffing the bar would earn her a food pellet, but learn it she did. She even put a front paw on the bar once or twice on her own, which I rewarded as well. Once I noticed that she was beginning to put her paw on the bar, I ended the session so that we could end on a good note and so we could start the next step in shaping the next day--getting one then both paws on the bar.

Shaping: Day 1

Once Li'l Swanson learned to associate the noise of the food hopper with food, I was able to start shaping her with the end goal of her pressing the lever for a reward. My first step was to train Swanson to turn her head left (towards the bar) when at the food hopper. Getting her to the hopper was easy enough--because of the magazine training, she knew that the hopper was her new food source. Every time she turned her head left when facing the hopper, I rewarded her; every time she turned her head right or backed away, I did not reward her. After about 15 minutes of this, Swanson had learned that turning towards the bar resulted in food. 

Magazine Training: Day 1

This morning, I met with Dr. Trench to put Lil' Swanson in the operant box for the first time. For those of you who don't know, the operant box was created by Dr. Skinner, and is a box with one clear wall, adjacent to which is a wall with a food magazine (or hopper--just a little tray that food pellets are dropped into from outside the box), a light, and a lever. Whenever the lever is pressed, a food pellet drops into the magazine, the light turns on, and there is a small noise. The operator of the operant box can also trigger these events by pressing a button.

Ultimately, my goal is to teach Swanson to press a bar. Before I can begin shaping her to perform that behavior, though, there are a few things I have to do first--namely, magazine train her. When training an animal (or human, I suppose) using operant conditioning, desired behaviors are encouraged by presenting the organism with a reinforcement when that behavior is performed. Reinforcement works best when it is delivered without delay. While I will be using food as a reinforcement, it would be difficult to feed Swanson a pellet from the magazine immediately after she performs the desired behavior (because she may not necessarily realize that a food pellet has been dropped into the magazine, or because it may take her a few seconds to walk over to the magazine to eat her reward). Magazine training allows me to avoid this problem. Magazine training is simply training the organism (in my case, Lil' Swanson) to associate a reward (food pellets) with another stimulus (the noise and the light turning on). This way, Swanson will learn that when she hears a certain noise, there is food waiting for her, and that noise can be made the instant she performs a desired behavior. 

So Dr. Trench and I began the first step-magazine training. Whenever Swanson was facing the food hopper, I pressed the button to make a pellet drop into the hopper (and make a noise and turn the light on). After she ate that one and backed away, still facing the hopper, I pressed the button again. And again. After feeding Swanson about 50 food pellets, she finally got the hang of associating food with the light and noise--even when she wandered away from the food hopper, she'd turn around as soon as she heard the noise of a treat being dropped down into it, then go eat the treat. See the video below to watch this in action :)

Notice how Swanson has learned to associate the sound with food being delivered--even though Swanson is facing away from the food hopper, she knows that there is a pellet waiting for her as soon as she hears the sound, and runs over to eat it. Success! All in all, this process took 19 minutes, and went how I expected based on our class discussions--pairing the food (the primary reinforcer) with the noise and light (conditioned reinforcer) over and over caused Swanson to associate the noise and light with food. 

Day 1: Meeting Swanson

Before I attended my first Psychology of Learning lab, I didn't think too much of rats. They were pretty neutral in my mind--not as cute as mice or rabbits, but definitely cuter than spiders. And armadillos. By the end of lab, however, I was decided--rats are the best. They're friendlier and more curious than rabbits, and way more cuddly than spiders. Their tails weren't even that bad--they're covered in really soft, fine hair--not bad at all! I was able to hold her (without dropping her, getting peed on, or getting scat on...success.) on the first day of lab. It's meant to be. I have named her after the great Ronald "Ron" Ulysses Swanson, because they both love breakfast food and brunettes. She has decided to go by Li'l Swanson (in honor of her favorite miniature horse, Li'l Sebastian), so Li'l Swanson she is.