Friday, September 28, 2012

Training Session Two: Shaping Tessa

Goal
To shape Tessa the Rat until she forms an observable association between the act of pressing the bar in the Operant Box and the receipt of reinforcement in the food magazine. Shaping is the process of reinforcing successive approximations of the desired behavior until the organism is performing the desired response. 

Procedure
Food deprivation was continued to encourage Tessa to seek reinforcement in the Operant Box. At the time of training, Tessa weighed approximately 205 grams which was over her target weight of 202 grams. Training began at 3:00 PM in Operant Box 3 of the Learning Laboratory. Successive approximations of bar-pressing behavior were reinforced. First, Tessa was reinforced for turning or showing interest in the bar. Next, she was reinforced for moving towards the bar. Rearing behaviors were reinforced near the bar, and touching the bar was instantly reinforced. Variants of behavior resembling the target, but not leading to proper shaping, were not reinforced. For example, rearing behavior away from the bar were not reinforced; likewise, interest in the underside of the bar was not reinforced. The training session continued for 21:59, consisting of 134 manual reinforcements and 59 bar-presses.

Results
Tessa developed a strong association between the action of bar-pressing and the receipt of reinforcement. She was reinforced for multiple behaviors, but the final half of the training session was focused only on bar-pressing behaviors. Tessa responded to these reinforcements, and she was able to maintain steady bar-pressing behavior for nearly four minutes (see graph below).

Cumulative Record for Shaping

Discussion
Tessa's various forms of behavior have both positive and negative effects on the process of shaping. Because she produced a wide array of behaviors, it was not difficult to begin reinforcing the behaviors which resembled bar-pressing. However, once she developed an understanding of the contingency between bar-pressing and reinforcement, she continued to display a wide variety of other behaviors. These include rearing behaviors throughout the cage, interest in the lights above the food magazine and bar, and interest in the front of the cage and floor of the cage. Tessa received manual reinforcement when she lingered too long on one side of the cage. Rearing behaviors were reinforced after Tessa returned to bar level; thus, she was reinforced to stay at the bottom of the box instead of rearing or jumping towards the top. These reinforcements encouraged Tessa to return to the food magazine, which reminded her to engage in the bar-pressing activity.

Training day 2 began at 3:00 PM on September 21st, 2012.

Wednesday, September 26, 2012

Training Session One: Magazine Training Tessa


Goal: 
To magazine train (develop an association between the food hopper/magazine and the delivery of reinforcement in the Operant Box) Tessa the rat. My goal is to condition Tessa to consistently approach the food hopper after hearing the sound of the pellet dropping into the hopper and seeing the light in the box flash on/off.

Procedure:
My rat was deprived to approximately 87% of her original body weight before beginning training. On the training day, Tessa weighed approximately 200 grams, only one gram below her target weight. Training sessions are scheduled to begin at 3:00 PM each day, but may be delayed to 3:30 PM on Thursdays due to scheduling conflicts. On the first day of training, I worked with Dr. Trench to magazine train Tessa. I used the manual reinforcement trigger to deliver a pellet to the food magazine. Once Tessa ate the pellet, I immediately delivered another reinforcement. Reinforcements were delivered consistently for the duration of the training session. Magazine training was performed for 21 minutes, consisting of 69 manual reinforcements and 28 bar-press reinforcements. Shaping was roughly performed during this period to teach Tessa to associate bar-presses and the delivery of reinforcement.

Results:
Tessa consistently returned to the food magazine whenever reinforcement was delivered. She developed a strong association between the sound of pellet deliver, the flickering of the light, and delivery of reinforcement in the food magazine. She was also able to develop a slight association between the bar-pressing behavior and reinforcement.

Discussion:
Tessa displayed a wide variety of behaviors which allowed for some shaping to occur during the magazine training session. Consistent reinforcement delivery was important in maintaining Tessa's attention on the food magazine. The session was ended prematurely when Tessa appeared to be satiated. This occurred after the successful delivery of 69 manual reinforcements, as well as an astounding 28 bar-presses.

Magazine training of Tessa resembles magazine training as discussed in lecture. I found it easiest to reinforce Tessa immediately after receiving a reinforcement, and this seemed to encourage her to spend time around the magazine. Whenever she would travel away from the magazine, it was simple to get her to return: all I had to do was deliver another reinforcement. Soon, she was associating the sound of the food hopper with the delivery of reinforcement.

The shaping procedure will be further discussed in the discussion of Training Session Two.
  
Training Session One was performed on September 19th at 3:00 PM.  

Friday, September 21, 2012

Sniffy the Virtual Rat: magazine training and shaping

Before beginning training with my real rat, Tessa, I was assigned the task of magazine training and shaping Sniffy the Virtual Rat. Sniffy is part of a computer program which simulates the real-world operant box environment, featuring a rat with variable behaviors, a bar which releases a pellet of virtual food into the food hopper when pressed, an indication light, and a water supply. Through this exercise, I was able to understand the characteristics of operant conditioning. This will allow me to correct any attentional or reinforcement errors on my behalf before attempting to train Tessa in the actual operant box.


Goal #1: To magazine train Sniffy the Virtual Rat in order for him to develop an association between the sound/bar and the reinforcement of virtual pellets in the virtual food hopper (magazine).

Procedure:
It took approximately 18 minutes to magazine train Sniffy. During the first three minutes of training, I allowed Sniffy to explore the cage while delivering reinforcement whenever he approached the hopper. The rate of reinforcement was increased as Sniffy approached the hopper. Repeated reinforcements were delivered to increase the association between sound/bar and reinforcement. Progress in building this association was displayed on a graph in the software, which allowed me to better estimate when and how to deliver reinforcement to Sniffy. Sniffy began to press the bar on his own after developing a 50% association between the sound/bar and reinforcement. The final ten minutes of training are characterized by a very high rate of reinforcement. Sniffy was reinforced almost immediately after receiving the previous reinforcement. This restricted him from wandering away from the food hopper, and the rate of association acquisition was increased.

Magazine Training Cumulative Record: Vertical dashes represent reinforcement delivered by the operator. Each region of the graph represents a five-minute period. "CRF Press Bar" indicates the beginning of Shaping. 

Goal #2: To shape sniffy to press the bar through the use of reinforcement. Shaping is achieved by reinforcing successive approximations of the bar-pressing behavior.

Procedure:
It took 55 minutes to successfully shape the bar-pressing behavior in my virtual rat. I began shaping by rewarding any rearing behaviors performed near the back of the cage. I initially rewarded Sniffy for sitting up and scratching his nose, but that did not lead to an increase in rearing behavior. Sniffy began pressing the bar after about five minutes of shaping. I continued to reinforce any rearing behaviors while tracking Sniffy's progress in building an association between bar pressing and reinforcement. I continued on an FR1 schedule of rearing behavior reinforcement until Sniffy began pushing the bar at least four times in a row. At this point, I observed Sniffy's behavior after reinforcement and reinforced rearing behavior on an FR3 schedule. Sniffy achieved a rate of about 20 bar-presses per five-minute period after 22 minutes of shaping. At this point, I allowed Sniffy to reinforce his own behavior by allowing the program to run on its own. Sniffy continued to press the bar at a rate of around 25 bar-presses per five-minute period for the final 33 minutes of shaping. I administered reinforcement whenever Sniffy wandered away from the magazine. This allowed the program to run a little quicker because bar-pressing behavior was more likely once Sniffy returned to the hopper for reinforcement.

Shaping Cumulative Record: Dashes on the top of the graph represent reinforcements administered by the operator. Dashes on the sloping line represent bar-presses by Sniffy. Click to enlarge. 

Sniffy was placed on a variable ratio schedule following shaping.

Monday, September 17, 2012

Tessa's last snack and food deprivation progress

Tessa enjoys her last snack before the beginning of food deprivation in preparation for magazine training and shaping. 

Tessa loves her Cheerios - I used them to reward her after a successful handling session for two days in a row. She tends to hide her rat pellets under the sawdust when fed, but she immediately nibbles down any other snack! Since this video, Tessa has been deprived of food and reached her target weight of 203 grams in only four days! I will begin training Tessa on Wednesday. By the way, Tessa is now eating chocolate daily (chocolate sucrose pellets are used in our laboratory during training).

The current stats for Tessa's weight loss are below:

Target Weight = 203 Grams (87% Body Weight)

Date Weight (grams) Food Given (grams)
09/12/12 233 2.9
09/13/12 220 3.6
09/14/12 213.4 5.1
09/15/12 208 4.1
09/16/12 203 10
09/17/12 206 6

Friday, September 14, 2012

Early Handling Experiences with Tessa

Since meeting Tessa the Rat in lab last week, I have spent more than an hour handling and playing with her. She was extremely skittish around me from the beginning. I'm the tallest person in my class, so I was worried she would be a little more nervous around me than other students. On Thursday, I handled her for about five minutes before she finally calmed down. She loves to burrow between my elbow and torso, so I've found that to be an effective strategy in calming her down quickly. On Friday, I let her do that from the start and she calmed down almost instantly. She was pretty comfortable around me, and I figured out that she was more likely to cling to me when I took her away from her cage. When she is near the cage, she will try to squirm out of my arms and jump back in the cage; if I bring her to the other side of the room (even if she is near the classroom holding cage) she will calm down more quickly. She did bit me a few times on Friday, though, but I never put her down in response (I don't want to reinforce such behavior).

Earlier this week, I started feeding Tessa Cheerios after she calmed down during handling. She bit me a few times while trying to get her out of the cage, but that behavior stopped after I washed my hands. I am happy to say Tessa has gotten used to me over the past few days of handling! Now, she regularly calms down after under a minute of handling if I am sure to let her explore her surroundings. Dannele handled her for me recently and said she was very calm and easy-to-handle.

Wednesday, September 12, 2012

Meeting Tessa!

The Rat
This week, Dr. Trench allowed me to choose my rat from a pool of around twenty identical Long-Evans rats. All of these rats are housed in the same room, allowing them to keep in touch with their sisters. I chose one rat from a cage of two - out of the couple, I chose the more timid/shy rat. I named her Tessa after a nervous, clumsy, anxious character in one of my favorite novels. Unfortunately, rats have yet to develop their own internet (like ants), so it was nice to know Tessa wouldn't be lonely when I took her away from her sister! Tessa shares a spot on the shelf right next to her old roommate, Hazel.

Before encountering the rats this week, I was honestly a victim of the negative portrayal of the species in popular media. While I understand their importance in research, I never expected to train a rat during my undergraduate career. Honestly, these rats defy all of the stereotypes to which I previously subscribed: they are clean (as Dr. Trench assured the class) and carry no diseases; they are more adorable than the rats depicted in my favorite childhood movies (ex: Lady and the Tramp); and, they are much easier to handle than any gerbil or rabbit I've owned as pets. 

My first experience with Tessa was a bit unnerving because she was so frightened of me. I was able to pick her up a few times during the lab period, but her anxiety was indomitable. Tessa clasped to my forearm after first picking her up, and her heart was racing for the entire experience. I tried a few strategies to calm her down: covering her eyes, letting her burrow between my elbow and torso, and petting her - unfortunately, I had to grab her by the tail when she tried to jump from my arm back into her cage. No harm done, though, and I suspect Tessa will adjust to my handling style quickly (as I will adjust my handling style to keep her calm).

I was thrilled to have the chance to interact with my new trainee, Tessa, during the first week of lab! The experience changed my perceptions of rats (at least the Long-Evans sisters), and my studies for class clarified the importance of rats in psychological research. I am excited to see what I can teach Tessa - as well as what she can teach me - during the next couple of months!