Extinction

My partner and I decided we would do extinction over two days, and we started extinction on training day 13. Extinction is extinguishing a shaped behavior a organism has learned.  This is done by simply not reinforcing any behavior whatsoever.

The first day of extinction was pretty predictable.  Right away Lil Sebastian went straight to the lever and started pressing it.  She pressed it 18 times before stopping, then wandered around, and then going back to it.  She didn't check the hopper for a pellet until 2 minutes and 20 seconds had passed.  After this, Lil Sebastian definitely was performing an extinction burst. After 5 minutes had passed, Lil Sebastian had lever pressed 142 times, with no reinforcement and only checked the hopper about 3 times.  The number of lever presses slowly decreased every 5 minutes after that, and Lil Sebastian's erratic behavior increased. This was displayed by long periods of her completely focusing on the lever trying to get food, and pressing it many times, then she would seem to give up.  When she wasn't focusing on the lever, she would spend long periods wandering around, rearing up on back legs a lot more than usual, and sniffing or cleaning. Below is a video of her behavior when focusing on the lever.

Here is another video of her typical behavior during extinction while not focusing on the lever.

 

Below is the cumulative record for extinction day 1.

(Extinction Day 1)

Lil Sebastian did display some emotional behavior by jumping up on the wall for a brief period and touching the ceiling of the box with her nose.  This had not happened before. At the end of the first day of extinction, Lil Sebastian had pressed the lever 301 times, and the number of lever presses for every 5 minutes can be seen at the end of this post.

The second day of extinction was much of the same behavior as before.  We did not observe spontaneous recovery because Lil Sebastian was pressing the bar just as much as she was at the end of the previous extinction day.  She was much less active this day, and instead of moving around the box a lot like the day before, she would sit in the middle of the box and sniff or clean often.  She also spent a significant amount of time sniffing and chewing on the floor in the front left corner, which has been a common behavior throughout training.  She displayed another emotional behavior also. She climbed up on the wall of the box in the front right corner 3 times in a row and was able to stay on the wall for up to 20 seconds one time.  Below is a video of this behavior.

Below is the cumulative record for extinction day 2

(Extinction Day 2)

At the end of the second day of extinction, Lil Sebastian had lever pressed only 67 times, which was a huge decrease from the day before.  Below is a table showing the number of lever presses for every 5 minutes for each extinction day.