Extinction: Days 1 & 2

The goal of today's session was to cease Tortellini's behavior of bar pressing. Extinction is done by not reinforcing the rat after it has performed the previously rewarded behavior. On the first day of extinction, Tortellini seemed extremely frustrated. As expected, she kept biting the lever and using more aggression to press it. Within the first minute of not receiving any rewards, she had already pressed the bar about 92 times. At around 8 minutes Tortellini had another extinction burst, where she kept pressing the lever at an intense rate. Her cumulative records indicate spontaneous recovery at about 22 minutes, where she pressed the lever 4 more times. Towards the end of the session she began to wander around the box, often waiting in the corner close to me.

Tortellini's frustration during extinction

Day 1: Extinction Cumulative Records

On the second day of extinction, Tortellini did not press the bar as many times as the first day. It was definitely apparent that she was beginning to understand she was not going to get rewarded anymore, thus there was no point in pressing the lever. Remember that on day 1 of extinction, Tortellini pressed the bar about 92 times within the first minute--today Tortellini pressed the bar about 92 times within the first 14 minutes. This shows progress since her behavior of pressing the bar is declining. Tortellini's cumulative record for day 2 also shows that she did not have an extinction burst or spontaneous recovery after those 14 minutes. On both extinction days, the number of bar presses were recorded every 5 minutes until 30 minutes was reached. 

Day 2: Extinction Cumulative Records

Table showing the number of bar presses per every 5 minutes on days 1 & 2 of extinction