In this experiment we explore the effects of extinction on the subject. In the previous exercises, the subject received a food pellet each time he pressed the bar. However, in this experiment the operant chamber is modified so that no food pellets are delivered, regardless of the bar pressure that might occur. Additionally, the pellet dispenser will also be muted so that there is no feeder sound that accompanies pressing the bar. Therefore, the primary reinforcement (food) and secondary reinforcement (magazine sound) are removed. For these experiments, the independent variable is reinforcement schedule and the dependent variable is extinction rate. Reinforcement schedule refers to the schedule on which the reinforcer is provided, which in this case is never the case, and extinction rate refers to the time required for an operant response to extinguish after the reinforcer is no longer provided. We considered that extinction was reached when the subject did not press the bar more than twice over a period of 5 minutes, as shown by the cumulative.