A laboratory report
Presented to Jennifer Gauthier
In Psychology 210
Department of Psychology
St. Francis Xavier University
February 23, 2007
The purpose of this experiment was to test whether training a simulated rat under a Partial Reinforcement Schedule took longer to extinguish than being trained in a Continuous Reinforcement Schedule. The subject involved was a computer based rat. The rat was trained in a Skinner box to bar press under each a continuous reinforcement schedule and a partial reinforcement schedule. Extinction of both schedules was done and times were reported. The hypothesis was that a rat under a partial reinforcement schedule would take longer to extinguish its behaviour rather than the continuous reinforcement schedule extinction. Results were analyzed under the complications of the conditioning of the animal under these schedules.
Studying the behaviours of animals has been a great importance to many psychologists. By studying animal behaviours, researchers can determine what influences them, whether it is their surrounding environment, reinforcements or stimuli. A very famous psychologist, Burrhus Frederic Skinner enjoyed studying animal behaviours. Skinner believed that any response that is followed by a reinforcing stimulus tends to be repeated (Hergenhahn and Olson, 2005). He also says that to modify a behaviour, one merely has to find something that is reinforcing for the animal whose behaviours one wishes to modify (Hergenhahn and Olson, 2005). Skinner explains this in his Skinner box studies. A Skinner box refers to an experimental test chamber that consists of a grid floor, lever, light and food cup (Hergenhahn and Olson, 2005). Mainly used to study operant conditioning, which refers to increasing the rate at which a response occurs (Hergenhahn and Olson, 2005). These studies involve rats and observing the rat in the Skinner box. The rat receives food pellets through the feeder which is accompanied by a clicking noise. Skinner magazine trained the rat which involves training the animal to approach the food cup when it hears the clicking noise and/or seeing the food come out of the food cup. This noise is then associated with the food. After several trials of this, the rat left to bar press by itself and when the rat does bar press, this response is reinforced with food which tends to be repeated. The more times this occurs, the higher the probability the response will occur again.
To shape an animal, the experimenter reinforced rats’ behaviour when it’s close to the feeder and therefore the rat tends to stay close to the feeder because of being reinforced. Shaping occurs when the rat bar presses on its own. This is done by successive approximation which is the response the rat makes is very similar to the response the experimenter wants to reinforce (Hergenhahn and Olson, 2005). These trials occur through acquisition trials. This is the process of gaining new information from one’s observations (Hergenhahn and Olson, 2005).
This rat is under a continuous reinforcement schedule which where the rat is reinforced every time it makes an appropriate behaviour (bar pressing on its own). Partial reinforcement schedule is where the rat only gets reinforced sometimes when it bar presses, and unlike the continuous reinforcement which is all the time. Extinction of the rats’ behaviour plays a large role in which schedule the rat has been trained under. When the rat’s behaviour is extinguished, the rat no longer bar presses to get food because it no longer “believes” the act will produce a reward.
This study is important because the conditioning that occurs during the different schedules is related to how easily the animal extinguishes its behaviour. Time is a factor in this experiment. It is hypothesized during this study that the partial reinforcement...