Читать книгу Animal Behavior for Shelter Veterinarians and Staff - Группа авторов - Страница 91

An example of an interval schedule would be an animal trainer training dogs in a shelter not to bark when someone enters the kennels. During this training the trainer walks by and randomly rewards a quiet dog. The dog could be quiet for 30 seconds or 10 seconds, but on average the dog will get rewarded for being quiet every 30 seconds, thus this results in a variable interval schedule of reinforcement (VI 30 sec).

Trainers often take advantage of intermittent schedules of reinforcement to facilitate the persistence of behavior in dog training programs (Hall 2017). For example, detection dogs are trained to search for a target item, like drugs or explosives, for long periods of time. As soon as the dogs detect the item, they are trained to notify the handler. In other words, detecting the item is a cue to engage in a different behavior (notifying the handler). The dogs are then given reinforcement for correctly notifying their handler about the found item. Because reinforcers are delivered only after the dog finds an item, it can be tricky to train the dog to continue to persist in searching behavior since no reinforcement is delivered during that time. To examine the behavior further, Thrailkil et al. (2016) demonstrated how an intermittent schedule of reinforcement can be used to increase the persistence of behavior in a rat model of detection dog training. In their experiment, rats were trained to pull a chain that served as an analog for search behavior. Successfully pulling the chain resulted in the production of a lever that was analogous to finding a target item. The lever presentation cued a lever press, which was then reinforced with food. Pressing the lever was analogous to notifying the handler about the found item. All rats were first trained to pull the chain on a continuous reinforcement schedule, meaning that each chain pull gave the rats the opportunity to press the lever. Later, for some rats, the schedule of reinforcement was slowly faded to an intermittent schedule so that pulling the chain produced the lever only one‐third of the time. For other rats, the schedule of reinforcement remained continuous such that every chain pull produced the lever. To test how the two groups of rats would behave when reinforcement is no longer available, the researchers stopped providing the lever altogether. The rats that underwent intermittent reinforcement persisted in the chain‐pulling behavior for a much longer period of time than rats that received continuous reinforcement. This is good news for those dogs working in the field—as long as they find the target item every now and then and get reinforcement, their searching behavior should maintain for long durations.