What scientific method is used to study the process of formation of a conditioned reflex?

The conditioned reflex became possible to investigate using the experimental method. For the first time, a scientist and doctor named Pavlov was engaged in this. His task was to investigate how a living organism reacts to the sight of food in front of it. In practice, he used dogs in which he performed an operation – he removed the opening from the stomach. The animals were shown food and they reacted by increasing the amount of gastric juice. Determining the amount of juice became possible thanks to fistulas (holes) in the stomachs of dogs.