Donald Overton conducted a study as a direct response to Girden and Culler's 1937 experiment. The study tested the effects of sodium pentobarbital on rats' abilities to learn and remember certain taught responses. These rats were randomly assigned to one of two groups – substance administered or no substance administered (the control condition) – and then placed in a simple maze and taught to escape an electrical shock. Overton found that the rats that had been administered 25 mg of sodium pentobarbital could no longer remember the proper escape response when they were later placed in the maze without the drug. However, if these rats were administered sodium pentobarbital once again and placed in the maze, they recalled the escape response they had been taught. Similarly, when Overton taught a rat the escape response under the control condition (no sodium pentobarbital administered), it could not recall that behavior when it was administered the drug and asked to perform later on. Results strongly indicated that rats performed the learned response more efficiently when in the either sodium pentobarbital or control state that they were in when they first learned it. In regard to this idea the study specifically stated "a response learned under the influence of a particular drug will subsequently reoccur (with maximum strength) only when that drug condition is reinstated". In 1969, Hoine, Bremer, and Stern conducted a test with two main parts. The participants were given time to study and just before they were tested they were asked to consume 10 ounces of Vodka. The very next day they did the same thing except some were intoxicated, while others remained sober. The results found that whether the students were sober or intoxicated they did well, but only if the state they were in was the same when they studied and when they were tested. In other words if they were intoxicated while they studied, then they did better taking the test in the same state. If they were sober when they studied then they got their best results while sober. In later years, similar studies confirmed that learning could be state-dependent. In 1971, Terry Devietti and Raymond Larson conducted a similar study in rats, seeing how memory was affected by various levels of electric shock. Their results supported the idea that the rats' ability to remember a learned response was influenced by their state. The phenomenon continued to