State-dependent memory or state-dependent learning is the phenomenon through which memory retrieval is most efficient when an individual is in the same state of consciousness as they were when the memory was formed. Unlike context-dependent memory, which involves an individual’s external environment and conditions, state-dependent memory applies methods of study memory in children the individual’s internal conditions.
In 1937, at the University of Illinois, Edward Girden and Elmer Culler conducted an experiment on conditioned responses in dogs under the influence of the drug curare. Following this discovery, other researchers looked into the effect of different states of being on the ability to learn and remember responses or information. In 1964, 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. 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 be studied more than thirty years later. The results of each of these studies points to the existence of a state-dependent memory phenomenon. Further research on the subject continues to be carried out today in order to discover further implications of state-dependent memory or other situations in which state-dependent memory might take place. At its most basic, state-dependent memory is the product of the strengthening of a particular synaptic pathway in the brain. A neural synapse is the space between brain cells, or neurons, that allows chemical signals to be passed from one neuron to another.