Memory

Since memory and memory formation cannot be observed directly, various models have been put forth by memory researchers in an effort to clearly and simply describe how memory operates. In the early 1900s, psychologists proposed that memory was like a filing cabinet in that everything was categorized neatly and logically. In order to retrieve information, one simply and logically located the correct file folder. Later, as telephone systems were expanded, memory was likened to a telephone operator's switchboard with information coming in from many directions to a central source that sorted the information and decided on the appropriate output. With the development of the digital computer in the 1950s, psychologists began describing memory in terms of a computer model and focused on how the mind and memory might process information like computers do. This model has been highly influential, and since the 1950s researchers using this model have focused on the input and sequencing of information processing.