Encoding (memory) - History

History

Encoding is still relatively new and unexplored but origins of encoding date back to age old philosophers such as Aristotle and Plato. A major figure in the history of encoding is Hermann Ebbinghaus (1850–1909). Ebbinghaus was a pioneer in the field of memory research. Using himself as a subject he studied how we learn and forget information by repeating a list of nonsense syllables to the rhythm of a metronome until they were committed to his memory. These experiments lead him to suggest the learning curve. He used these relatively meaningless words so that prior associations between meaningful words would not influence learning. He found that lists that allowed associations to be made and semantic meaning was apparent were easier to recall. Ebbinghaus’ results paved the way for experimental psychology in memory and other mental processes.

During the 1900s further progress in memory research was made. Ivan Pavlov began research pertaining to classical conditioning. His research demonstrated the ability to create a semantic relationship between two unrelated items. In 1932 Bartlett proposed the idea of mental schemas. This model proposed that whether new information would be encoded was dependent on its consistency with prior knowledge (mental schemas). This model also suggested that information not present at the time of encoding would be added to memory if it was based on schematic knowledge of the world. In this way, encoding was found to be influenced by prior knowledge. With the advance of Gestalt theory, came the realisation that memory for encoded information was often perceived as different than the stimuli that triggered it. In addition it was also influenced by the context that the stimuli were embedded in.

With advances in technology, the field of neuropsychology emerged and with it a biological basis for theories of encoding. In 1949 Hebb looked at the neuroscience aspect of encoding and stated that “neurons that fire together wire together” implying that encoding occurred as connections between neurons were established through repeated use. The 1950s and 60’s saw a shift to the information processing approach to memory based on the invention of computers, followed by the initial suggestion that encoding was the process by which information is entered into memory. At this time George Armitage Miller in 1956 wrote his paper on how our short-term memory is limited to 7 items, plus-or-minus 2 called The Magical Number Seven, Plus or Minus Two. This number was appended when studies done on chunking revealed that seven, plus or minus two could also refer to seven “packets of information”. In 1974, Alan Baddeley and Graham Hitch proposed their model of working memory, which consists of the central executive, visuo-spatial sketchpad, and phonological loop as a method of encoding. In 2000, Baddeley added the episodic buffer. Simultaneously Endel Tulving (1983) proposed the idea of encoding specificity whereby context was again noted as an influence on encoding.