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. In 1956, George Armitage Miller wrote his paper on how short-term memory is limited to seven items, plus-or-minus two, 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. Types There are two main approaches to coding information: the physiological approach, and the mental approach. The physiological approach looks at how a stimulus is represented by neurons firing in the brain, while the mental approach looks at how the stimulus is represented in the mind. There are many types of mental encoding that are used, such as visual, elaborative, organizational, acoustic, and semantic. However, this is not an extensive list Visual encoding Visual encoding is the process of converting images and visual sensory information to memory stored in the brain. This means that people can convert the new information that they stored into mental pictures (Harrison, C., Semin, A.,(2009). Psychology. New York p. 222) Visual sensory information is temporarily stored within our iconic memory and working memory before being encoded into permanent long-term storage. Baddeley's model of working memory suggests that visual information is stored in the visuo-spatial sketchpad. The visuo-spatial sketchpad is connected to the central executive, which is a key area of working memory. The amygdala is another complex structure that has an important role in visual encoding. It accepts visual input in addition to input, from other systems, and encodes the positive or negative values of conditioned stimuli. Elaborative encoding Elaborative encoding is the process of actively relating new information to knowledge that is already in memory. Memories are a combination of old and new information, so the nature of any particular memory depends as much on the old