Human memory is a complex cognitive structure, which can be defined in many ways. One would argue that memory is 1.) The mental function of retaining information about stimuli, event, images, ideas, etc. after the original stimuli is no longer present. 2.) The hypothesized storage system in the mind that holds this information is so retained. A clear distinction is made between different types of memory systems and can be divided into subclasses.
The first model of the human memory was proposed by Atkinson and Shiffrin in 1968. They introduced two different memory systems first, named after their capacity: Short Term Memory and Long Term Memory. Soon after they added a third memory store and called it Sensory Memory. These memory stores are all said to be operating in different ways and are supposedly located in different areas of the brain, thus investigating their features requires different techniques, and yet another one is used to actually establish that there is a difference.
Sensory memory is associated with auditory and visual senses, information that we are incessantly bombarded with enters the human information processing system along different channels ending its journey in either our Iconic Memory - memory that deals with visual information - or our Echoic Memory - memory that records all heard information. Sperling (1960) set up a visual task to measure the Iconic memory; participants had to recall the number of letters they have seen. He presented the participants with 3 rows of 4 letters for 50 milliseconds; they claimed to have seen more letters. Sperling presumed this happened because the visual information has got forgotten before it could have reached the Iconic Memory Store. Information in Iconic Memory degenerates within 0.5 seconds (Sperling, 1960). Treisman (1964) conducted his study on Echoic Memory. Participants were played the same message into both of their ears and asked to...