Input of Information
Short-term memory, which is one of three types of memory, holds a limited amount of information for a few seconds and is the step before long-term memory. According to the Georgia Tech College of Computing, short-term memory gets its information from one of three types of sensory memories: iconic memory, which receives input from visual stimuli; echoic memory, which receives input from auditory stimuli; and haptic memory, which receives input from tactile stimuli. For the data to transfer from sensory memory to short-term memory, the person must be focusing attention on the particular stimuli. This selective attention was exhibited in Colin Cherry's cocktail party problem: when at a cocktail party, people filter out other conversations to focus on the conversation that interests them, according to Barry Arons of MIT.
Capacity
Once the information reaches short-term memory, it is held for a brief period of time. George Miller proposed in his 1956 article, "The Magical Number Seven, Plus or Minus Two," that short-term memory can hold seven items at a time, plus or minus two; an example is a phone number without the area code. People can increase short-term memory capacity by using a memory technique called chunking, that is, grouping information together in a meaningful way. Ericsson and colleagues, in their article "Acquisition of a Memory Skill," documented an All-American runner who increased his short-term memory capacity to 79 items by grouping the numbers together as running times; when he was given words instead of digits, he no longer had the increased memory capacity. The Georgia Tech experts add that the time frame for short-term memory is 200 ms; after that time, short-term memory no longer holds the information.
Retention
To retain the information from short-term memory, the brain must consolidate it into a long-term memory. According to an article in Scientific American, short-term memories are processed by the hippocampus and are then distributed to the neocortex, where the memory becomes permanent. When the person is sleeping, the rate of consolidation increases. When there is damage to the medial temporal lobe, the part of the brain where the hippocampus is located, new memories cannot be formed.
