<P> Rehearsal is the process where information is kept in short - term memory by mentally repeating it . When the information is repeated each time, that information is reentered into the short - term memory, thus keeping that information for another 10 to 20 seconds (the average storage time for short - term memory). </P> <P> Chunking is a process by which one can expand his / her ability to remember things in the short term . Chunking is also a process by which a person organizes material into meaningful groups . Although the average person may retain only about four different units in short - term memory, chunking can greatly increase a person's recall capacity . For example, in recalling a phone number, the person could chunk the digits into three groups: first, the area code (such as 123), then a three - digit chunk (456), and, last, a four - digit chunk (7890). This method of remembering phone numbers is far more effective than attempting to remember a string of 10 digits . </P> <P> Practice and the usage of existing information in long - term memory can lead to additional improvements in one's ability to use chunking . In one testing session, an American cross-country runner was able to recall a string of 79 digits after hearing them only once by chunking them into different running times (e.g., the first four numbers were 1518, a three - mile time). </P> <P> It is very difficult to demonstrate the exact capacity of short - term memory (STM) because it will vary depending on the nature of the material to be recalled . There is currently no way of defining the basic unit of information to be stored in the STM store . It is also possible that STM is not the store described by Atkinson and Shiffrin . In that case, the task of defining the task of STM becomes even more difficult . </P>

Where is your short term memory stored in the brain