<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> <P> However, capacity of STM can be affected by the following: Influence of long - term memory, Reading aloud, Pronunciation time and Individual differences . </P> <P> Diseases that cause neurodegeneration, such as Alzheimer's disease, can also be a factor in a person's short - term and eventually long - term memory . Damage to certain sections of the brain due to this disease causes a shrinkage in the cerebral cortex which disables the ability to think and recall memories . </P>

Where does the brain store short term memory