Short-term memory and working memory both temporarily store information until retention in long-term memory. When a person works on a task or solves a problem, information enters short-term memory before it moves into working memory. An example of the distinction might involve reading a recipe, where the steps are held in short-term memory. Working memory retains the steps for a limited period of time, which prevents a cook from adding sugar twice.
Both forms of memory store limited amounts of new information for a short period of time. This allows the brain to continuously remove unneeded data to make room for new information, which happens automatically and sometimes on the unconscious level.
Working memory lumps information together to make it easier to recall a few seconds later and retrieve from long-term storage. Most experts believe seven bits of information can be retained in both short-term memory and working memory, which explains why telephone numbers typically contain seven digits. Acronyms also reduce the burden of trying to recall long names or titles by bundling information into manageable chunks.
Some researchers believe working memory uses concentration and focused attention to allow storage of data in short-term memory. They say that this type of memory is less vulnerable to distractions that might occur while learning something new. Part of the theory involves the process of controlling attention via working memory.
Other scientists found very little difference between these two forms of memory, and they believe they are both part of the same mental processes. Working memory might operate alongside short-term memory, such as allowing a person to remember the first words in a sentence while reading the rest of it. Both types represent important tools in language development and reading, and people with learning disabilities might have deficiencies in one or the other.
Once information is processed and manipulated in short-term and working memory, called primary memory, it goes into secondary memory, where it is stored. Long-term memory might deteriorate over time, but this theory also sparks debate among scientists. Some people use tools, such as writing down a phone number, to help imprint it in long-term memory.