Researchers have often tried to determine how much information a person can store until the brain reaches a limit. The ability to process new information and recall details, and just how many items one can process at any given time, has typically been included in this area as well. Capacity of working memory, generally the limited information someone can readily retrieve, includes what used to often be referred to as short-term memory. It is typically important in learning, thinking, and problem solving. There are several theories as to how information is stored by the brain in the short term, and many researchers believe that most people can hold up to seven pieces of information at a time.
Some tests of the capacity of working memory might, for example, involve using shapes and colors that a person is already familiar with. Other experiments can use objects that are unknown to the person. In general, someone who is asked to recall details about something he or she has never seen remembers less about what was shown. There has been disagreement between researchers on testing procedures, but getting information to go into working memory has often been debated by teachers. Information storage is often thought to be most efficient when the brain focuses full attention on the details first.
While many researchers believe people can retain seven details at once, others think it is less than that. The capacity of working memory can be improved by blocking pieces of information into chunks. Comprehension of language and reading is often thought to operate this way. Efficient information processing can also be aided by quickly moving details between short- and long-term memory; psychologists refer to this ability as automaticity.
Capacity of working memory has been modeled by various researchers. The Baddeley and Hitch model, developed in the 1970s, breaks working memory up into different, interacting components, while The Theory of Ericsson and Kintsch covers the ability to group information such as numbers into large chunks. All components of memory, including immediately processed information, are grouped into long-term memory as part of The Theory of Cowan.
Experiments in cognition have been performed to analyze the capacity of working memory. Brain imaging techniques used in neuroscience have sometimes been applied to studying memory as well. Spatial and non-spatial memory processing, information maintenance, and processing of memorized details each seem to be accomplished in certain parts of the prefrontal cortex, as well as throughout other parts of the brain. Many such experiments have sought to find out how the brain processes specific stimuli and what the role of certain areas is in memory management.