Verbal working memory is a subset of working memory, commonly known as "short term memory." It refers to the amount of verbal information that the brain can hold and manipulate in order to achieve a goal or solve a problem. Verbal working memory involves more than simply the ability to regurgitate information; it also involves the ability to process information and decide which information is needed for a particular task. It was for this reason that British psychologist Alan Braddeley coined the term "working memory" to replace "short term memory" in scientific literature.
Based on brain imaging techniques, researchers have determined that most processes of the verbal memory take place in the left hemisphere of the prefrontal cortex. Most linguistic information is stored and processed in two nearby areas of the left hemispheric cortex: the Broca's area, which controls grammar and syntax, and the Wernike's area, which controls content and comprehension. This assumption is made based on testing adults, as language has not yet become fully localized in children.
One of the simpler forms of this type of memory is known as the phonological loop, in which a few words or phrases are repeated in the mind continuously for a short period of time. A phonological loop may consist of received information or of planned original utterances called subvocal rehearsal. An example of received information might be a person repeating an address or phone number over and over while searching for a piece of paper on which to write it down — the phonological loop does not contain any original information, only information already at hand. Subvocal rehearsal, however, is the process of formulating new phrases before they are spoken. For instance, one might imagine a young man or woman mentally rehearsing words such as, "I love you, but this isn't working out," in preparation for saying them out loud.
Verbal working memory also assists in the highly complex task of reading comprehension. This involves holding linguistic information about a sentence in the mind long enough to understand both that sentence and its relationship to the surrounding sentences. The longer and more complex the written material, the longer individual components must be held in the working memory before being assimilated into a general understanding of the material. This explains why longer sentences are typically more difficult to understand than short ones.
Language acquisition is another task that is aided by this type of memory. It is widely acknowledged that simply memorizing words or phrases in a foreign language is generally not enough to make a person capable of speaking and understanding the language. Verbal memory allows a language learner not only to memorize information, but also to analyze new linguistic content consciously or unconsciously as it is received. From there, the learner is able to apply grammatical concepts he or she has learned in order to produce original utterances.