Just about everyone has had the experience of going grocery shopping with a small list of purchases in their mind, only to forget one or more of them upon arriving at the store. Similarly, we all have left one room to retrieve something from another room, forgetting what we are after before we have even arrived. The ability to hold information in mind for a few minutes to a few hours is called working memory. It is essential for everything from language learning in children to following a book chapter from beginning to end.
Working memory was first defined by Alan Baddeley and Graham Hitch in 1974. It is a form of memory that may distinguish humans from many other animals (with the exception of several primates). Working memory, commonly referred to as short-term memory, allows a person to hold on to information for a period of time (minutes or perhaps hours) long enough to do something new with the information, like take notes or solve a problem.
A typical situation in which we rely on working memory is watching an informational program on television, like a segment on a news program, and discussing it later with a friend. We may forget about the specific news event later in the week, but for a period of time we “keep it in mind,” thinking about it and perhaps talking about it with others. Each time we share the information with another person or think about it ourselves, we select details that interest us and alter them slightly to keep them interesting to us. Other examples of tasks that require good working memory in adults include taking notes during a lecture or paraphrasing information we hear or read about.
Alan Baddeley elaborated on the original concept of working memory in 1992, noting that unlike other kinds of short-term memory (such as rote repetition), working memory requires us to focus and maintain our attention on the task at hand. To keep our attentional focus, we must be goal-directed, ignoring distractions that might interfere with goal attainment. Baddeley stressed the importance of the “central executive” system for maintaining attentional focus in working memory tasks.
For children, working memory is essential for learning language. Unlike vision, where we can often study an image as long as we need to, everything we hear occurs in time. The speech signal moves very quickly: an average sentence is about 14 seconds long, an average single syllable word lasts only a quarter of a second, and the average consonant sound may last only 1/12 of a second.
We are all made aware of how fleeting the speech signal is when someone is talking to us and we become distracted, which consequently requires us to ask the speaker to repeat what was just said. In that way, speech is like a billboard that appears briefly in our peripheral vision as we travel at 55 miles per hour along a highway. It we are not paying specific attention in that instant to that part of the road, we will miss it, or only retain small bits of the message on the billboard. In a similar way, information we hear leaves us as soon as it arrives. We are not able to hold it in view like a drawing or photograph, or study it like a person’s face, so we must keep the information in our mind.
For some, improving working memory can be as simple as getting more sleepor more exerciseor learning to avoid distractions. For others, whose working memory is weak enough to significantly impact learning, more help may be needed. Fortunately, the brain is a malleable structure and cognitive skills like working memory can be improved by strengthening key learning pathways in the brain (as regular readers of this blog know—working memory is one of four cognitive skills rapidly strengthened by the Fast ForWord program).
The truth is, we live in an exciting time. Scientists are learning more all the time about how cognitive skills like working memory operate. We can look forward to these discoveries yielding more insights and tools that we’ll be able to use to optimize learning throughout our lives.