What exactly is working memory? Working memory is a cognitive system that temporarily stores and manages a limited amount of information. Working memory is often referred to as short-term memory, although short-term memory is considered only one component of the larger mechanism of holding and manipulating information included in working memory. Baddeley noted that working memory is “a brain system that provides temporary storage and manipulation of the information necessary for such complex cognitive tasks as language comprehension, learning, and reasoning” (2003, p. 189).
Working memory is essential because it regulates our attentiveness to tasks and how we manage distractions, apply strategies to our learning experiences, and form long-term memories. Long-term memory (LTM) is the virtually limitless cognitive system that permanently stores, manages, and retrieves information for later use.
According to Baddeley’s model of working memory , the maintenance of information occurs in one of three subcomponents within this system: the visuo-spatial scratchpad , which holds and manages spatial information; the phonological loop , which holds and manages auditory information; and the episodic buffer , which creates representations of the information, aligning new knowledge to previous knowledge, as shown in Figure 3.1 (Baddeley & Hitch, 1974). These systems are suggested to be controlled by the central executive system.
Figure 3.1: Baddeley’s model of working memory
Baddeley and Hitch proposed a three-part model of working memory. The central executive system controls the three subcomponents by filtering all available information.
An illustration of Baddeley’s model of working memory. The central executive, shown at the top, has two-way connections with the visuo-spatial sketchpad, episodic buffer, and phonological loop. The visuo-spatial sketchpad also has a two-way connection with visual semantics, which has a two-way connection with episodic long-term memory. The episodic buffer also has a two-way connection with episodic long-term memory, which has a two-way connection with visual semantics and language. The phonological loop also has a two-way connection with language, which has a two-way connection with episodic long-term memory.
The central executive system regulates the flow of information, filtering out what is unnecessary, to improve information processing (e.g., decision making, reasoning, and knowledge acquisition). The subcomponents are used as the temporary storage place of the information.
It is also important to note as you read about memory development that research in this area is advancing and elaborating. For example, in 1956, during the noted cognitive revolution, George Miller introduced the idea that working memory was limited (Miller, 2012). Through several experiments, he and his colleagues suggested that the “channel capacity” for attending to information was seven (plus or minus two) pieces of information. This suggestion has been foundational over the years in many learning strategies, such as chunking.
However, as research and technology have continued to advance, additional researchers have suggested that this capacity is limited to approximately 2 seconds, noting that when words or chunked information was introduced with gaps of time, the ability to address the elements was limited to a 2-second timeframe, rather than to a certain number of items (Baddeley, 1990). For example, if someone is given a list of numbers, he or she will remember only a 2-second portion of the total sequence.
Further research has indicated the amount of information that we can store might vary from person to person and changes during one’s lifetime, suggesting that information storage could be dependent on the task (Cowan, 2010). Other research has aligned memory recall to the ability to rehearse the information (Baddeley & Hitch, 1974). These findings continue to encourage efforts to better understand how the brain works, how to design training and instruction, and how we can learn more effectively.
The excerpts in this section are from Gathercole and Alloway (2007). These excerpts elaborate on what working memory is, how we use it, its importance in the process of accurate memory development, its limitations, and the effects of deficits in our working memory. Understanding how working memory affects learning enables us to use strategic applications and attention to approach learning more coherently.