The Central Executive
An Overview of the Central Executive Component of Working Memory
The central executive component of working memory Opens in new window is responsible for focusing, dividing and switching attention. It provides the overall regulation and control of the working memory system and coordinates activity between all of the components.
The central executive, which resembles an attentional system, is the component of working memory that has overall attentional control of the working memory system. It was originally described as:
- having some capacity for storage;
- having the possibility of interfacing with long-term memory; and
- allocating resources between the components of working memory by focusing, dividing and switching attention.
The current view of the central executive has changed somewhat.
- First, the central executive is now not regarded as having any capacity for storage, rather, it is only responsible for the control and allocation of attention (Baddeley, 2000, 2007).
- Secondly, the link between the various working memory components Opens in new window and long-term memory Opens in new window is now via a new component known as the episodic buffer, which is discussed fully here Opens in new window.
Therefore, the core role of the central executive in the revised working memory model Opens in new window is in allocating attention within the working memory system, and this is done via focusing, dividing and switching attention.
Baddeley (1996) identified the following as the main functions of the central executive:
- switching of retrieval plans;
- timesharing in dual-task studies;
- selective attention to certain stimuli while ignoring others;
- temporary activation of long-term memory.
Smith and Jonides (1999) produced a somewhat similar list:
- switching attention between tasks;
- planning sub-tasks to achieve some goal;
- selective attention and inhibition;
- updating and checking the contents of working memory;
- coding representations in working memory for time and place of appearance.
Baddeley (2007) argues that there may be separate subcomponents for focusing and dividing attention, but he considers the evidence for a separate component for the switching of attention to be limited at present.
When the model of working memory was first presented (Baddeley & Hitch, 1974) little detail was given about the central executive.
Baddeley (1986) fleshed out the central executive by adopting the model put forward by Norman and Shallice (1986) of a supervisory attentional system (SAS). The SAS was responsible for intervening to direct behavior when new thought and planning was required.
In other words, this attentional system came into play when it was not possible to rely on well-learned patterns of responding. New ideas, new strategies and new plans to deal with new situations required a more demanding degree of attentional control, and this was provided by the SAS (Shallice, 1990).
Therefore, the central executive provides the higher levels of executive control that are required for carrying out novel tasks requiring new behavior or new approaches.
Box X-1 provides an example to illustrate how central executive resources may be used in novel situations.
| Box X-1 Using executive resources when things go wrong |
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| Think about driving to work using a well-known route on a day when nothing unusual happens. This probably does not require much in the way of central executive resources to focus, divide or switch attention. The route is familiar, driving is a routine process and nothing untoward occurs during the journey. However, imagine that, on a particular day, the usual route is blocked because of a burst water pipe. In this circumstance, the central executive must intervene to inhibit the well-learned behavior (i.e. following the familiar route) and work out a new plan that achieves the same goal of reaching the desired destination. Central executive resources may also be required to change the plan if other upsets occur such as traffic jams, to monitor progress, to check that the goal is being reached, and focus attention on negotiating an unfamiliar route. Note that satellite navigation systems remove much of the central executive burden from such tasks, which probably accounts for their popularity! |
Baddeley (1986) described the SAS as potential framework for the central executive because the job it does is very similar to his conceptualization of the role of the central executive.
Exeutive processes are likely to be strongly dependent upon frontal lobe functioning (Kane & Engle, 2002). For example, there is a large body of evidence from patients with frontal lobe damage showing that they often have difficulties with inhibiting well-learned patterns of behavior and arriving at new ways of solving problems Opens in new window.
They become trapped in repetitive cycles of well-learned behavior (known as perseveration) and lack the flexibility to change their behavior when novel situations arise. Baddeley refers to these general difficulties as the dysexecutive syndrome.
Therefore, it is increasingly helpful to view the central executive of working memory as a broad attentional control space. This type of system is likely to resemble very closely what many authors mean when they refer to executive functions Opens in new window.
If we take a current definition of executive functions, ‘processes that control and regulate thought and action’ (Friedman, Miyake, Corley, Young, DeFries & Hewitt, 2006: 172), it becomes clear that the concepts of ‘central executive’ on the one hand, and ‘executive functions’ on the other, are very similar both in practical and theoretical terms.
Other Components of Working Memory:
- Adapted from:
- Working Memory and Academic Learning: Assessment and Intervention. A book by Milton J. Dehn.
- The Development of Working Memory in Children, by Lucy Henry
- Cognitive Psychology: A Student's Handbook, by Michael W. Eysenck, Mark T. Keane
