Executive Functioning

Models and Conceptual Frameworks of EF

[Page 803]Numerous conceptual models of EF have been developed, although no single model has been uniformly accepted. Some models focus on specific executive domains, some on the development of EF, and still others on statistical approaches or clinical views of EF. A few well-known and commonly utilized models are presented here.

The WM model is a widely studied and well-validated multicomponent theoretical framework that highlights the importance of WM in innumerable cognitive processes. The four components of the WM model include the central executive and its three subsidiary and interactive systems: the phonological loop, visuospatial sketchpad, and episodic buffer. The central executive is conceptualized as a limited-attention system, and its functions include selective attention, attention switching, coordination of multiple concurrent activities, and information retrieval from the long-term memory. The visuospatial sketchpad and phonological loop serve as temporary storage systems for visual and auditory material, respectively. The episodic buffer functions to temporarily store information from the phonological loop, visuospatial sketchpad, and/or long-term memory and integrates this information into an episodic event. It is thought that smell and taste information may also be integrated into the episodic buffer. Although its broadness and simplicity may be considered strengths, this model ignores other aspects of EF, such as goal setting and planning.

The supervisory attentional system model is another widely accepted conceptualization of EF. Central to this model is the role of attention in behavioral actions. The supervisory attentional system model proposes two processes for facilitating automatic actions (those actions that do not require any deliberate attention) and nonautomatic actions, such as planning and decision-making, which do require deliberate actions. Actions that require attention usually do not have any preformed behavioral programs that can be called on to complete the task. Thus, the supervisory attentional system provides the additional attentional resources that are required to carry out novel tasks. This theoretical model is important because it accounts for the crucial role of attentional control in automatic and nonautomatic behaviors.

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