Table 1.

Summary of the similarities and differences among Baddeley’s, Cowan’s, and Hasher and Zacks’ theoretical frameworks of working memory.

Baddeley’s Working Memory Model (2000)	Cowan’s Embedded Processes Model (2005)	Hasher & Zacks’ Theoretical Framework (1988)
The model consists of: (i) the central executive system, (ii) two slave systems: the visuospatial sketchpad and the phonological loop, and (iii) the episodic buffer.	Hierarchically embedded subsets of memory: (i) activated portions of LTM in response to internal and/or external cues (STM) and (ii) a subset of STM that is in the focus of attention.
The central executive delegates attentional control and keeps representations in a rapidly accessible state for cognitive processing.		Inhibitory mechanisms (access, deletion, and restraint) down-regulate activation to achieve goals. WM depends on the efficiency of inhibiting goal-irrelevant information.
The visuospatial sketchpad and the phonological loop are passive, domain-specific structures responsible for retaining visuospatial and verbal information, respectively. The episodic buffer serves (i) as the interface among the two slave systems and LTM, and (ii) as a workspace for integrating currently activated items.	Domain-general representational format instead of specialized buffers.