The working memory model

Who proposed the Working Memory Model (WMM) and what does it explain?

Baddeley and Hitch (1974). It is an explanation of how Short-Term Memory (STM) is organized and functions when we are temporarily storing and manipulating information for complex tasks.

What is the role of the Central Executive (CE)?

It is a supervisory system that monitors incoming data, focuses and divides limited attention, and allocates information to the subsidiary slave systems (phonological loop, visuo-spatial sketchpad). It has no storage capacity.

What is the Phonological Loop (PL) and what are its two parts?

It processes auditory (acoustic) information and preserves word order.

· Phonological Store: Stores the words you hear.

· Articulatory Process: Allows for maintenance rehearsal (repeating words/sounds in a loop). Its capacity is about 2 seconds of speech.

What is the Visuo-Spatial Sketchpad (VSS) and what are its two parts?

It stores and processes visual and spatial information.

· Visual Cache: Stores visual data (what things look like).

· Inner Scribe: Handles spatial relationships and movement.

Its capacity is about 3-4 objects.

Who added the Episodic Buffer (EB) and what is its role?

Baddeley (2000). It is a temporary store that integrates visual, spatial, and verbal information from the other subsystems. It maintains a sense of time sequence (records episodes) and links Working Memory to Long-Term Memory (LTM). Its capacity is about 4 chunks.

How does the case study of patient KF (Shallice and Warrington, 1970) support the WMM?

After a brain injury, KF had poor STM for auditory information (damaged phonological loop) but could process visual information normally (intact visuo-spatial sketchpad). This supports the idea of separate, independent slave systems.

How do dual-task performance studies (Baddeley et al., 1975) support the WMM?

Performance declines when two tasks use the same subsystem (e.g., two visual tasks compete for the VSS), but not when they use different subsystems (e.g., a visual and a verbal task). This shows the VSS and PL are separate.

What is a limitation of using clinical evidence (like patient KF)?

Brain injuries are unique and often affect multiple cognitive areas. It's hard to know if other impairments, not just the specific memory damage, affected the patient's performance.

What is a major limitation regarding the Central Executive (CE)?

Baddeley (2003) himself stated it is the "most important but least understood" component. It is vaguely described as "attention," but its exact role and whether it has sub-components is unclear, making it an unsatisfactory part of the model.