Working memory model

Introduction to the Working Memory Model (WMM)

In the previous chapter, we looked at the Multi-Store Model (MSM), which described Short-Term Memory (STM) as a single, simple "bucket" for information. However, Baddeley and Hitch (1974) felt this was too simple. They argued that STM isn't just one store, but an active "workspace" where different types of information are processed at the same time.

Imagine your mind is like a busy kitchen. The MSM thought the kitchen only had one table. The Working Memory Model suggests the kitchen actually has different stations: one for chopping (sounds), one for plating (visuals), and a head chef (the boss) coordinating it all!

1. The Central Executive (CE)

The Central Executive is the most important part of the model—think of it as the "Head Chef" or the "Manager" of your memory. Its main job is attentional control.

Key Functions:
• It decides which information is important and what should be ignored.
• It monitors incoming data and allocates it to the "slave systems" (the Phonological Loop and the Visuo-spatial Sketchpad).
• It has a very limited processing capacity—it cannot handle too many things at once.

Real-world example: If you are driving while someone is talking to you, your Central Executive decides whether to focus on the person speaking or the car suddenly braking in front of you.

2. The Phonological Loop (PL)

This component deals with auditory information (sounds) and preserves the order in which information arrives. It is often called the "inner ear."

It is divided into two sub-parts:
• The Phonological Store: This acts as an "inner ear." It holds the words you hear for a very short time (about \( 1.5 \) to \( 2 \) seconds).
• The Articulatory Process: This acts as an "inner voice." It allows for maintenance rehearsal (repeating sounds or words in a loop to keep them in working memory).

Quick Tip: Think of "Phonological" as "Phone"—you use a phone to listen and speak!

3. The Visuo-spatial Sketchpad (VSS)

The Visuo-spatial Sketchpad is your "inner eye." It handles visual information (what things look like) and spatial information (the relationship between objects).

Key Functions:
• Visual: Remembering colors or shapes.
• Spatial: Planning a route or visualizing how to fit a box into a car boot.

Real-world example: If someone asks you how many windows are in your house, you likely "walk" through your house in your mind. That mental image is being processed by your VSS.

4. The Episodic Buffer (EB)

The Episodic Buffer was added to the model later (in \( 2000 \)) because Baddeley realized the model needed a place to integrate all the different types of information. It acts as a "bridge" between the other components and Long-Term Memory.

Key Functions:
• It combines visual, auditory, and spatial information into a single "episode" or story.
• It provides a temporary storage space for integrated information.
• It has a limited capacity of about \( 4 \) chunks of information.

Summary Table of Components

Central Executive: The "Boss" that directs attention. Capacity: Limited.
Phonological Loop: Processes sound/speech. Capacity: \( \approx 2 \) seconds of speech.
Visuo-spatial Sketchpad: Processes images/layout. Capacity: Limited.
Episodic Buffer: Combines info into a "story." Capacity: \( \approx 4 \) chunks.

Evaluating the Working Memory Model (AO3)

When you are asked to evaluate in your exam, you need to look at the strengths and weaknesses of the theory.

Strengths

1. Dual-Task Performance: Research shows that we can easily do two tasks at once if they use different components (e.g., listening to music while drawing). However, if we try to do two tasks that use the same component (e.g., listening to a podcast while reading a book), performance drops. This supports the idea of separate stores.

2. Brain Scan Evidence: Modern brain scans show that different parts of the brain "light up" when we use visual versus verbal memory. This provides biological evidence that the components described by Baddeley and Hitch are real.

Weaknesses

1. The Central Executive is Vague: Many psychologists argue that the "manager" of the system is the most important part but the least understood. It is unclear exactly how it works or how to measure its capacity. Some say it might even be made of several smaller components.

2. Focus on STM: Unlike the Multi-Store Model, the WMM focuses almost entirely on Short-Term Memory. It doesn't explain much about how information is stored long-term or how we forget things over years.

Common Mistakes to Avoid

• Confusing the stores: Don't say the Phonological Loop processes "vision." Remember: Phono = Phone = Sound.

• Rehearsal: Remember that "rehearsal" happens in the Phonological Loop (specifically the Articulatory Process), not in the Central Executive.

• Capacity: Don't assume working memory is huge. All components have a limited capacity. If you try to do too much, the system crashes!

Quick Review: Key Takeaways

• The Working Memory Model is a model of Short-Term Memory only.
• It consists of the Central Executive, Phonological Loop, Visuo-spatial Sketchpad, and Episodic Buffer.
• It is an active process, not a passive store.
• Evidence from dual-task studies supports the idea that these components function independently.

Cross-reference: For more on how these components were tested in a real experiment, see the chapter on Prescribed Studies regarding Darling et al. (2007).