3.4 WMM

Working Memory Model Overview

• Developed by Baddeley & Hitch (1974)
  • Suggested a more complex model of Short-Term Memory (STM) rather than just a temporary store.
  • Introduced the concept of Working Memory (WM) with a structure that holds various pieces of information simultaneously.

Components of Working Memory

Central Executive (CE)

• Function:
  • Most crucial component of the model
  • Monitors and coordinates the operations of other subsystems (visuospatial sketchpad and phonological loop) and connects them to Long-Term Memory (LTM).
  • Responsible for deciding which information to attend to.
  • Controls attentional processes rather than functioning as a memory store.
• Example of Function:
  • Conflict situations (e.g., driving while talking) illustrate its role in managing attention.

Phonological Loop (PL)

• Function:
  • Deals with spoken and written material.
  • Comprises two parts:
  1. Phonological Store:
     • Acts like an inner ear that holds information in speech form for 1-2 seconds.
     • Spoken words enter directly; written words need conversion into articulatory code.
  2. Articulatory Control Process:
     • Acts as an inner voice for rehearsal
     • Repeats information to keep it active in working memory, e.g., remembering a telephone number.
• Key Point:
  • Converts written material into articulatory code for storage.

Visuospatial Sketchpad (VSS)

• Function:
  • Manages visual and spatial information, described as an inner eye.
  • Helps track relationships between items and our position relative to the environment.
• Tasks:
  • Engages visual information (e.g., layout of your house) and supports dual processing of visual and verbal information simultaneously.
• Limitation:
  • Performing two visual tasks simultaneously reduces performance due to interference.

Episodic Buffer (EB)

• Added in 2000:
  • Serves as a temporary store that integrates information from CE, PL, VSS, and LTM.
  • Plays a role in synthesizing information from different sources.

Key Studies Supporting WMM

Landry & Bartling Study

• Aim:
  • Investigated the effects of multi-tasking on working memory when both tasks engage the phonological loop.
• Procedure:
  • Participants memorized strings of letters while simultaneously repeating "1" and "2" (multi-tasking group vs single task group).
• Findings:
  • Multi-tasking group had a recall accuracy of 45%, while single-task group averaged 76%.
• Conclusion:
  • Multi-tasking harms working memory, particularly when tasks compete for the same system.

The KF Case Study

• Details:
  • Individual suffered brain damage affecting verbal information but not visual memory, implying separable components in memory (VSS and PL).

Neuroimaging Studies

• Tried to discover distinct neural correlates for PL and VSS.
• Evidence suggests:
  • Phonological tasks activate left hemisphere language areas.
  • Visuospatial tasks activate right posterior regions (parietal cortex).
• Controversy:
  • Results are complex and not consistent; the overall processes seem to involve interconnected neural circuits rather than isolated brain areas.

Strengths of Working Memory Model

• Acceptance of multi-component aspects of short-term memory.
• Better explanatory power for various cognitive tasks, such as reading, navigation, and problem-solving.
• Supported by empirical evidence showing the limited capacity of different memory systems.

Limitations of Working Memory Model

• Critiques by Lieberman:
  • Suggests that VSS may combine visual and spatial info incorrectly; blind individuals display spatial awareness without visual input.
• Unclear function and capacity of the Central Executive.
• Limited scope as it does not encompass sensory memory (SM) or long-term memory (LTM).
• Lacks explanation of processing ability changes through practice or time.