## The Working Memory Model: An Overview Unlike the traditional view of short-term memory (STM) as a single passive store, the **working memory model** proposes that STM is an **active processor** composed of multiple components working together. Proposed by Baddeley and Hitch (1974), this model emphasizes the dynamic manipulation of information rather than simply holding it briefly. **Central Executive (CE):** This is the "boss" of the system, responsible for: * **Directing attention** to relevant information and tasks. * **Allocating resources** to the slave systems. * **Coordinating cognitive processes** involved in reasoning, problem-solving, and decision making. * **Suppressing irrelevant information** to prevent distractions. The central executive has a **limited capacity** and does not store information itself but manipulates it. **Slave Systems:** These specialized subsystems store and process different types of information: * **Phonological Loop:** Deals with auditory information and language-based materials. It comprises two components: * **Phonological Store:** Holds auditory information (like spoken words) briefly (about 2 seconds). * **Articulatory Control Process:** Refreshes information in the phonological store through **rehearsal** (like mentally repeating a phone number). It also converts visual information into auditory code. * **Visuo-Spatial Sketchpad:** Processes and stores visual and spatial information, like remembering shapes, locations, and mental imagery. It has a limited capacity, and information decays quickly unless actively rehearsed. * **Episodic Buffer (added later by Baddeley):** This component integrates information from the phonological loop, visuo-spatial sketchpad, and long-term memory. It acts as a temporary storage space for integrated information, creating a cohesive representation of an event or episode. **Capacity and Coding:** * **Central Executive:** Limited capacity, not well-defined, and coding is primarily modality-free (not tied to specific sensory modalities). * **Phonological Loop:** Limited capacity (around 7 ± 2 units or what can be rehearsed in 2 seconds). Coding is primarily acoustic. * **Visuo-Spatial Sketchpad:** Limited capacity, possibly separate capacities for visual and spatial information. Coding is primarily visual and spatial. * **Episodic Buffer:** Limited capacity, holding around 4 chunks of information. Coding is multimodal, integrating information from different sources. **Resource Allocation and Dual-Task Performance:** The working memory model explains our ability to perform multiple tasks simultaneously (dual-task performance) depending on: * **Task Similarity:** Tasks requiring the same resources (e.g., listening to music and writing an essay, both using the phonological loop) will interfere with each other more than different tasks (e.g., listening to music and walking). * **Task Difficulty:** Demanding tasks require more resources, leaving fewer for other concurrent tasks. The central executive plays a crucial role in **resource allocation**, deciding how much attention each task receives. However, when demands exceed capacity, performance on one or both tasks will suffer. **Conclusion:** The working memory model offers a comprehensive view of STM as an active and multifaceted system involved in various cognitive tasks. Understanding its components and their limitations provides insights into our cognitive abilities and limitations in everyday life.