Working Memory Model
In 1974, Baddeley and Hitch came up with the Working Memory Model (WMM). This model focuses on how short-term memory (STM) works.
Another model by Atkinson and Shiffrin, called the Multi-Store Model of memory (MSM), was criticised for making STM too simple. The WMM suggests a different idea, saying that STM is made up of three smaller storage parts:
1. Central Executive: This part manages attention and controls information from the two 'slave stores' below.
2. Articulatory-Phonological Loop: This part holds language-based information temporarily. It includes an inner voice process for language (articulatory rehearsal) and a storage space for auditory speech information (phonological store or inner ear).
3. Visuo-Spatial Sketchpad: This part holds visual and spatial information for a short time.
Later on, an additional component called the episodic buffer was added to the Working Memory Model (WMM). This helps the central executive communicate with long-term memory.
The idea of the three-storage STM comes from studies using a 'dual-task technique' where participants do two tasks at the same time. The results of these tasks suggest that different limited-capacity STM stores handle different memory types:
- If one store is used for both tasks, performance is worse than when done separately. For example, saying "the the the" aloud while reading silently uses the articulatory-phonological loop for both tasks, slowing down performance.
- If tasks require different stores, performance is not affected when done simultaneously. For instance, saying "the the the" aloud while doing a reasoning task (requiring attention, like the central executive) or following a moving object with your eyes (using the visuo-spatial sketchpad).
Evaluation of the Working Memory Model:
-Supporting Study- A case study (Shallice and Warrington, 1974) on brain-damaged patient KF supports the WMM's idea that separate short-term stores handle short-term phonological and visual memories.
-Real World Practical Applications- The model has practical applications in understanding and addressing issues related to working memory deficits. It has been used to explain difficulties in various clinical populations, such as individuals with attention disorders, learning disabilities, and neurological conditions.
Generalisability Issues- Laboratory experiments on the WMM may lack real-life relevance (low ecological validity) because tasks like repeating "the the the" might not represent our everyday activities.
Limited Explanatory Power- The model focuses primarily on short-term memory processes and does not provide a comprehensive account of the relationship between working memory and long-term memory. Critics argue that a more integrated model should consider how information is transferred between short-term and long-term memory systems.