Working Memory Model Flashcards
what is the working memory model?
-by the early 1970s it was becoming clear that traditional information processing models, suchas the MSM, could not account for some of the findings from memory research
-it was clear that the STM store was far more complex than existing theories could account for
-Baddeley and Hitch (1974) contested the idea that STM was a single and entirely seperate store
-they referred to the case of KF who, while only having a digit span of two, could transfer new information to his LTM, suggesting that though there had been some disruption to STM, other aspects of his STM must have continued to function-there must be several components of STM
the working memory model: actual model
-according to Baddeley and Hitch, working memory is a complex and flexible system comprised of several interacting components
-Central Executive
-Phonological loop- phonological store, articulatory control processes
-Visuo-spatial sketchpad- inner scribe, visual cache
-Episodic buffer
the central executive:
-> is the supervisory system of working memory, itr controls and manages attention, planning, task switching, but has limited capacity
-it can process information from any sensory system (e.g. sight, sound) and coordinates the activity of other components in working memory
-it uses ‘slave systems’ like:
-phonologival loop (for verbal information)
-visuo-spatial sketchpad (for visual/spatial information)
-episodic buffer (for integrating information)
-these free up space for complex, allowing us to do more than one thing at a time, such as listening and watching
-the central executive is the most flexible but hardest to study, since it is less well understood compared to its slaves systems
phonological loop:
-> often called the “inner voice”, temporarily holds verbal information in a speech-based form, it has two parts:
1. phonological store: passively stores sounds
2. articulatory loop: repeats words in your head (subvocal repetition) to keep them active
phonological loop: Baddeley et al. study
Baddeley et al. (1975) Study:
-aim: investigates how word length affects the phonologival loop’s capacity
-method: participants were shown lists of 5 words (either short, single-syllable words or longe, multi-syllabic words) and asked to recall all of them
-findings: short words were recalled better than long words
-conclusion: the phonological loop’s capacity is based on the time taken to say words, not the number of items (about 1.5 seconds) this is known as the word length effect
visuo-spatial sketchpad:
-> is reffered to as the “inner eye”, it temporarily holds visual and spatial information, it has two components:
1. visual cache: passively stores visual data
2. inner scribe: actively rehearses spatial information
-Klauer and Zhao (2004) Study
Brain Imaging Findings:
-the left brain is more active during visual tasks
-the right brain is ore active during spatial tasks (Todd and Marois, 2004)
visuo-spatial sketchpad: Klauer and Zhao Study
Klauer and Zhao (2004) Study:
-aim: tested whether visual and spatial components are distinct
-method: participants completed eother a visual task (remebering Chinese ideographs) or a spatial task (remembering locations of dots) while also doing interference tasks (visual or spatial)
-findings: spatial tasks were disrupted more by spatial interference than visual, visual tasks were disrupted more by visual interference than spatial
episodic buffer:
-> is a general storage system that integrates information from the visuo-spatial sketchpad, phonological loop, central executive and long-term memory
-it was added to the working memeory model by Baddeley in 2000, as the original model couldn’t explain how people remember coherent chunks of information, like prose, better than unrelated words
-combines information across different parts of working memory and from long-term memory
-studies show that people with intact central executive function but amnesia could immediately recall prose but forgot it shortly after. This suggests the e.b. temporarily stored information before it fades
-helps explain why memory for coherent information (e.g., sentences) is better than for random words, it allows information to be structured and processed using both working and long-term memory
Baddeley and Hitch study:
-aim: to test whether short-term memory (STM) has more than one component
-procedure: participants were given a six-digit number (e.g., 863492) to repeat out loud while also completing a reasoning task (e.g., judging sentences like “A follows B- AB” as true or false)
-hypothesis: if STM is limited to simple storage, doing two tasks at once should impair perfomance on the reasoning task
-findings: participants performed well on both tasks, although the reasoning task was slightly lower, errors were minimal
-conclusion: STM involves more than one component, as people can perform multiple tasks simultaneously if they use different parts of memory. Baddeley and Hitch saw STM as a “working memory” that actively processes information, rather than just storing it. They also viewed long-term memory (LTM) as a passive store accessed by STM when needed
-this study helped develop the Working Memory Model
evaluating the working memory model:
-the WMM has been extremely influential and most cognitive psychologists now use the term working ememory in preference to the term STM
-it is a much more plausible model because it explains STM in terms of temporary storage and active processing
-it also incorporates verbal rehearsal as just one optional process within the articulatory loop, instead of being the sole modality and means of transferring information to LTM
-it attempts to explain how memory functions, rather than simply describing the structure of memory
weaknesses of the working memory model:
-the central executive has not been precisley defined: for example, the term “process” is vague, and the central executive may be made up of several sub-components or even be part of a larger component itself in working memory
-this lack of a comprehensive explanation for each component of WMM draws doubts about the accurazy of its depiction of working memory
-Lieberman (1980) critisizes the working memory model as the visuospatial sketchpad (VSS) implies that all spatial information was first visual (they are linked)
-however, Lieberman points out that blind people have ecellent spatial awareness, although they have never had any visual information
-Lieberman argues that the VSS should be seperated into two different components: one visual information and one for spatial
strengths of the working memory model:
-Shallice and Warrington’s study of KF provides support for the WMM because their findings show that KF had very poor STM recall for auditory stimuli but increased STM recall for visual stimuli
-this suggests that the components of memory which process auditory and visual stimuli are seperate (thus, STM is not a single, unified system), as described in the WMM through the phonological loop and VSS
-Studies of dual-task perfomance, where each participant must undertake a visual and verbal task simultaneously, shows decreased perfomance for such tasks and so supports. the idea that the central executive has a very limited processing capacity (as predicted by the WMM) and that the slave systems are in competition with each other for these tasks and resources
more strengths of the working memory model:
-Baddeley et al. (1998) have presented evidence that the phonological loop, for exmaple, plays a key role in the development of reading, and that for children with dyslexia their phonological loop is not working properly
-while the phonological loop seems to be less crucial for fluent adult readers, is still has an important role in helping to comprehend complex text, it also helps in the learning of new vocabulary
-Turner and Engle (1989)
-Neuroscanning evidence, such as that provided by Braver et. al has demonstrated a positive correlation between an increasing cognitive load processed by the central executive (marked by increasing task difficulty) and increasing levels of activation in the prefrontal cortex
-this supports the idea that the central executive hs the role of allocating tasks to slave systems and has a limited processing capacity, as reflected by the increased brain activation levels, thus suggesting that the WMM is accurate in its mechanism of the central executive
Turner and Engle:
1989
-Turner and Engle devised a test to measure the capacity of working memory
-they asked participants to hold a list of words in memory while at the same time working out mental arithmetic problems
-the number of words correctly recalled in a subsequent test was called the ‘working memory span’
-this measure of working memory capcity has been shown in a number of studies to be linked to the ability to carry out various cognitive tasks, such as reading comprehension, reasoning, spatial navigation, spelling, and note taking (Engle et al. 1999)
