WORKING MEMORY MODEL Flashcards
Who proposed the WMM?
Baddeley and Hitch(1974)
why was WMM created?
to replace the STM store of the MSM. STM must be more complex than just being a single unitary store. STM must be an active processor holding different types of information simultaneously while being worked on.
components of the WMM
central executive, phonological loop, visuo spatial sketchpad and episodic buffer.
central executive
the central executive is the head of the model. it controls attention and can code information from any modality. Receives sense information and filters it before passing it to the sub systems or the slave systems. It is limited in capacity working on one type of information at a time.
phonological loop
the PL acts as a temporary storage for holding acoustic information. it has a limited capacity of what can be said in 2 seconds and it can be sub divided into
1. phonological store ( inner ear) - holding words recently heard.
2. articulatory processes ( inner voice ) - holds and silently repeats the words we are trying to speak
visuo spatial sketchpad
processes visually and spatially coded information thought of as the inner eye.
visual cache - passive store of form and colour.
inner scribe - active store holding the relationships between objects in a 3d space.
episodic buffer
added to WWM in 2000 as the model needed a general store to hold and integrate information from the VSS, PL, CE AND LTM.
research evidence for the WMM
- Dual task performance study
- case study
- biological evidence for the existence of the episodic buffer
- evidence for the capacity of the phonological loop.
dual task research - baddeley and gathercole
participant were split into two groups.
- one group was asked to follow a moving spot of light while also at the same time to describe the visual appereance of angles in a letter. this task only included visuo spatial sketchpad and made its capacity full.
- other group was also asked to follow a moving spot of light but they were also asked to recall a verbal information. this task included both phonological loop and visuo spatial sketchpad.
- it was found that aprticipants did better in the second task as it involved separate systems.
research for separate vss and pl
sharrice and wallington investigated the clinical case of KF as he had a brain injury. his STM was only damaged for verbal material ( he could only manage 2 digits on the digit span test) whilst his visual STM remained intact which suggests that the PL and VSS are separate sub systems.
biological existence for the episodic buffer
Prabhakaran Et Al using brain imaging fMRI scans, researchers asked participants to complete the tasks with equal amlunt of verbal and spatial information. in one condition the spatial and verbal information was separate and integrated in the other condition. it was found that there is more activation in the prefrontal cortex when the information is integrated and in the posterior parts when the information is not integrated. this suggests that the episodic buffer exists and is in the pre frontal coertex.
capacity of phonological loop
baddeley did a research where the participants were visually shown word lists and asked to write them down in the same order. one condition had monosyllabic words like : bond, yield etc whereas the other condition had polysyllabic words like : opportunity. it was easier for the participants to recall the ms words than ps which suggests that the capacity of the pl is not the number of distinct iteams but the approximate time taken to say the word. this is called the Word Lenght Effect.
evaluation of wwm
- the cebtral executive has been criticised by other scientists as a vague concept without a full explanation of its function. baddeley accepts that the concept needs development and the episodic buffer is an inclusion for it.
- the MSM sees STM as a passive store whereas the wmm seems more accurate in describing how memory is used as an active processor.
- lab based so highly controlled with higher internal validity.
however it lacks external validity as it lacks mundane realism.
brain imaging studies shows evidence for wmm
brain imaging study showa that different parts of the brain are involved in storing visual information and verbal information. the occipital lobe is responsible for visual information whereas temporal lobe is responsible for verbal information
research into central executive in wmm.
- baddeley discovered that participants found it difficult to randomly generate a list of number while simultaneously pressing letters on a keyboard. this shows that two tasks were competing for the central executive resources and ce is limited in capacity and only perform one kind of activity at a time.
