Working Memory

Working Memory

1. William James 1890 primary memory

   • All quiet Behaviourist agenda
     • 1960's interest: Atkinson and Shiffrin Modal model + others also...
       • sensory stores haptic, echoic and visual, short term stores and LTM. All in a linear model with decay, displacement and interference all active. Input and response unit.
         • Problems presented by KF - good LTM, poor STM: Better visual than echoic
           • Baddeley & Hitch 74 tripartite system CE/AL/VSS: Baddeley 1984 : Articulatory Loop becomes phonological Loop with a store and subvocalisation process: Baddeley 1986: Adopts N and S model of CE being supervisory. Baddeley 1996 abandons storage in favour of attention control system SAS Baddeley 2000 : multimodal episodic buffer to solve binding problem
             • Testing effect of STM load on cognitive tasks - Learning, reasoning and comprehension
               • Dual task paradigm: High STM loads impact on cognition, but no catastrophic failure if STM full, so must be an overspill resource ( central executive)
                 • Model suggest that WM can combine storage and cognitive operations. Supported by Daneman and carpenter who found reading span test showed reading span test was predictive of comprehension, showing that both tasks - memory and comprehension were, at one level, sharing a single resource.
                   • Finding that x 2 auditory tasks and x2 visual tasks are worse than 1 + 1 leads to idea that audio and visual must be separate. Leads to tripartite model.
                 • dual task does affect but a small load of 2/3 items can be carried without impact
             • Logie '95 suggests we have vsual system with a spatial rehearsal loop like auditory subvocalisation
               • Cowan '88 suggests WM is part of LTM because it is improved with better LTM knowledge ( chess players)
                 • Jones points out Binding problem to which Baddeley responds with 'episodic buffer'
             • Phonological loop
               • Begins as articulatory Loop. Baddeley 74 saw evidence for an articulatory loop: phonemic similarity effect : faster speakers : 2 sec rehearsal AL explains articulatory suppression. phonemic similarity reduced and word length effect eliminated in visual presentation so 2 systems at work
                 • 1984 : Fractionates AL into store and subvocalisation: phonemic similarity affects store and word length affects subvocalisation.
                   • Development and cross cultural diffs: children's ability to speak faster increases in line with word span: diff languages diff word span ( 2 sec rule) :
                   • Irrelevant speech harder to ignore than noise - enters the phonological store and disrupts processing. Suppression eliminates effect
                   • Neural basis Vallar and Baddeley '84 study of PV suggest storage and rehearsal diff systems. Paulescu et al PET scans diff locations for rehearsal and store. Broca's area and supramarginal gyrus.
             • Central executive
               • Baddeley 74 idea of it controlling slave stores - but what controls it ?
                 • Central workspace idea early on that it shares storage and cognitive processes. Towse et al '98 challenge - tests on children do not support this idea/ Perhaps fractionated.
                 • Attention: Norman and Shallice '86 Supervisory Attentional System adopted by baddeley '86
                 • Fractionation :Baddeley '96 suggests FOCUS, SWITCHING, ATTENTION +LTM Miyake et al 2000 supports 3 way fractionation, but complicated
                   • Creates Binding Problem
                     • Baddeley 2000 proposes multimodal episodic buffer which has stores from all modalities and coordinates. The CE is purely attentional and episodic buffer is controlled by conscious awareness.
                       • Central Executive
                         • Visuo spatial scratchpad
                           • Visual semantic
                         • Episodic buffer
                           • LTM
                         • Phonological Loop
                           • Language