The working memory model

Baddeley + Hitch (1974) - STM multiple stores because:
 - if do dual task performance + both visual tasks, perform less well than if do them separately
 - if do two things at same time where one visual + the other acoustic, no interference. Do  them as well simultaneously than as would do them separately,

Suggests one store for visual processing + separate store for processing sounds. Formed basis of WMM where 'slave systems' organised by central executive (CE).

Function of CE to direct attention to particular tasks, determining at any time how brain's 'resources' allocated to tasks. 'Resources' are 3 slave systems - phonological loop, visuo-spatial sketchpad, episodic buffer.

Data arrive from senses or from LTM. CE limited capacity.

Limited capacity. Deals w/ auditory info + preserves order of info. Baddeley (1986) further subdivided loops into:
 - phonological store which holds words you hear, like inner ear
 - articulatory process used for words heard or seen. Words silently repeated (looped) like inner voice. Form of maintenance rehearsal.

Used when have to plan spatial task. Visuo and/or spatial info is temporarily stored here. Visual info what things look like. Spatial info is physical relationship b/ween things.

Logie (1995) suggested VSS divided into:
 - visual cache, stores info about visual items eg form + colour
 - inner scribes stores arrangement of objects in visual field

Baddeley (2000) added EB b/c realised model needed general store. PL + VSS deal w/ processing + temp storage of specific kinds of info. CE has no storage capacity; nowhere to hold info that relates visual + acoustic info. EB is extra storage system - also has limited capacity.

EB integrates info from CE, PL + VSS. Also maintains sense of time sequencing - essentially recording events (episodes) that are happening. EB sends info to LTM.

Dual task performance - main reason for developing WMM. Baddeley + Hitcg (1976) supported existence of CE. Task 1 occupied CE (particiapnts given a statement 'B is followed by A' + shown 2 letters eg 'AB' + asked to say true or false). Task 2 either articulatory loop (asked to say 'the the the' repeatedly) or involved both CE + AP (saying random digits). Task 1 slower when Task 2 involved both CE + AP. Demonstrates DTP + shows CE 1 of WMM components.

Shallice + Warrington (1970) - KF - ST forgetting of auditory info greater than that of visual stimuli. In addition, auditory problems limited to verbal material eg letters + digits but not meaningful sounds eg phone ringing. Brain damage restricted to PL. 
Trojano + Grossi (1995) - SC - good learning abilitites w/ exception unable to learn to pair words presented out loud. Suggests damage to PL.
Farah et al (1988) - LH - road accident, performed better on spatial tasks than visual imagery. Suggests separate visual + spatial systems.

Central executive - appears to be allocates resources + essentially same as 'attention'. Some psychs feel too vague + doesn't explain anything. Critics argue notion of single CE wrong - probably several components. Eslinger + Damasio (1985) studied EVR - cerebral tumour removed. Performed well on tests requiring reasoning, suggested CE intact; but, poor decision making - suggest CE not fully intact. Account of CE unsatisfactory, fails to explain anything, more complex than represented.

Brain damaged patients - number of problems w/ this evidence - process traumatic - changes behaviour so person performs worse on certain tasks. Also may have other difficulties eg difficulties paying attention -> underperformance on certain tasks.