Evaluations - A03

• Support for WMM - Cohen et al found brain activity higher in Broca's area (responsible for speech production) when participants completing verbal task. Regions of occipital lobe (responsible for visual processing) were activated when participants completed a visual task. Demonstrates existence of phonological loop and visuospatial sketchpad, thus increasing validity.
• Limitation for WWM - not enough detail of how the CE actually controls the entire WMM system. Study of EVR - after his tumor was removed he performed well on tests that required reasoning suggesting that his CE was still intact however he had poor decision making skills (eg he spent hours deciding what to eat). Suggests that if CE was single unitary stores higher mental processes would either be completely normal or completely damaged, however some processes of CE remained intact (reasoning) while others showed damage (decision making). Therefore reducing CE validity from WMM.
• Support for WMM - research into word length effect, research shows people find it harder to remember list of long words when compared with list of short words as there is limited space for rehearsal. Word length effect disappears if ppts prevented from rehearsal saying 'lala' for example. This because task occupies articulatory process and therefore shorter words no longer have advantage as they cannot be rehearsed. Supports idea that phonological loop has limited capacity.
• Support for WMM - Baddeley and Hitch found that participants could do two different tasks that used two different stores. Found when participants asked to complete verbal task in articulatory loop and separate task in central executive recall not affected. However, when same participants asked to complete similar tasks recall affected on first task. Demonstrates STM has multiple separate stores with limited capacity thus increasing validity of WMM.