The different components of the working memory model are well supported by research evidence. For example Bunge et al. (2000) found that the same parts of the brain were active during reading and recalling tasks, but were more active when participants had to perform two attentional tasks at the same time than when these were performed sequentially (evidence for the central executive). However, much of the key evidence for this model comes from the study of brain-damaged individuals, where it is impossible to make `before and after` comparisons, thus limiting the validity of any conclusions drawn. Working memory has also been useful in understanding some of the cognitive changes associated with mental illnesses. For example, Park et al. (1999) found that working memory deficit may be an important indicator in schizophrenia.
There are many strengths and weaknesses of the working memory model. One strength of the model is that KF who was a brain damaged patient who had an impaired STM. His problem was with immediate recall of words presented verbally, but not with visual information. This suggested that he had an impaired articulatory loop, therefore providing evidence of the working memory’s model view of STM.
However, many psychologists have criticised this model – they think that Baddeley and Hitch’s idea of a central executive is simplistic and vague. Their model doesn’t really explain exactly what the central executive is, apart from being involved in attention.
On the other hand, another strength of the model is that Short words are recalled well than long words (the word length effect). This is evidence for the limited capacity of the phonological loop, since more short words can fit in it better than long words.
Another weakness of the working memory model is that the relationship between working memory and long-term memory is not clear. It is not explained how working memory communicates with, draws information from and sends information to the LTM.