Working memory in schizophrenia: Transient "online" storage versus executive functioning

Working memory has been described as the temporary "online" storage and the subsequent manipulation and retrieval of information. It has been suggeste d that the prefrontal cortex is a primary site of working memory. Schizophr enia patients, who are thought to have prefrontal cortical dysfunction, hav e demonstrated inconsistent deficits on a variety of verbal and spatial wor king memory tests. This has led to questions about how to define and measur e working memory, whether these deficits are distinct to one cognitive doma in, and what role factors such as intelligence and symptoms play in working memory performance. We compared schizophrenia patients to normal compariso n subjects in four separate studies. Based upon the results we recommend th at working memory tests be characterized as either transient "online" stora ge and retrieval tasks (where short-term storage and retrieval of informati on is required) or executive-functioning working memory tasks (where storag e, manipulation, and retrieval of information is required). The importance of clearly identifying which distinct aspects of working memory are assesse d is discussed.