A comment on the functional localization of the phonological storage subsystem of working memory

Working memory, as defined by Baddeley and Hitch, is an interactive set of cognitive processes responsible for holding information online and available for analysis. Part of that system is a specialized subsystem devoted to maintaining verbal information; the verbal "slave" subsystem has as a core component a phonological store. For many years, the anatomical locus of the phonological store has been thought to be in the supramarginal and angular gyri of the speech dominant hemisphere, and functional neuroimaging studies provide broad support for this localization. However, a finer grained analysis of published experiments reveals two possible foci for the phonological store within the parietal lobe, neither of which has a pattern of functional activation that is fully consistent with the Baddeley and Hitch model. The purpose of the present paper is to review several studies relevant to the question of the localization of the phonological store and to suggest possible reasons the results are discrepant.