title: Maintenance of real objects and their verbal designations in working memory.
abstract: The present study investigated the neural correlates of working memory maintenance for real objects in contrast to their verbal designations. For this purpose we employed a delayed match-to-sample task using functional magnetic resonance imaging. The conjunction of load effects for objects and for words revealed a common bilateral network with main foci in the ventrolateral prefrontal cortex and the intraparietal sulcus. Load effect for objects in comparison to load effect for words revealed stronger activation of bilateral precuneus, which suggests the use of mental imagery of objects and object features. The opposite comparison load words versus load objects showed premotor and auditory areas to be activated in association with phonological rehearsal. The bilateral common activation indicates overlapping codes for real-world objects and their verbal designations. Importantly, there is also a dissociation between maintenance of words and objects, which indicates that phonological rehearsal and mental imagery are employed to different degrees.
authors.affiliation: Section of Experimental Psychopathology, Department of Psychiatry, Centre for Psychosocial Medicine, University of Heidelberg, Voss-Strasse 4, 69115 Heidelberg, Germany. stefan.kaiser@med.uni-heidelberg.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Kaiser
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Kopka
authors.forename: Mirjam
authors.initials: M
authors.lastname: Rentrop
authors.forename: Stephan
authors.initials: S
authors.lastname: Walther
authors.forename: Klaus
authors.initials: K
authors.lastname: Kronmüller
authors.forename: Robert
authors.initials: R
authors.lastname: Olbrich
authors.forename: Matthias
authors.initials: M
authors.lastname: Weisbrod
authors.forename: Christoph
authors.initials: C
authors.lastname: Stippich
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology*; D055815:Young Adult