title: Working memory effects on semantic processing: priming differences in pars orbitalis.
abstract: Both working memory (WM) and controlled (attention-mediated) semantic processing functions have been thought to operate as limited capacity systems, but the possible link between these processes has not been investigated. We found that increased WM load attenuated semantic priming (i.e., reduced the response time advantage for semantically primed relative to unprimed items) and changed fMRI signal intensities in brain regions usually associated with both WM (dorsolateral prefrontal cortex) and controlled semantic retrieval (inferior frontal gyrus [IFG], pars orbitalis). fMRI signal changes in dorsolateral prefrontal cortex were negatively correlated with signal changes in pars orbitalis. The findings suggest that controlled semantic processing and working memory share neural system resources.
authors.affiliation: Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry, University of California, Los Angeles 760 Westwood Plaza, Los Angeles, CA 90095, USA. fsabb@mednet.ucla.edu
authors.forename: Fred W
authors.initials: FW
authors.lastname: Sabb
authors.forename: Robert M
authors.initials: RM
authors.lastname: Bilder
authors.forename: Maggie
authors.initials: M
authors.lastname: Chou
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Bookheimer
mesh_terms: D000293:Adolescent; D000328:Adult; D001245:Association Learning / Q000502:physiology; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D004292:Dominance, Cerebral / Q000502:physiology; D005625:Frontal Lobe / Q000502:physiology*; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D011340:Problem Solving / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D012691:Serial Learning / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D014706:Verbal Learning / Q000502:physiology*