title: Spatiotemporal maps of brain activity underlying word generation and their modification during repetition priming.
abstract: Spatiotemporal maps of brain activity based on magnetoencephalography were used to observe sequential stages in language processing and their modification during repetition priming. Subjects performed word-stem completion and produced either novel or repeated (primed) words across trials. Activation passes from primary visual cortex (activated at approximately 100 msec after word presentation), to left anteroventral occipital ( approximately 180 msec), to cortex in and near Wernicke's ( approximately 210 msec) and then Broca's ( approximately 370 msec) areas. In addition, a posteroventral temporal area is activated simultaneously with posterosuperior temporal cortex. This area shows an early ( approximately 200-245 msec) increase in activation to repeated word stems. In contrast, prefrontal and anterior temporal regions showed activity reductions to repeated word stems late ( approximately 365-500 msec) in processing. These results tend to support classical models of language and suggest that an effect of direct item repetition is to allow word-form processing to increase its contribution to task performance while concurrently allowing reductions in time-consuming frontal temporal processing.
authors.affiliation: Department of Radiology, University of Utah, Salt Lake City, Utah 84105, USA.
authors.forename: R P
authors.initials: RP
authors.lastname: Dhond
authors.forename: R L
authors.initials: RL
authors.lastname: Buckner
authors.forename: A M
authors.initials: AM
authors.lastname: Dale
authors.forename: K
authors.initials: K
authors.lastname: Marinkovic
authors.forename: E
authors.initials: E
authors.lastname: Halgren
mesh_terms: D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D005625:Frontal Lobe / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D009778:Occipital Lobe / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D013060:Speech / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology; D014705:Verbal Behavior / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology; D014936:Word Association Tests