title: Prefrontal cortex asymmetry for memory encoding of words and abstract shapes.
abstract: Previous work suggested a differential contribution of prefrontal cortex (PFC) to successful encoding depending on the stimulus material. Here, we tested the hypothesis that encoding of words preferentially involves the left PFC, while encoding of nonverbal items (abstract shapes) relies on the right PFC. We used an experimental design that evaluated encoding of both words and abstract shapes in the same healthy volunteers. A transient virtual lesion of the left or the right PFC was elicited with transcranial magnetic stimulation (TMS) while subjects memorized verbal and nonverbal items. We found that encoding of verbal material was disrupted by left PFC stimulation, whereas encoding of nonverbal material was disrupted by right PFC stimulation. These results demonstrate a functionally relevant lateralization of prefrontal contribution for verbal and nonverbal memory encoding.
authors.affiliation: Human Cortical Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD 20892-1430, USA.
authors.forename: Agnes
authors.initials: A
authors.lastname: Floel
authors.forename: David
authors.initials: D
authors.lastname: Poeppel
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Buffalo
authors.forename: Allen
authors.initials: A
authors.lastname: Braun
authors.forename: Carolyn W-H
authors.initials: CW
authors.lastname: Wu
authors.forename: Hyae-Jung
authors.initials: HJ
authors.lastname: Seo
authors.forename: Katja
authors.initials: K
authors.lastname: Stefan
authors.forename: Stefan
authors.initials: S
authors.lastname: Knecht
authors.forename: Leonardo G
authors.initials: LG
authors.lastname: Cohen
mesh_terms: D000328:Adult; D004574:Electromagnetic Fields; D005260:Female; D005556:Form Perception / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009068:Movement / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D011932:Reading; D013238:Stereotaxic Techniques