title: The role of the dorsal stream for gesture production.
abstract: Skilled gestures require the integrity of the neural networks involved in storage, retrieval, and execution of motor programs. Premotor cortex and/or parietal cortex lesions frequently produce deficits during performance of gestures, transitive more than intransitive. The dorsal stream links object information with object action, suggesting that mechanical knowledge of tool use is stored focally in the brain. Using event-related fMRI, we explored activity during instructed-delay transitive and intransitive hand gestures. The comparison between planning-preparation and execution of gestures demonstrated a temporal rostral to caudal gradient of activation in the ventral premotor cortex (PMv) and inferior to superior gradient of activation in the posterior parietal cortex (PPc). Comparison between transitive and intransitive gestures established a functional specificity within the dorsal stream for mechanical knowledge. Results demonstrate that not only PPc but also the PMv acts in the processing of sensorimotor information during gestures. This might be the substrate underlying selective deficits in ideomotor apraxia patients.
authors.affiliation: Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bldg. 10, Rm. 5N226, 10 Center Drive, MSC-1438, Bethesda, MD 20892-1428, USA.
authors.forename: Esteban A
authors.initials: EA
authors.lastname: Fridman
authors.forename: Ilka
authors.initials: I
authors.lastname: Immisch
authors.forename: Takashi
authors.initials: T
authors.lastname: Hanakawa
authors.forename: Stephan
authors.initials: S
authors.lastname: Bohlhalter
authors.forename: Daniel
authors.initials: D
authors.lastname: Waldvogel
authors.forename: Kenji
authors.initials: K
authors.lastname: Kansaku
authors.forename: Lewis
authors.initials: L
authors.lastname: Wheaton
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
mesh_terms: D000328:Adult; D001072:Apraxias / Q000503:physiopathology; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D005868:Gestures; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology