title: Hemispheric differences of motor execution: a near-infrared spectroscopy study.
abstract: Distal movements of the limbs are predominantly controlled by the contralateral hemisphere. However, functional neuroimaging studies do not unequivocally demonstrate a lateralization of the cerebral activation during hand movements. While some studies show a predominant activation of the contralateral hemisphere, other studies provide evidence for a symmetrically distributed bihemispheric activation. However, the divergent results may also be due to methodological shortcomings. Therefore, the present study using functional near-infrared spectroscopy examines cerebral activation in both hemispheres during motor actions of the right and left hands. Twenty participants performed a flexion/extension task with the right- or left-hand thumb. Cerebral oxygenation changes were recorded from 48 channels over the primary motor, pre-motor, supplementary motor, primary somatosensory cortex, subcentral area, and the supramarginal gyrus of each hemisphere. A consistent increase of cerebral oxygenation was found for oxygenated and for total hemoglobin in the hemisphere contralateral to the moving hand, regardless of the laterality. These findings are in line with previous data from localization [1-3] and brain imaging studies [4-6]. The present data support the proposition that there is no hemispheric specialization for simple distal motor tasks. Both hemispheres are equally activated during movement of the contralateral upper limb.
authors.affiliation: Department of Neurology, Psychosomatic Medicine and Psychiatry, Institute of Health Promotion and Clinical Movement Science, German Sport University, Cologne, Germany. in.helmich@gmail.com.
authors.forename: Ingo
authors.initials: I
authors.lastname: Helmich
authors.affiliation: Department of Neurology, Psychosomatic Medicine and Psychiatry, Institute of Health Promotion and Clinical Movement Science, German Sport University, Cologne, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Rein
authors.affiliation: Department of Neurology, Psychosomatic Medicine and Psychiatry, Institute of Health Promotion and Clinical Movement Science, German Sport University, Cologne, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Niermann
authors.affiliation: Department of Neurology, Psychosomatic Medicine and Psychiatry, Institute of Health Promotion and Clinical Movement Science, German Sport University, Cologne, Germany.
authors.forename: Hedda
authors.initials: H
authors.lastname: Lausberg
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D059907:Functional Neuroimaging / Q000379:methods; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000378:metabolism / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism; D011597:Psychomotor Performance / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D013933:Thumb / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen