title: Normalisation of brain connectivity through compensatory behaviour, despite congenital hand absence.
abstract: Previously we showed, using task-evoked fMRI, that compensatory intact hand usage after amputation facilitates remapping of limb representations in the cortical territory of the missing hand (Makin et al., 2013a). Here we show that compensatory arm usage in individuals born without a hand (one-handers) reflects functional connectivity of spontaneous brain activity in the cortical hand region. Compared with two-handed controls, one-handers showed reduced symmetry of hand region inter-hemispheric resting-state functional connectivity and corticospinal white matter microstructure. Nevertheless, those one-handers who more frequently use their residual (handless) arm for typically bimanual daily tasks also showed more symmetrical functional connectivity of the hand region, demonstrating that adaptive behaviour drives long-range brain organisation. We therefore suggest that compensatory arm usage maintains symmetrical sensorimotor functional connectivity in one-handers. Since variability in spontaneous functional connectivity in our study reflects ecological behaviour, we propose that inter-hemispheric symmetry, typically observed in resting sensorimotor networks, depends on coordinated motor behaviour in daily life.
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Avital
authors.initials: A
authors.lastname: Hahamy
authors.affiliation: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Stamatios N
authors.initials: SN
authors.lastname: Sotiropoulos
authors.affiliation: Oxford Centre for Enablement, Nuffield Orthopaedic Centre, Oxford, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Henderson Slater
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Rafael
authors.initials: R
authors.lastname: Malach
authors.affiliation: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Heidi
authors.initials: H
authors.lastname: Johansen-Berg
authors.affiliation: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Tamar R
authors.initials: TR
authors.lastname: Makin
mesh_terms: D000328:Adult; D001519:Behavior; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D003710:Demography; D006228:Hand Deformities, Congenital / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology*; D011712:Pyramidal Tracts / Q000473:pathology / Q000503:physiopathology; D012146:Rest; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: human; neuroimaging; neuroscience; plasticity; rehabilitation