title: fMRI characterisation of widespread brain networks relevant for behavioural variability in fine hand motor control with and without visual feedback.
abstract: A bilateral visuo-parietal-motor network is responsible for fine control of hand movements. However, the sub-regions which are devoted to maintenance of contraction stability and how these processes fluctuate with trial-quality of task execution and in the presence/absence of visual feedback remains unclear. We addressed this by integrating behavioural and fMRI measurements during right-hand isometric compression of a compliant rubber bulb, at 10% and 30% of maximum voluntary contraction, both with and without visual feedback of the applied force. We quantified single-trial behavioural performance during 1) the whole task period and 2) stable contraction maintenance, and regressed these metrics against the fMRI data to identify the brain activity most relevant to trial-by-trial fluctuations in performance during specific task phases. fMRI-behaviour correlations in a bilateral network of visual, premotor, primary motor, parietal and inferior frontal cortical regions emerged during performance of the entire feedback task, but only in premotor, parietal cortex and thalamus during the stable contraction period. The trials with the best task performance showed increased bilaterality and amplitude of fMRI responses. With feedback, stronger BOLD-behaviour coupling was found during 10% compared to 30% contractions. Only a small subset of regions in this network were weakly correlated with behaviour without feedback, despite wider network activated during this task than in the presence of feedback. These findings reflect a more focused network strongly coupled to behavioural fluctuations when providing visual feedback, whereas without it the task recruited widespread brain activity almost uncoupled from behavioural performance.
authors.affiliation: Birmingham University Imaging Centre (BUIC), School of Psychology, University of Birmingham, Edgbaston, Birmingham, UK. Electronic address: s.d.mayhew@bham.ac.uk.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Mayhew
authors.affiliation: Birmingham University Imaging Centre (BUIC), School of Psychology, University of Birmingham, Edgbaston, Birmingham, UK; Laboratory of Electrophysiology for Translational Neuroscience (LET'S) - ISTC - CNR, Fatebenefratelli Hospital Isola Tiberina, Rome, Italy; Movement Control and Neuroplasticity Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium.
authors.forename: Camillo
authors.initials: C
authors.lastname: Porcaro
authors.affiliation: Laboratory of Electrophysiology for Translational Neuroscience (LET'S) - ISTC - CNR, Fatebenefratelli Hospital Isola Tiberina, Rome, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Tecchio
authors.affiliation: Birmingham University Imaging Centre (BUIC), School of Psychology, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Bagshaw
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging* / Q000502:physiology*; D001931:Brain Mapping; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006225:Hand / Q000294:innervation / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007537:Isometric Contraction; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009415:Nerve Net / Q000000981:diagnostic imaging* / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D013788:Thalamus / Q000502:physiology; D055815:Young Adult
keywords: Brain network; Fatigue; Isometric contraction; Performance; Single-trial