title: Initiation of voluntary movements at free will and ongoing 0.1-Hz BOLD oscillations in the insula-a pilot study.
abstract: Recently we hypothesized that the intention to initiate a voluntary movement at free will may be related to the dynamics of hemodynamic variables, which may be supported by the intertwining of networks for the timing of voluntary movements and the control of cardiovascular variables in the insula. In the present study voluntary movements of 3 healthy subjects were analyzed using fMRI scans at 1.83-s intervals along with the time course of slow hemodynamic changes in sensorimotor networks. For the analyses of BOLD time courses the Wavelet transform coherence (WTC) and calculation of phase-locking values were used. Analyzed was the frequency band between 0.07 and 0.13 Hz in the supplementary motor area (SMA) and insula, two widely separated regions co-active in motor behavior. BOLD signals displayed slow fluctuations, concentrated around 0.1 Hz whereby the intrinsic oscillations in the insula preceded those in the SMA by 0.5-1 s. These preliminary results suggest that slow hemodynamic changes in SMA and insula may condition the initiation of a voluntary movement at free will.
authors.affiliation: Institute for Knowledge Discovery (BCI Lab), Graz University of Technology Graz, Austria ; BioTechMed Graz, Austria.
authors.forename: Gert
authors.initials: G
authors.lastname: Pfurtscheller
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon Lisboa, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Andrade
authors.affiliation: BioTechMed Graz, Austria ; Institute of Psychology, University of Graz Graz, Austria.
authors.forename: Karl
authors.initials: K
authors.lastname: Koschutnig
authors.affiliation: Institute for Knowledge Discovery (BCI Lab), Graz University of Technology Graz, Austria ; BioTechMed Graz, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Brunner
authors.affiliation: Center for NeuroScience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Fernando Lopes
authors.initials: FL
authors.lastname: da Silva
keywords: 0.1-Hz oscillations; BOLD; fMRI; insula; voluntary movement