title: Distinction between Neural and Vascular BOLD Oscillations and Intertwined Heart Rate Oscillations at 0.1 Hz in the Resting State and during Movement.
abstract: In the resting state, blood oxygen level-dependent (BOLD) oscillations with a frequency of about 0.1 Hz are conspicuous. Whether their origin is neural or vascular is not yet fully understood. Furthermore, it is not clear whether these BOLD oscillations interact with slow oscillations in heart rate (HR). To address these two questions, we estimated phase-locking (PL) values between precentral gyrus (PCG) and insula in 25 scanner-naïve individuals during rest and stimulus-paced finger movements in both hemispheres. PL was quantified in terms of time delay and duration in the frequency band 0.07 to 0.13 Hz. Results revealed both positive and negative time delays. Positive time delays characterize neural BOLD oscillations leading in the PCG, whereas negative time delays represent vascular BOLD oscillations leading in the insula. About 50% of the participants revealed positive time delays distinctive for neural BOLD oscillations, either with short or long unilateral or bilateral phase-locking episodes. An expected preponderance of neural BOLD oscillations was found in the left hemisphere during right-handed movement and unexpectedly in the right hemisphere during rest. Only neural BOLD oscillations were significantly associated with heart rate variability (HRV) in the 0.1-Hz range in the first resting state. It is well known that participating in magnetic resonance imaging (MRI) studies may be frightening and cause anxiety. In this respect it is important to note that the most significant hemispheric asymmetry (p<0.002) with a right-sided dominance of neural BOLD and a left-sided dominance of vascular BOLD oscillations was found in the first resting session in the scanner-naïve individuals. Whether the enhanced left-sided perfusion (dominance of vascular BOLD) or the right-sided dominance of neural BOLD is related to the increased level of anxiety, attention or stress needs further research.
authors.affiliation: Institute of Neural Engineering, Graz University of Technology, Graz, Austria.|BioTechMed Graz, Graz, Austria.
authors.forename: Gert
authors.initials: G
authors.lastname: Pfurtscheller
authors.affiliation: BioTechMed Graz, Graz, Austria.|Institute of Psychology, University of Graz, Graz, Austria.|Health Psychology and Applied Diagnostics, University of Wuppertal, Wuppertal, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schwerdtfeger
authors.affiliation: BioTechMed Graz, Graz, Austria.|Institute of Psychology, University of Graz, Graz, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Brunner
authors.affiliation: BioTechMed Graz, Graz, Austria.|Institute of Medical Engineering, Graz University of Technology, Graz, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Aigner
authors.affiliation: Institute of Psychology, University of Graz, Graz, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Fink
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Brito
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal.
authors.forename: Marciano P
authors.initials: MP
authors.lastname: Carmo
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Andrade
mesh_terms: D000328:Adult; D001808:Blood Vessels / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D054022:Cerebrum / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D010100:Oxygen / Q000097:blood*; D012146:Rest / Q000502:physiology*; D018709:Statistics, Nonparametric; D013997:Time Factors; D055815:Young Adult
chemical_list: D010100:Oxygen