Manus Joseph Donahue1,2, Hans Hoogduin3,
Stephen M. Smith1,4, Jeroen CW Siero3, Natalia Petridou3,
Peter Jezzard1,2, Peter Luijten3, Jeroen Hendrikse3
1Clinical Neurology, Oxford University,
Oxford, United Kingdom; 2Physics Division, FMRIB Centre, Oxford,
United Kingdom; 3Radiology, University Medical Center Utrecht,
Utrecht, Netherlands; 4Analysis Division, FMRIB Centre, Oxford,
United Kingdom
Although
the use of spontaneous BOLD activity is being increasingly exploited for
connectivity studies, there is limited information available on how
spontaneous BOLD signal is influenced by different behavioural states. Here,
we investigate the effect of different behavioural states (eyes closed, eyes
open, constant-fist-clench, and finger tapping) on spontaneous BOLD signal in
the motor cortex at high field strength (7.0T) and high spatial resolution
(1.6x1.6x1.6 mm3). Results show that spontaneous signal coherence and, to a
lesser degree, amplitude are both dependent (P<0.05) on behavioural state;
implications of this phenomenon on evoked, spontaneous and 7.0T BOLD
experiments are discussed.