Analysis methods
FMRI data processing was carried out using FEAT (FMRI Expert Analysis Tool) Version 5.98, part of FSL (FMRIB's Software Library, www.fmrib.ox.ac.uk/fsl). The following pre-statistics processing was applied; motion correction using MCFLIRT [Jenkinson 2002]; non-brain removal using BET [Smith 2002]; spatial smoothing using a Gaussian kernel of FWHM 8.0mm; grand-mean intensity normalisation of the entire 4D dataset by a single multiplicative factor; highpass temporal filtering (Gaussian-weighted least-squares straight line fitting, with sigma=50.0s); Gaussian lowpass temporal filtering HWHM 2.8s.
References
[Jenkinson 2002] M. Jenkinson and P. Bannister and M. Brady and S. Smith. Improved optimisation for the robust and accurate linear registration and motion correction of brain images. NeuroImage 17:2(825-841) 2002.
[Smith 2002] S. Smith. Fast Robust Automated Brain Extraction. Human Brain Mapping 17:3(143-155) 2002.
MCFLIRT Motion correction
Mean displacements: absolute=0.28mm, relative=0.08mm
