Realignments have come to seem inevitable, and a fragmentation of the CIS with them.This week Mr Yeltsin, having sacked his disgruntled defence minister, Igor Rodionov (see article), was due to set one such realignment in motion by co-signing on Friday a "union charter" with the president of Belarus, Alexander Lukashenka, a lone advocate of full integration with Russia.
Single subject preprocessing consisted of the following steps: realignment for motion correction, normalization to standard stereotaxic coordinates (MNI coordinates), smoothing at 6 mm3 voxels, and first-level single subject data analysis.
A 4th degree B-spline function without weighting and without warping was used for image realignment (head motion was less than 1-mm translations and 1°-rotations for all scans for all fMRI runs).
After the realignment procedure for motion correction among the frames, motion corrected PET frames were summed, co-registered to the corresponding individual MRI and transformed into standardized stereotaxic space.
The following procedures were applied: slice timing adjustment; realignment for head motion correction (subjects with head motion >2.0-mm translation or >2.0o rotation were excluded); spatial normalization to standard Montreal Neurological Institute (MNI) template with a resampling voxel size of 3 × 3 × 3 mm; spatial smoothing with a Gaussian kernel of 4 mm.
Data pre-processing for functional volumes included image realignment, three-dimensional motion correction, linear de-trending, temporal frequency filtering with high pass filter, and spatial smoothing with a 4-mm Gaussian kernel (full width at half-maximum).
Nevertheless we took the precaution of modelling realignment parameters reflecting motion as a potential confound.
Preprocessing consisted of correction for field inhomogeneities (Hutton et al., 2002), motion realignment, high-pass filtering (cut-off frequency of 1/128 s), and co-registration between functional and individual anatomical data.
Afterwards, the following procedures were carried out as follows: slice-timing adjustment, realignment for head motion correction, spatial normalization to the Montreal Neurological Institute (MNI) template (resampling voxel size = 3 × 3 × 3 mm) and smoothing with an isotropic Gaussian kernel (FWHM = 6 mm), and detrending and filtering (0.01 0.08 Hz).
Preprocessing of the image volumes included realignment of head motions, slice-time correction with reference to the middle slice acquired in time, normalization to the EPI-template based on the Montreal Neurological Institute MNII) reference brain (resampled voxel size 3 × 3 × 3 mm), and spatial smoothing with a Gaussian kernel (8 mm at full-width half-maximum).
