Page 164 - Like me, or else... - Michelle Achterberg

Chapter 6
angle = 80°; field of view (FOV, in mm) = 220.000 (rl) x 220.00 (ap) x 111.65 (fh); 37 slices). In addition, a high-resolution EPI scan was obtained for registration purposes (scan duration 46.2 sec; TR = 2.2 sec; TE = 30 ms, flip angle = 80°, FOV= 220.000 (rl) x 220.00 (ap) x 168.00 (fh), 84 slices), as well as a T1-weighted anatomical scan (scan duration 296.6 s; TR = 9.72 sec; TE = 4.59 ms, flip angle = 8°, FOV = 177.333 (rl) x 224.000 (ap) x 168.000 (fh), 140 slices). Since motion causes substantial artifacts within structural scans, we visually inspected the quality of the T1-weighted anatomical scan directly after acquisition. If the scan was affected by motion (blurry T1 image), we repeated the T1 scan. This was the case for 3% of the included participants.
Table 1. Comparison of demographic characteristics of replication samples I and II.
Sample I
78 45%
8%
2 (ADHD, GAD)
8.01 (0.69) 7.02 -9.07 103.75 (11.96) 80.00-137.50 7%
ADHD: Attention
Disorder; FD: Framewise Displacement
Data Preprocessing
The preprocessing of resting-state fMRI data was carried out using FMRIB’s Expert Analysis Tool (FEAT; version 6.00) as implemented in FSL version 5.09 (Smith et al., 2004). The following preprocessing steps were used: motion correction (MCFLIRT; Jenkinson et al. (2002)), slice time correction, removal of non-brain tissue using the Brain Extraction Tool (BET; Smith (2002)), spatial smoothing using a Gaussian kernel of 6 mm full width at half maximum, and high-pass temporal filtering (Gaussian weighted least-squares straight line fitting, with sigma = 100 sec, 0.01 Hz cut-off). To register fMRI scans to standard space, each subject’s functional scan was registered to the corresponding high resolution EPI
n Boys
Left handed AXIS-I disorder
Age (SD) Range
Mean IQ (SD) IQ range
Frames >0.5 mm FD
Sample II
78 44%
14%
1 (ADHD)
8.02 (0.69) 7.03 - 9.08 106.03 (12.26) 77.50-137.50 7%
Statistics
χ(1, N=156)=0.26, p=.872
χ(1, N=156)=1.65, p=.199
χ(1, N=156)=0.34, p=.560
t(154)= -.14, p=.887
t(154)=-1.17, p=.242 t(154)=.25, p=.800
deficit hyperactivity disorder; GAD: Generalized Anxiety
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