76 Chapter 3 SUPPLEMENT S3.4 fMRI data acquisition MR images were acquired at the LUMC using a Philips 3.0T Achieva MRI scanner equipped with a SENSE-32 channel head coil. For the eye contact task, T2*-weighted echo planar imaging (EPI) was used with the following parameters: TR = 2200 ms, TE = 30 ms, flip angle = 80°, FOV 114.7 × 220 × 220 mm, matrix size = 80 × 80, voxel size = 2.75 mm3, slice gap = 0.275 mm, 38 transverse slices in descending order. As the eye contact task was self-paced, number of volumes varied between participants (run 1: M = 152.6, SD = 12.2, range = 189 – 128; run 2: M = 149.1, SD = 12.3, range = 184 – 123). A structural 3D T1 scan was acquired with the following parameters: TR = 7.9 ms, TE = 3.5 ms, TI = 820 ms, flip angle: 8°, voxel size = 1 mm3, 155 transverse slices FOV 195.8 × 250 × 170.5 mm, matrix size = 228 × 177, duration: 4:11 min. The first five volumes were discarded to allow for equilibration of T1 saturation effects. A b0 field map was acquired with the following parameters: TR = 200 ms, TE = 3.2, matrix size = 80 × 80, with 38 slices, voxel size = 2.75 mm3. Task responses were self-paced and participants could press any button to display a box around the middle option and then press the button corresponding to their right index (to go left) and right middle finger (to go right) to move the box to their preferred answer. They could confirm their answer by pressing the button corresponding to their left index finger. The task was programmed and presented electronically and eye movement recordings were conducted using E-prime 2.0 (Tools Psychology Software, 2012) and participants could see the task through a mirror attached to the head coil. Foam inserts were used to restrict head motion if necessary. Scans were examined by a radiologist in case of any suspicion of abnormalities. Screen resolution was 1024 x 768 pixels. The videos were presented on the screen in 960 x 540 pixels. The task lasted approximately 11 minutes in total.
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