Structural Brain Alterations in Mental Fatigue

Structural MRI data was acquired on a 3T General Electric scanner equipped with a 32-channel head coil. High resolution T1-weighted images were collected using a 3D fast spoiled gradient echo sequence covering 180 slices with 1 mm thickness. Acquisition details included: TR = 8.2 ms; TE = 3.2 ms; flip angle 12°; field of view 25 × 25 cm. Freesurfer version 5.3 was used for brain segmentation. For the subcortical measurements volume (mm³) was used, and for the cortical segmentation cortical thickness (mm) from the Destrieux atlas (Destrieux et al., 2010 (link)). Regions of interests (ROI) were defined as areas in which structural alterations have been observed in patients with ED, as compared to healthy controls, based on previous studies (Blix et al., 2013 (link), Savic, 2015 (link), Savic et al., 2018 (link)), while also being outlined in neuroanatomical models of mental fatigue (Chaudhuri and Behan, 2000 (link), Dobryakova et al., 2013 (link)). For the subcortical segmentations, we extracted the bilateral caudate and putamen volumes. For cortical thickness, we combined the bilateral superior and middle frontal gyri to produce a dorsolateral PFC ROI; the bilateral orbital gyri and sulci and gyrus rectus to produce a ventromedial PFC ROI; and the anterior and middle-anterior cingulate gyri and sulci to produce an ACC ROI.