marginally significantp = .055
Furthermore, the MANCOVA on the same aPET ROI and the bilateral OFC fNIRS revealed a significant group effect [ F (6, 174) = 6.64, p < .001], leading to a significant effect on amyloid PET [ F (3, 88) = 11.46, p < .001] and a marginally significant effect on fNIRS [ F (3, 88) = 2.63, p = .055], Overall, Fig 6 shows that the amyloid PET signal tends to better differentiate the AD group from others, and the fNIRS signal tends to differentiate the SMI group from the other groups. fNIRS and anatomical measures When the LME model was fitted to the anatomical measures, no significant correlation between the fNIRS ROIs and gray volume or cortical thickness was found above and beyond what the group difference could explain.