Significantly altered regions of ALFF values for slow-4 in participants with schizophrenia, bipolar disorder and major depressive disorder, and healthy controls (A) by ANCOVA, (B) between schizophrenia and controls, (C) between bipolar disorder and controls, and (D) between major depressive disorder and controls. Significant at p < 0.05, Alphasim correction. ALFF = amplitude of low-frequency fluctuation; ANCOVA = analysis of covariance.