The salience network drives switching between the default mode network (DMN), active when the brain is not focused on a task, and the central executive network (CEN), active during attention-demanding tasks. Combining dynamic causal modelling with independent component analysis, this work tested network switching in resting-state data from two independent datasets. The results confirm that the salience network is responsible for this switching and demonstrate the repeatability of the novel technique.
Resting state functional connectivity in the default mode network (DMN) of the human brain is linked to underlying white matter microstructure. Combining diffusion tensor imaging and resting state fMRI in 20 healthy elderly adults aged 56 to 83, the authors found that functional connectivity between the posterior cingulate and hippocampus was associated with white matter integrity in the cingulate bundle and related fiber tracts. A data-driven analysis confirmed a pattern of white matter tracts resembling the hypothesis-driven findings and linked to DMN connectivity. The results support the idea that DMN functional connectivity is grounded in distinct anatomical connections within cerebral white matter.
Cannabis use at age 16 is associated with psychotic-like experiences (PLEs) even after accounting for genetic risk for schizophrenia, according to an analysis of 1740 European adolescents from the IMAGEN cohort and replicated in 1223 individuals from a Dutch cohort. Polygenic risk scores for schizophrenia predicted both cannabis use and PLEs, and cannabis use remained a significant predictor of PLEs in models including genetic risk. However, no evidence was found that genetic risk mediates or moderates the cannabis–psychosis link. The findings suggest cannabis use is a risk factor for PLEs independent of genetic vulnerability to schizophrenia.