Fractional amplitude of low-frequency fluctuation and degree centrality in autistic children: a resting-state fMRI study

Autism negatively affects healthy cognitive development in children. As reliable neuroimaging markers, fractional amplitude of low-frequency fluctuation (fALFF) can reflect the intensity of spontaneous brain activity, and degree centrality (DC) can reflect connectivity of whole brain at voxel-level. By combining these two markers we can study the pathological mechanism of autism from more aspects. We investigated fALFF and weighted DC differences using functional magnetic resonance imaging (fMRI) data in 24 autistic children and 24 neurotypical children. Compared with neurotypical children, autistic children showed increased fALFF in right medial frontal gyrus, right dorsal anterior cingulate cortex, and bilateral ventral posterior cingulate cortex as well as decreased fALFF in bilateral visual cortex. Compared with neurotypical children, autistic children also showed increased weighted DC in left middle temporal gyrus, left middle frontal gyrus, and bilateral ventral posterior cingulate cortex as well as decreased weighted DC in left posterior cerbellar lobe and left visual cortex. Results in our study suggest that the pathological mechanism of autism is associated with spontaneous activity and connectivity changes in many brain regions, these changes will affect the ability of theory of mind.