Project 7. Investigated point-process ALFF as a measure of another aspect of resting state brain activity

Design background

Resting-state fluctuation amplitude (RSFA) characterizes the local features of spontaneous brain activity from the perspective of functional segregation. Several studies have suggested that resting-state functional connectivity (RSFC) is probably driven by a few discrete and brief instances of spontaneous neuronal events rather than continuous activity. In this study, we wondered whether the relavant information of RSFA could also be sufficiently represented by these temporally sparse events.

Methods

We tested the equivalence between RSFA measurement (fractional amplitude of low frequency fluctuation (fALFF) in particular) and its point-process representation (PP-RSFA, i.e. the number of time points above a predefined threshold) by examining the their correlations across subjects as well as the sensitivities in detecting between-condition differences.

fig7-1

Results

The results demonstrated that PP-RSFA was significantly correlated with fALFF in almost all the gray matter voxels, and had comparable sensitivity with fALFF in detecting the differences between eyes open and eyes closed states, only if the constraint of local synchronization was imposed. Further analysis indicated that the efficiency of such constraint was primarily attributed to the temporal regularity of the discrete spontaneous events.

fig7-2

Co-author: Dongqiang Liu, Associate Prof.
Copyright: Ruidi Wang.
Contact: [email protected] & [email protected]