Stability of functional network connectivity (FNC) values across multiple spatial normalization pipelines in spatially constrained independent component analysis

The reliability of functional network connectivity (FNC) measured using independent component analysis (ICA) has frequently been explored within the literature, with results displaying varying levels of reliability and demonstrating that minor changes in data preprocessing procedures can significantly alter FC results and reliability. However, one important avenue of research that has not been explored within the current literature is the effect of spatial normalization techniques on FNC reliability. Spatially constrained independent component analysis techniques such as multi-objective optimization with reference (MOO-ICAR) is one of many methods used to study brain functional connectivity (FC) using fMRI that is theoretically robust to variations which may arise in data as a result of normalization procedures. In this work, we deploy MOO-ICAR across 30 different spatial normalization pipelines varying across participant template, normalization modality (anatomical vs functional), and one vs. two-stage warps to MNI space. Most components display relatively high consistency intraclass-correlation coefficients (ICCs), with the vast majoritv (~80%) ereater than 0.5.