2.3. Definition of seed regions

We used as seeds three left-lateralized clusters that were identified by a previous coordinate-based activation likelihood estimation (ALE) (Eickhoff et al., 2012) meta-analysis on functional brain correlates of FTD (Wensing, 2017). These clusters were located in the superior temporal gyrus (STG) (110 voxels, volume: 880 mm³), the dorsal posterior middle temporal gyrus (dpMTG) (109 voxels; volume: 872 mm³), and the ventral posterior (vp)MTG (71 voxels; volume: 568 mm³) (Fig. 1A).

Seed regions used for functional connectivity map construction and illustration of the overall feature selection and multivariable predictive modeling procedure. A) We used three clusters as seeds that showed consistently aberrant activation associated with FTD in our previous activation likelihood estimation based meta-analysis (Wensing, 2017). MNI coordinates: left superior temporal gyrus (STG; −54, −28, 4); ventral posterior middle temporal gyrus (vpMTG; −46, −50, 22); and dorsal posterior MTG (dpMTG; −56, −56, 12). B) Flowchart illustrates the identification of rsFC patterns that were robustly associated with FTD specific dimensions, and the use of the identified rsFC as features for predictive modeling. GLM, general linear model; RVM, relevance vector machine; rsFC, resting-state functional connectivity; FTD, formal thought disorder.