Fig. 2.

Neural effects of anodal tDCS and DCM models.

(A) Statistical parametric maps showing greatest reduction in BOLD signal (uncorrected, P = 0.001) in left inferior frontal sulcus (1: IFS; z score 4.65; Ai) and ventral premotor (2: VPM; z score 3.50; Aii) as a consequence of anodal tDCS delivered during the naming task. (B) The open circles illustrate the 6 mm spherical volume of interest located at peaks of anodal tDCS effects. Regional time series data was drawn from these regions for each subject for the DCM analysis. (C) Zoom from panel B showing the fully connected Dynamic Causal Model (DCM) based on the effective connectivity of the same two regions of interest. Inputs were directed to either IFS or VPM.