Psychophysiological interaction (PPI) analysis
CORTEX
The final contrast examined changes in functional connectivity between Active Exteroception and Active Interoception. The anterior cingulate cortex (ACC) region of interest (Comparisons between active effects and active matchActExt = Active Exteroception; ActInt = Active Interoception; ActMatch = Active Matching.PPI effectsThe PPI was defined by the interaction of the [ActInt – ActExt] contrast * ACC activity.Psychophysiological interaction (PPI) analysis. Test-retest reliability of neuroimaging findings. To demonstrate the robustness and replicability of the results, conjunction analysis for the four main contrasts reported in this paper was conducted. As the TFCE algorithm does not currently perform conjunction analysis, and halving the sample size reduces experimental power, the baseline and postintervention sessions were each analyzed separately at 