Psychophysiological interaction (PPI) analysis. The PPI analysis contrasted the unconditioned stimulus (US) versus omitted US, modeling the change in regional coupling between the seed induced by the delivery of the US. The green sphere indicates the location of (A) the putamen seed and (B) the parahippocampal seed. Group differences (trauma-exposed non-PTSD control (TENC) > PTSD) in psychophysiological interaction effects are displayed at a threshold of T > 3 on a template magnetic resonance imaging (MRI) scan.
Linnman et al. Biology of Mood & Anxiety Disorders 2011 1:8 doi:10.1186/2045-5380-1-8