My former MEi:CogSci master student Lora Minkova and I wrote this paper where we used DCM to investigate amygdala effective connectivity. We conducted an affective counting Stroop task fMRI experiment in patients with social anxiety disorders and healthy controls. An increased amygdalar activation and reduced amygdala down-regulation were found during low cognitive load in patients.
Lora Minkova & Ronald Sladky, Georg S. Kranz, Michael Woletz, Nicole Geissberger, Christoph Kraus, Rupert Lanzenberger, Christian Windischberger, 2017. Task-dependent modulation of amygdala connectivity in social anxiety disorder. Psychiatry Research: Neuroimaging, Volume 262, 30 April 2017, Pages 39–46.