Digging for Fool's Gold: Functional MRI of the Amygdala in (Post-)Active Military Personnel with Impulsive Aggression Problems

The original aim of the research presented in this thesis was to uncover new (f)MRI-based biomarkers of impulsive aggression problems in (post-)active military personnel. In that regard, the work presented here did not succeed. What it did succeed at, however, is demonstrating that amygdala-fMRI-based biomarkers of emotion processing in general, and by extension, impulsive aggression in particular, do not offer sustainable avenues for further/continued exploration. This includes targeted intervention strategies such as amygdala real-time fMRI neurofeedback. Future inquiries would do well to consider the multi-faceted nature of a phenotype as ostensibly uniform as impulsive aggression, and should appreciate more the network properties and (near-)criticality of the brain in all its glorious complexity. Bearing these limitations and recommendations in mind, however, neuroimaging research on impulsive aggression, or indeed, emotion processing as a whole, can still prove a source rich in new discoveries, provided one is willing to stop staring at the fool’s gold of the amygdala.