The development of an fMRI protocol to investigate vmPFC network topology underlying the generalization of behavioral control

Description: Experiencing behavioral control over stress can have long lasting and generalizing effects. The controllability of a physical threat, for example, affects the processing of subsequent social stress. Animal research has shown that the vmPFC plays a critical role in behavioral control and orchestrating subcortical responses. However, translational research on these neural systems in humans is sparse and we therefore aimed to develop a paradigm to test the generalization effect of behavioral control on vmPFC functioning. A pilot study was performed in which subjects (n=18) were first randomly assigned to one of two versions of a signal detection task, where feedback was either paired with a controllable or an uncontrollable mild shock. Subsequently, subjects underwent a social evaluative threat fMRI paradigm to measure their response to the anticipation of speaking in public. The analyses tested whether the controllability manipulation influenced behavioral and physiological responses and vmPFC network topology. Results showed that overall subjects were faster to respond to potential shock trials in the signal detection task, and there was a trend significant difference between the controllable or uncontrollable group. No significant differences between the two groups were observed on other behavioral or physiological responses. fMRI results showed higher vmPFC efficiency in the controllable threat group at baseline and recovery but similar to the uncontrollable group during speech anticipation. The current report establishes the feasibility of the protocol and adequately-powered follow-up research is needed to further evaluate the generalization effect on the behavioral, physiological and neural level.