Defensive freezing and its relation to approach-avoidance decision-making under threat

Successful responding to acutely threatening situations requires adequate approach-avoidance decisions. However, it is unclear how threat-induced states –like freezing-related bradycardia– impact weighing of the potential outcomes of such value-based decisions. Insight into the underlying computations is essential to improve interventions for maladaptive decisions, for instance in anxiety patients and first-responders. Forty-two participants made passive and active approach-avoidance decisions under threat-of-shock when confronted with mixed outcome-prospects (varying money and shock amounts). Choice behavior was best predicted by a model including individual action-tendencies and bradycardia, beyond subjective value of outcome. Moreover, threat-related bradycardia interacted with subjective value, depending on the action-context (passive-vs-active). Specifically, in action-contexts incongruent with participants’ intrinsic action-tendencies, strong freezers showed diminished effects of subjective value on choice. These mechanistic insights into approach-avoidance conflict-resolution may inspire freezing-reducing techniques to optimize decision-making under threat. Critically, they demonstrate the relevance of incorporating internal psychophysiological states and external action-contexts into models of decision-making.