Animals have sophisticated mechanisms for coping with danger. Freezing is a unique state
that, upon threat detection, allows evidence to be gathered, response possibilities to be …

Upon increasing levels of threat, animals activate qualitatively different defensive modes,
including freezing and active fight-or-flight reactions. Whereas freezing is a form of …

Acutely challenging or threatening situations frequently require approach-avoidance
decisions. Acute threat triggers fast autonomic changes that prepare the body to freeze, fight …

When detecting a threat, humans and other animals engage in defensive behaviors and
supporting physiological adjustments that vary with threat imminence and potential …

Freezing is widely used as the main outcome measure for fear in animal studies. Freezing is
also getting attention more frequently in human stress research, as it is considered to play …

Survival in threatening situations depends on the selection and rapid execution of an
appropriate active or passive defensive response, yet the underlying brain circuitry is not …

Freezing, fleeing or fighting back are general defensive responses in many taxa. These
defenses are mutually exclusive, since a prey cannot simultaneously flee and fight, or freeze …

Environment and experience influence defensive behaviors, but the neural circuits
mediating such effects are not well understood. We describe a new experimental model in …

We propose a Survival Optimization System (SOS) to account for the strategies that humans
and other animals use to defend against recurring and novel threats. The SOS attempts to …

The appropriate selection of passive and active defensive behaviors in threatening
situations is essential for survival. Previous studies have shown that passive defensive …