Pavlovian defense conditioning

The paradigm behind most of what is known about survival circuit anatomy, and the empirical base of LeDoux’s career. See ledoux-2012-survival-circuits.

The naming argument

Conventionally fear conditioning. LeDoux (2012) renames it Pavlovian defense conditioning on purpose: the procedure conditions defensive responding, and whether the animal feels afraid is a separate question the paradigm cannot address. Keeping “fear” in the name is precisely the move — using introspective feeling words as guideposts to animal phenomena — the survival circuit framework exists to block. The rename is not cosmetic; it is the thesis applied to the method. See basic-emotions, can-we-know-animal-feelings.

Circuit

Sensory inputs reach the lateral amygdala (LA); LA connects to the central amygdala (CEA) directly and indirectly via basal (BA), accessory basal (ABA), and intercalated (ITC) nuclei; medial CEA projects to ventrolateral PAG, whose outputs to motor control regions produce freezing. Unconditioned threats route differently — olfactory ones via vomeronasal → MEA → VMH → PMH → dorsal PAG. Full detail on amygdala.

What it measures beyond freezing

The same CS does three jobs (LeDoux’s Table 1), which is why the paradigm underwrites the emotion/motivation/reinforcement unification rather than just threat learning:

• Trigger: elicits innate defensive responses.
• Incentive: suppresses food-motivated bar-pressing (Estes & Skinner 1941), facilitates aversively motivated behaviour (Hammond 1970).
• Reinforcer: rats learn new instrumental responses rewarded by elimination of an aversive CS (Cain & LeDoux 2007).

Relation to this wiki’s clinical material

The direct descendant in the interoception literature is interoceptive-exposure — extinction logic applied to feared bodily sensations rather than external cues. The bridge is LeDoux’s own note that the PAG detects internal physiological signals triggering defense (Schimitel et al. 2012, suffocation alarm): if interoceptive states can serve as unconditioned triggers, then panic-relevant conditioning is a survival circuit phenomenon in his sense. Expect this to become load-bearing when the Week 8 panic/interoception sources (Ehlers; van der Does & Ehlers; Zoellner & Craske) are ingested.