Active/Passive Avoidance Shuttle Box

The shuttle box is a two-compartment chamber with independently controlled shock grids, lights, and speakers. In active avoidance, a conditioned stimulus (tone or light) precedes a foot shock, and the animal learns to cross into the other compartment during the CS to avoid the shock entirely. In passive (inhibitory) avoidance, the animal learns the opposite: to withhold a movement it would naturally make, and retention is read from how long it hesitates before entering the shock-paired side.

Two-way avoidance is deliberately harder to acquire than one-way avoidance, and the reason is diagnostic. The compartment the animal escapes into is the same one it was shocked in on an earlier trial, so the safe side is never unambiguously safe. That conflict pits the learned shuttle response against the rodent's species-specific defense reaction — freezing — which is why an animal can look like a poor learner when it is in fact freezing well. Reading avoidance responses without also reading freezing and inter-trial crossings will misattribute a defensive strategy to a memory deficit.

ConductVision scores crossings, latencies, and freezing frame by frame across both compartments, and separates avoidance from escape by aligning each crossing to CS and shock onset.