Conditioning and memory paradigm schematic. Participants underwent threat acquisition and extinction on day 1, with items from one category (in this example, CS+ = tools) paired with shock during acquisition, and the other remaining nonreinforced (here, CS− = animals). SCRs were acquired through electrodes attached to participants’ left palms, with signal continuously sampled at 200 Hz, preprocessed via Autonomate (Green et al. 2014), and square-root-transformed. Threat expectancy ratings were made on a 3AFC scale (yes, unsure, and no). On day 2, participants underwent a specialized mnemonic similarity test (MST) involving the exact same images seen on day 1 (old targets), similar but nonidentical images from day 1 (similar lures), and novel category images (new foils). 3AFC MST ratings were made for each item (old, similar, and new).
