Meulders A, et al. - Given that impaired selective fear learning is a core mechanism involved in excessive spreading of protective responses such as pain-related fear and avoidance leading to disability in chronic pain conditions, researchers investigated if patients with fibromyalgia (FM) show less selective threat learning than healthy controls (HCs) using the litmus test for selective learning effects, the blocking procedure. A novel selective learning task based around a clinical diary scenario was introduced and on a trial-by-trial basis, participants rated whether they expected certain situations (A, B, Z, and X) in the diary of a fictive FM patient would trigger pain in that patient. The HCs vs the patients with FM displayed blocking (ie, significant difference between B and X) within group comparisons. Differences in selective learning between patients with FM and HCs were directly assessed using a blocking procedure for the first time in this work.