Neural reactivity tracks fear generalization gradients

► Fear generalization is the transfer of conditioned fear to perceptually similar stimuli. ► Physiological/behavioral responses follow a gradient linked to perceptual similarity of stimuli. ► In two fMRI experiments we replicate these gradients, localized to the insula, anterior cingulate, supplementary motor area and caudate. ► A paradigm is established to probe the neurocircuitry of generalization in anxiety.