Gradients of fear: How perception influences fear generalization

Neural reactivity tracks fear generalization gradients.

Recent studies on fear generalization have demonstrated that fear-potentiated startle and skin conductance responses to a conditioned stimulus (CS) generalize to similar stimuli, with the strength of the fear response linked to perceptual similarity to the CS. The aim of the present study was to extend this work by examining neural correlates of fear generalization. An initial experiment (N=8) ...

Emotion Fear Generalization Gradients in Visuospatial Attention

Neurobehavioral mechanisms of human fear generalization

While much research has elucidated the neurobiology of fear learning, the neural systems supporting the generalization of learned fear are unknown. Using functional magnetic resonance imaging (fMRI), we show that regions involved in the acquisition of fear support the generalization of fear to stimuli that are similar to a learned threat, but vary in fear intensity value. Behaviorally, subjects...

Effects of discrimination training on fear generalization gradients and perceptual classification in humans.

To examine the effect of discriminative fear conditioning on the shape of the generalization gradient, two groups of participants first learned to discriminate between two color stimuli, one paired with an electrical shock (conditional stimulus, CS+) and the other explicitly unpaired (CS-). The CS+ was held constant as an intermediate (ambiguous) value along the blue-green color dimension while...

Asymmetrical stimulus generalization following differential fear conditioning.

Rodent ultrasonic vocalizations (USVs) are ethologically critical social signals. Rats emit 22kHz USVs and 50kHz USVs, respectively, in conjunction with negative and positive affective states. Little is known about what controls emotional reactivity to these social signals. Using male Sprague-Dawley rats, we examined unconditional and conditional freezing behavior in response to the following a...