Learning to fear suffocation: a new paradigm for interoceptive fear conditioning.

The present study aimed to establish a new interoceptive fear conditioning paradigm. The conditioned stimulus (CS) was a flow resistor that slightly obstructs breathing; the unconditional stimulus (US) was a breathing occlusion. The paired group (N = 21) received 6 acquisition trials with paired CS-US presentations. The unpaired group (N = 19) received 6 trials of unpaired CS-US presentations. In the extinction phase, both groups were administered 6 CS-only trials. Measurements included startle eyeblink response, electrodermal responses, and self-reported US expectancy. In the paired group, startle blink responses were larger during CS compared to intertrial interval during acquisition and extinction. Electrodermal and US expectancies were larger for the paired than for the unpaired group during acquisition, but not during extinction. The present paradigm successfully established interoceptive fear conditioning with panic-relevant stimuli.