Learning to fear suffocation: A new paradigm for interoceptive fear conditioning

Abstract

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 panicrelevant stimuli.

Learned Fear of Gastrointestinal Sensations in Healthy Adults

“…Yet, the experimental group still responded with a fear-potentiated startle to the CS, relative to the control group. This is very much in line with earlier findings using respiratory sensations as CS and US in an interoceptive associative learning paradigm 14 . Whereas fear-conditioned changes in skin conductance responses and in US expectancy primarily reflect explicit knowledge of the CS-US contingency, startle potentiation is thought to more directly reflect subcortical, amygdaladependent emotional learning that can dissociate from the former measures 19,20 .…”

“…Throughout the study, participants posed their dominant hand on a custom-built dial 14,15 , continuously rating the extent to which they expected the US in the following seconds. The scale of the dial ranged from 0 to 100.…”

Neuroimaging of central breathlessness mechanisms

“…conditioned fear [36]). Such studies might better be performed in a clinical population, although fear conditioning paradigms in healthy volunteers may yield useful insights [37].…”

Reprint of “Learning to breathe? Feedforward regulation of the inspiratory motor drive”

“…Up till now, findings from our lab generally suggest that a fear response is necessary to establish feedforward learning in adult human breathing behavior. Anticipatory fear responses were observed when using breathing loads and occlusions as US (Pappens et al, 2011(Pappens et al, , 2012a(Pappens et al, , 2013. In addition, to these anticipatory fear responses a small change in breathing behavior was observed.…”

“…Mechanical perturbations such as breathing loads and occlusions were successfully introduced as CS or US in fear learning paradigms (Pappens et al, 2011(Pappens et al, , 2012a. In two experiments, Pappens et al (2013) compared an interoceptive CS (non-aversive resistive load) with an exteroceptive CS (neutral picture) in a fear learning paradigm with an aversive, strong resistive load as the US.…”