Generalization of Fear to Respiratory Sensations.

Interoceptive fear conditioning (IFC), fear generalization and a lack of safety learning have all been hypothesized to play a role in the pathogenesis of panic disorder, but have never been examined in a single paradigm. The present study aims to investigate whether healthy participants (N=43) can learn both fear and safety to an interoceptive sensation, and whether such learning generalizes to other, similar sensations. Two intensities of inspiratory breathing impairment (induced by two pressure threshold loads of 6 and 25 cm H2O) served as interoceptive conditional stimuli (CSs) in a differential conditioning paradigm.

Interoceptive fear learning to mild breathlessness as a laboratory model for unexpected panic attacks.

Fear learning is thought to play an important role in panic disorder. Benign interoceptive sensations can become predictors (conditioned stimuli - CSs) of massive fear when experienced in the context of an initial panic attack (unconditioned stimulus - US). The mere encounter of these CSs on a later moment can induce anxiety and fear, and precipitate a new panic attack.

Retention of perceptual generalization of fear extinction.

Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h.

Resting heart rate variability predicts safety learning and fear extinction in an interoceptive fear conditioning paradigm.

This study aimed to investigate whether interindividual differences in autonomic inhibitory control predict safety learning and fear extinction in an interoceptive fear conditioning paradigm. Data from a previously reported study (N = 40) were extended (N = 17) and re-analyzed to test whether healthy participants' resting heart rate variability (HRV) - a proxy of cardiac vagal tone - predicts learning performance. The conditioned stimulus (CS) was a slight sensation of breathlessness induced by a flow resistor, the unconditioned stimulus (US) was an aversive short-lasting suffocation experience induced by a complete occlusion of the breathing circuitry.

Fear of suffocation alters respiration during obstructed breathing.

We aimed to investigate whether fear of suffocation predicts healthy persons' respiratory and affective responses to obstructed breathing as evoked by inspiratory resistive loads. Participants (N = 27 women, ages between 18 and 21 years) completed the Fear of Suffocation scale and underwent 16 trials in which an inspiratory resistive load of 15 cmH(2)O/l/s (small) or 40 cmH(2)O/l/s (large) was added to the breathing circuit for 40 s. Fear of suffocation was associated with higher arousal ratings for both loads.

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.

Psychophysiological responses to CO₂inhalation.

Inhalation of CO(2)-enriched air has been used as a laboratory model for a number of anxiety disorders, such as general anxiety disorder and panic disorder. Because studies describing psychophysiological responses to this challenge are scarce, the present studies investigated skin conductance level, eyeblink startle, self-reported anxiety and fractional end-tidal carbon dioxide during inhalation of CO(2)-enriched air. In study 1, thirty-five healthy volunteers inhaled 7.

Learning to fear obstructed breathing: comparing interoceptive and exteroceptive cues.

The present study investigated interoceptive fear conditioning (IFC) to an interoceptive and exteroceptive conditional stimulus (CS) with a severe respiratory load applied for 30s as the unconditional stimulus (US). CSs were another, weak respiratory load in the intero-IFC study (N=74), and a neutral picture in the extero-IFC study (N=42). CSs preceded the US in the paired groups, whereas the unpaired groups received the same number of unpaired CSs and USs.

Psychophysiological responses to inspiratory resistive loads.

Fear of interoceptive sensations is relevant for a number of psychiatric and somatic disorders. Pappens et al. (2010, Biol.

Defense reactions to interoceptive threats: a comparison between loaded breathing and aversive picture viewing.

Human fear research has mostly applied exteroceptive stimuli to induce fear. Interoceptive sensations however can also be very threatening and play a major role in a number of anxiety disorders. In this study, we compared affective responses to inspiratory resistive loads with those to aversive pictures.