Accuracy of respiratory symptom perception in persons with high and low negative affectivity

Abstract

Accuracy of respiratory symptom perception was investigated in different contexts in participants (N = 56) scoring high or low for negative affectivity (NA). Within subject-correlations were calculated between minute ventilation (frequency per minute × tidal volume) and the subjective symptom ‘faster and/or deeper breathing’ across 10 subsequent breathing trials of 2 min with varying air mixtures, containing fresh or foul smelling odours and/or 5.5% CO₂. Half the participants were given a positive information frame for the sensations (‘some air mixtures may induce a pleasantly arousing feeling, like when being in love’), whereas the other half was given a negative frame (‘some air mixtures may induce feelings of being anxious and distressed’). Interoceptive accuracy was overall fairly high (r = 0.56–0.74), but it dropped considerably (r = 0.27), when bodily sensations were induced in high NA persons in a negative information frame (interaction, p < 0.005). Interoceptive accuracy appears low when persons with high NA are in situations characterised by negative affective cues.

Keywords:

• Symptom perception
• Negative affectivity
• Interoception
• Accuracy
• Respiration

Acknowledgements

The study was supported by the Research Council of the University of Leuven (OT-97/16) and the Fund for Scientific Research, Flanders (FWO G.0399.98)

Notes

¹This is a typical differential learning paradigm in which the odour mixed with CO₂-enriched air is called a CS + and the one mixed with room air a CS−, while specific odour-CO₂ combinations are counterbalanced across subjects. Previous studies have shown more self-reported symptoms during CS + compared to CS− test trials, in which odours are presented alone (seeVanden Bergh et al., 2001, for a review of findings). In the present study, symptom learning did not occur (Winters, 2002).

² r = (e ^{2 z} − 1)/(e ^{2 z} + 1) in which e = 2.718…(see also the statistical function FISHER.INV(z) in the Excel2000 spreadsheet of Microsoft Office).

³Although all participants had the same odours and CO₂ trials an equal number of times, an additional feature of this differential learning paradigm was that foul smelling ammonia was mixed with 5.5% CO₂ during 3 trials for half of the participants, whereas for the other half the fresh smelling niaouli was mixed with 5.5% CO₂ during 3 trials. Typically, the experience of a foul smelling air mixture causing symptoms is experienced more negatively than a fresh smelling air mixture causing symptoms. Adding this factor to the design revealed a marginally significant ( p < 0.06) 3-way interaction, showing a close to zero interoceptive accuracy when high NA persons had been given negative information and had had 3 trials of a foul smelling odour mixed with 5.5% CO₂. Overall, this marginally significant finding is consistent with a gradient of accuracy in high NA persons becoming lower with more negative affective cues in the context.