The Effects of Repeated Dyspnea Exposure on Response Inhibition

Abstract

In order to treat dyspnea (=breathlessness) successfully, response inhibition (RI) as a major form of self-regulation is a premise. This is supported by research showing that self-regulation is associated with beneficial behavioral changes supporting treatment success in patients. Recent research showed that dyspnea has an impairing effect on RI, but the effects of repeated dyspnea exposure on RI remain unknown. Therefore, the present study tested the effects of repeated resistive load-induced dyspnea on RI over a 5-day period. Healthy volunteers (n = 34) performed the standard version of the Stroop task during baseline and dyspnea conditions on the first and fifth testing day and underwent an additional dyspnea exposure phase on each testing day. Variables of interest to investigate RI were reaction time, accuracy as well as the event-related potentials late positive complex (LPC) and N400 in the electroencephalogram. Reduced accuracy for incongruent compared to congruent stimuli during the dyspnea condition on the first testing day were found (p < 0.001). This was paralleled by a reduced LPC and an increased N400 for incongruent stimuli during the induction of dyspnea (p < 0.05). After undergoing dyspnea exposure, habituation of dyspnea intensity was evident. Importantly, on the fifth testing day, no differences between baseline, and dyspnea conditions were found for behavioral and electrophysiological measures of RI. These findings demonstrate that the impairing effect of dyspnea on RI disappeared after repeated dyspnea exposure in healthy participants. Translated to a clinical sample, it might cautiously be suggested that dyspnea exposure such as dyspnea perceived during physical exercise could reduce the impairing effect of dyspnea on RI which might have the potential to help increase self-regulation abilities and subsequent treatment efforts in dyspneic patients.

Keywords: LPC; N400; breathlessness; dyspnea; habituation; inhibition.

FIGURE 1

Sensor outline of the HydroCel Geodesic Sensor Net (with permission from Electrical Geodesics, Inc. Electrodes). The LPC and N400 were calculated with the sensors framed with yellow and purple color, respectively.

FIGURE 2

Dyspnea intensity and dyspnea unpleasantness ratings for all five testing days during the dyspnea exposure phases. Dots represent mean values. Error bars represent standard errors.

FIGURE 3

(A) Grand average waveforms (μV) for each condition at centro-parietal sites for congruent and incongruent stimuli for T1 (upper panel) and T5 (lower panel). The late positive complex (LPC) is highlighted from 400 to 600 ms. (B) Mean (SE) amplitudes (μV) for each condition for the LPC for congruent and incongruent stimuli for T1 (upper panel) and T5 (lower panel). ^∗p < 0.05.

FIGURE 4

Topographical illustration of the late positive complex and N400 for congruent and incongruent color-words during each condition for T1 and T5.

FIGURE 5

(A) Grand average waveforms (μV) during each condition at centro-parietal sites for congruent and incongruent stimuli for T1 (upper panel) and T5 (lower panel). The N400 is highlighted from 350 to 700 ms. (B) Mean (SE) amplitudes (μV) during each condition for the N400 for congruent and incongruent stimuli for T1 (upper panel) and T5 (lower panel). ^∗p < 0.05, ^∗∗p < 0.01.