Abstract

Background. Dyspnea is the cardinal symptom in patients with COPD. Dyspnea is suggested to be a bodily error signal, representing a mismatch between increased ventilatory demand and insufficient ventilatory response. Error positivity (Pe) is an event-related potential in the electroencephalogram (EEG) following an error response in forced choice reaction tasks, and suggested to reflect error awareness. However, whether COPD patients show greater error awareness remains untested. We hypothesized that patients would show higher Pe amplitudes in a computerized behavioral task compared to healthy controls, which would further relate to increased experiences of dyspnea. Methods. Using high-density EEG, 10 COPD patients (Age yrs=69±7, FEV1%pred=58±11) and 10 healthy, age-matched controls (Age yrs=71±6, FEV1%pred=102±12) performed the arrowhead version of the Flanker task during two experimental blocks of unloaded breathing, each lasting approximately 1.5 minutes. Pe was defined as the mean amplitude of the positive EEG deflection between 150 and 400 ms after error commission at centroparietal scalp positions. Results. An independent sample t-test showed stronger Pe amplitudes in patients (M=3.1 µV, SD=2.61) compared to controls (M=.63 µV, SD=1.86); t(18)=-2.43, p=.026. While self-reports of dyspnea intensity, unpleasantness and fear were significantly higher in patients compared to controls, Pe amplitudes were not correlated with self-reports (r?s<-.45; p?s>.2). Conclusions. COPD patients showed a greater awareness of errors compared to healthy controls which, however, was not related to dyspnea experiences and fear. Given the small sample size, these findings need confirmation in a larger sample in order to draw general conclusions.