Figure 1
From: Perception of urge-to-cough and dyspnea in healthy smokers with decreased cough reflex sensitivity
Comparisons of cough reflex sensitivity between non-smokers and smokers. (A) Cough reflex sensitivities are expressed as the log transformation of the lowest concentration of citric acid that elicited two or more coughs (C2). (B) Cough reflex sensitivities are expressed as the log transformation of the lowest concentration of citric acid that elicited five or more coughs (C5). Open circles and error bars indicate the mean value and the standard deviation in each group, respectively.