The relevance and significance of the concept of a 'competition of cue
s' for the understanding of symptom perception in childhood asthma was
investigated during detection of externally applied resistive loads o
n breathing. The concept predicts that subjects would respond less fre
quently and less accurately during external stimulation. The sample co
nsisted of 36 children with and 36 without asthma, aged 7-18 years. De
tection of airflow was measured in a neutral and in an external stimul
ation condition. The children breathed through a facemask and responde
d to changes in airflow by pressing a button. The stimulus presented a
nd withdrawn was analogous to a decrease in lung function (Forced Expi
ratory Volume in one second) of approximate to 39%. Accuracy of detect
ion of airflow was defined as correct minus false positive responses t
o load stimuli. The results showed that children with and without asth
ma responded significantly less frequently during external stimulation
than in the neutral condition. However, the accuracy of detection amo
ng non-asthmatics was not affected by external stimulation. Children w
ith asthma responded significantly more accurately during external sti
mulation. The results are discussed in the light of children's accurac
y to perceive actual airways obstruction.