The investigation focused on differences in judgments of individuals experienced with breathlessness (due to chronic pulmonary disease, n = 30) and those without chronic experience (normal lung function, n = 30). The research had three major aims. The first tested whether symptomatic individuals made decisions based in logic and probability or some other means, such as natural assessment strategies. Participants were asked to judge the probability that certain symptom and activity descriptions would be associated with an episode of breathlessness. The results indicated symptomatic judgments based on individualized descriptors are subject to errors in logic and probability. Additionally, the results support the premise that experience with a symptom alters an individual's judgments concerning it.

The second aim focused on cognitive representations and their associated influence on the perceptual analysis of breathlessness intensity by testing if the use of a typical cognitive symptom pattern (prototype) or specific remembered symptom instance (exemplar) of breathlessness influenced the determination of symptom intensity or response sensitivity (RS). Magnitude estimation techniques were used to evaluate judgments based on different (prototypes and exemplars) cognitive representations of intensity, using airflow resistance as a stimulus for breathlessness. The results demonstrated a decrease in sensitivity with a prototype and increased RS with an exemplar. This supports that judgments of breathlessness RS vary according to the cognitive representation used.

The final aim tested whether cognitive prototypes of symptoms are present with breathlessness and whether these produce different patterns of response. Assuming the existence of a symptom prototype for breathlessness, the study tested whether the responses to two different but symmetrical statements about breathing status differed based on amount of experience with the symptom. The results demonstrated asymmetrical differences between groups and stimuli used supporting the existence and influence of a symptom prototype.

Taken together the results suggest individuals make rational (experience-based judgments) versus logical (probability based) decisions concerning their symptoms. Cognitive representations of the symptomatic experience were found to influence judgments of intensity. Cognitive information about symptoms exists in the form of a symptom prototype.