The study with its three-component research plan was renewed in fiscal year 1997. Component 1 strengthened understanding of the psychologic and physiologic correlates of perceptual ability. A positive association was expected between perceptual accuracy and a) intelligence; b) attention; c) symptom focus; d) systemic steroid use; and e) predominantly large airway or mixed airway involvement. Component 2 explored the relationship between chemosensitivity and resistive-load perception in high risk pediatric asthma patients. It was hypothesized that, compared to other asthmatics and controls, adolescents who had near fatal asthma attacks a) had higher thresholds for detecting resistive loads; b) had a decreased response to progressive isocapneic hypoxia; and c) had a smaller increase in respiratory drive during progressive hypercapnia. Component 3 characterized the family and self-management patterns moderating variables between perception and morbidity. It was hypothesized that a) symptom perception interacted with family asthma management in relation to asthma morbidity b) poor symptom perception was associated with worse medication compliance; and c) better family functioning was related to better perception and lower functional morbidity. Methodologic approaches included a naturalistic clinical accuracy protocol; laboratory studies using a computerized resistive-loading apparatus to determine perceptual thresholds; a chemosensitivity protocol investigating drive; family assessment interviews, and computerized metered dose inhaler technology to assess compliance with asthma medications.