title: US-inflation in a differential odor-conditioning paradigm is not robust: relevance for medically unexplained symptoms.
abstract: Reported somatic symptoms without clear relation to physiological processes are studied. A learning paradigm was used with two odors (CSs) and the inhalation of CO(2)-enriched air (US), while measuring symptom levels and respiratory behavior. After paring one odor with the CO(2)-enriched air and the other odor with air, half of the participants received a US-inflation manipulation (information manipulation and enhanced US). Subsequently, all participants received both odors with air (test). A difference between the odor previously paired with CO(2)-enriched air and the odor previously paired with air was found for the symptom measure, US-expectancy ratings, and, to a lesser extent, for respiratory volume. No differences, however, were found between the group receiving the US-inflation manipulation and a group not receiving this manipulation. The results indicate that, despite a successful learning of reported symptoms, US-inflation does not seem to be robust.
authors.affiliation: Research Group for Stress, Health, and Well-being, Faculty of Psychology and Educational Sciences, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium.
authors.forename: Stephan
authors.initials: S
authors.lastname: Devriese
authors.forename: Steven
authors.initials: S
authors.lastname: De Peuter
authors.forename: Ilse
authors.initials: I
authors.lastname: Van Diest
authors.forename: Karel P
authors.initials: KP
authors.lastname: Van de Woestijne
authors.forename: Omer
authors.initials: O
authors.lastname: Van den Bergh
mesh_terms: D019342:Acetic Acid; D000293:Adolescent; D000328:Adult; D000641:Ammonia; D001143:Arousal; D001245:Association Learning; D001364:Awareness; D002245:Carbon Dioxide; D003214:Conditioning, Classical; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000175:diagnosis / Q000523:psychology*; D009812:Odorants; D012718:Set, Psychology; D012903:Smell; D013001:Somatoform Disorders / Q000175:diagnosis / Q000523:psychology*
chemical_list: D002245:Carbon Dioxide; D000641:Ammonia; D019342:Acetic Acid