title: The impact of harmfulness information on citric acid induced cough and urge-to-cough.
abstract: OBJECTIVE
  The cough reflex is an automatic protective reflex, which can be modulated by conscious effort or other forms of top-down control. In this experiment, we investigated whether information about harmfulness of a cough-inducing substance would augment cough reflex sensitivity and associated urge-to-cough.
  
  
  METHODS
  Healthy participants (N = 39) were randomized to receive information that they were to inhale a harmless substance (natural citric acid), or a potentially harmful substance (a potent agro-chemical acid). Using dosimeter-controlled inhalations, the dose of citric acid eliciting at least three coughs (C3) was determined. Next, participants received 4 blocks of randomized presentations of citric acid at the C3 dose, a sub-threshold dose of citric acid and saline control.
  
  
  RESULTS
  C3 was reached for 27/39 participants, and C3 thresholds were not influenced by harmfulness information. During repeated citric acid presentations, framing the cough-inducing substance as a potentially harmful chemical resulted in a greater urge-to-cough compared to information framing it as natural citric acid (p < .01). The experimental manipulation did not influence cough frequencies.
  
  
  CONCLUSIONS
  Our findings show that harmfulness information influences urge-to-cough, corroborating the role of cortical mechanisms in modulating the urge-to-cough and suggesting that cognitive manipulations may contribute to cough treatment.
authors: Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium. Electronic address: thomas.janssens@ppw.kuleuven.be.
authors: Thomas
authors: T
authors: Janssens
authors: Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium.
authors: Sarah
authors: S
authors: Brepoels
authors: University Hospitals Leuven, KU Leuven (University of Leuven), Leuven, Belgium.
authors: Lieven
authors: L
authors: Dupont
authors: Health Psychology, KU Leuven (University of Leuven), Leuven, Belgium.
authors: Omer
authors: O
authors: Van den Bergh
mesh_terms: D000280:Administration, Inhalation; D019343:Citric Acid / Q000008:administration & dosage / Q000009:adverse effects*; D003371:Cough / Q000139:chemically induced* / Q000523:psychology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D019359:Knowledge; D008297:Male; D012018:Reflex / Q000187:drug effects*; D013147:Spirometry; D055815:Young Adult
chemical_list: D019343:Citric Acid
keywords: Citric acid; Cough; Environmental exposure; Environmental intolerance; Perceived harmfulness; Urge-to-cough