Dissociation of the neural correlates coding stimulus intensity and perception of capsaicin urge-to-cough in humans

Abstract

Inhalations of capsaicin are associated with increasing ratings of urge‐to‐cough. We hypothesised that brain regions involved in urge‐to‐cough intensity discrimination would show increased activation at higher compared to lower capsaicin concentrations. Functional brain images were acquired with a Siemens 3T scanner from healthy subjects (n=16) during repeated 18s blocks of inhalation via nebuliser of saline, a low concentration or a high concentration of capsaicin. General linear modelling was used to identify variance in signals associated with inhalation events, and contrasts were generated to identify capsaicin intensity‐dependent activation. Capsaicin challenges produced activations in ..