Chemosensory event-related potentials in man: relation to olfactory and painful sensations elicited by nicotine.

The aim of this study was to investigate the topographical distribution of chemosensory event-related potentials in relation to stimulation with nicotine. The recognition thresholds of 3 different sensations elicited by nicotine (odor, burning, stinging) were determined. Subsequently, 3 concentrations of nicotine were applied which were just above mean threshold for each of the 3 sensations. Subjects rated the intensity of odor, burning, and stinging. Additionally, they tracked the time course of these sensations. Odor and stinging appeared immediately after stimulus onset. Burning started after several seconds. Intensity ratings of burning and stinging increased with rising stimulus concentrations, whereas the odorous sensation was strongest at medium concentrations. After low and medium stimuli largest mean amplitudes were parietally obtained, whereas following stimulation with the highest concentration, amplitudes peaked at Cz.