New ways to understand aroma perception

Orthonasal or retronasal presentation of odorants evokes different responses. To study this phenomenon in depth, a stimulation technique has been developed that allows ortho- or retronasal presentation of chemosensory stimuli, the release of which is precisely controlled. Based on this technique studies have been conducted using psychophysical, electrophysiological, and imaging techniques. In conjunction with clinical data the results clearly suggest that there are differences in the perception of ortho- and retronasal stimuli. The basis for this phenomenon may be found in ideas by Mozell and colleagues with regard to odorant absorption across the mucosa which may determine activation of the olfactory epithelium.