Ž . International Journal of Psychophysiology 36 2000 147155 Assessment of intranasal trigeminal function Thomas Hummel  Department of Otorhinolaryngology, Uni  ersity of Dresden, Fetscherstr. 74, 01307 Dresden, Germany Received 4 July 1999; received in revised form 5 October 1999; accepted 12 October 1999 Abstract Intranasal trigeminal function is more and more understood as an integral part of human chemosensory perception. Sensations like burning, stinging, warmth, coolness, or itching are produced by almost all odorants so that they can be perceived by anosmics. Electrophysiological responses to trigeminal stimuli allow the specific assessment of trigeminally mediated information at different levels of processing including the periphery or the cortex. Information regarding the localization of these processes can be derived from magnetoencephalographic recordings or functional imaging data. When using these techniques in combination with psychophysical measures, it seems to be possible to specifically describe how and where the processing of irritation takes place, how it may interact with olfactory mediated sensations, and how it is modulated, e.g. by environmental influences or analgesic drugs.  2000 Elsevier Science B.V. All rights reserved. Keywords: Pain; Event-related potential; Irritation; Nasal; Olfaction; Interaction 1. Introduction Measurement of intranasal trigeminal function has received increasing attention throughout the recent decade. It is more and more understood as an integral part of human chemosensory percep- tion. Sensations like burning, stinging, warmth, coolness, or itching are produced by almost all  Tel.: 49-351-458-4189; fax: 49-351-458-4326. Ž . E-mail address: thummel@rcs.urz.tu-dresden.de T. Hummel odorants so that they can be perceived by Ž . anosmics Doty et al., 1978 . 2. Characteristics of trigeminal excitation When compared to the multitude of different odors mediated by the olfactory system, the trigeminal nerve mediates a relatively limited spectrum of sensations. Thus, it appears that this system could be approached easily. However, trigeminally mediated sensations are complicated 0167-876000$ - see front matter  2000 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 1 6 7 - 8 7 6 0 99 00108-7