title: Time-course of trigeminal versus olfactory stimulation: evidence from chemosensory evoked potentials.
abstract: Habituation of responses to chemosensory signals has been explored in many ways. Strong habituation and adaptation processes can be observed at the various levels of processing. For example, with repeated exposure, amplitudes of chemosensory event-related potentials (ERP) decrease over time. However, long-term habituation has not been investigated so far and investigations of differences in habituation between trigeminal and olfactory ERPs are very rare. The present study investigated habituation over a period of approximately 80 min for two olfactory and one trigeminal stimulus, respectively. Habituation was examined analyzing the N1 and P2 amplitudes and latencies of chemosensory ERPs and intensity ratings. It was shown that amplitudes of both components - and intensity ratings - decreased from the first to the last block. Concerning ERP latencies no effects of habituation were seen. Amplitudes of trigeminal ERPs diminished faster than amplitudes of olfactory ERPs, indicating that the habituation of trigeminal ERPs is stronger than habituation of olfactory ERPs. Amplitudes of trigeminal ERPs were generally higher than amplitudes of olfactory ERPs, as it has been shown in various studies before. The results reflect relatively selective central changes in response to chemosensory stimuli over time.
authors.affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany; Department of Psychology (Biological Psychology, Clinical Psychology, and Psychotherapy), University of Würzburg, Germany. Electronic address: elena.flohr@uni-wuerzburg.de.
authors.forename: Elena L R
authors.initials: EL
authors.lastname: Flohr
authors.affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany; Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands; Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Sanne
authors.initials: S
authors.lastname: Boesveldt
authors.affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Haehner
authors.affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany.
authors.forename: Emilia
authors.initials: E
authors.lastname: Iannilli
authors.affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Sinding
authors.affiliation: Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hummel
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002245:Carbon Dioxide / Q000494:pharmacology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006185:Habituation, Psychophysiologic; D006801:Humans; D008297:Male; D009812:Odorants; D011930:Reaction Time / Q000187:drug effects; D012903:Smell / Q000502:physiology*; D013268:Stimulation, Chemical; D013447:Sulfites / Q000494:pharmacology; D014276:Trigeminal Nerve / Q000502:physiology*; D055815:Young Adult
chemical_list: D013447:Sulfites; D002245:Carbon Dioxide; C042345:hydrogen sulfite
keywords: Chemosensory event-related potentials; Habituation; Olfaction; Trigeminal stimulation