title: Pupillary responses to intranasal trigeminal and olfactory stimulation.
abstract: The aim of the present study was to investigate whether pupillary responses to odorous stimuli reflect their intensity or hedonic tone. A total of 21 healthy subjects participated in the study. Using a computer-controlled olfactometer, subjects received intranasal stimuli including odors of rose (PEA; 2 concentrations), lemon and rotten eggs, plus the trigeminal irritant CO2 (also at two concentrations). Changes in the pupil diameter were obtained ipsilaterally to the side of stimulus presentation. Both trigeminal and olfactory stimulation produced an increase in pupillary diameter. Latencies for pupillary reaction were fastest for the higher concentration of CO2 and slowest after the presentation of PEA at the low concentration. Response amplitudes were largest in response to stimulation with CO2 at the high concentration, while they were smallest in response to odorous stimulation with PEA. Response latencies decreased with increasing stimulus intensity. No such correlation was found for hedonic ratings and pupillary reactions. Thus, the change in the pupillary diameter indicates differences between stimulus modalities and stimulus strength, but not pleasantness or unpleasantness of the odors.
authors.affiliation: Department of Neurology, University of Dresden Medical School, Dresden, Germany.
authors.forename: Christine B
authors.initials: CB
authors.lastname: Schneider
authors.forename: Tjalf
authors.initials: T
authors.lastname: Ziemssen
authors.forename: Benno
authors.initials: B
authors.lastname: Schuster
authors.forename: Han-Seok
authors.initials: HS
authors.lastname: Seo
authors.forename: Antje
authors.initials: A
authors.lastname: Haehner
authors.forename: Thomas
authors.initials: T
authors.lastname: Hummel
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000502:physiology*; D002245:Carbon Dioxide / Q000494:pharmacology; D004644:Emotions / Q000187:drug effects / Q000502:physiology; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007498:Iris / Q000294:innervation / Q000502:physiology*; D007509:Irritants / Q000494:pharmacology; D008297:Male; D009296:Nasal Cavity / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D009812:Odorants; D009831:Olfactory Mucosa / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D009832:Olfactory Nerve / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D011680:Pupil / Q000502:physiology*; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012201:Reward; D012684:Sensory Thresholds / Q000187:drug effects / Q000502:physiology; D012903:Smell / Q000502:physiology*; D014276:Trigeminal Nerve / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D007509:Irritants; D002245:Carbon Dioxide