1 1 Symposium Chemosensory Receptors Satellite DEVELOPMENT ...

189 Poster Multimodal, Chemosensory Measurement,Psychophysical, Clinical Olfactory, and TrigeminalASPARAGUS MALODOR IN URINE—A TRUEPOLYMORPHISM?Pelchat M. 1 , Bykowski C. 1 , Izbicki E. 1 , Reed D. 1 1 Monell ChemicalSenses Center, Philadelphia, PAIt has long been recognized that urine from some individuals whohave eaten asparagus smells like vegetable soup or rotten cabbage.Previous authors have suggested that there are individual differences inproduction of the malodor (e.g. Alison & McWhirter, 1956) or thateverybody produces the odor, but some are insensitive to it (e.g. Lisonet al., 1980). We asked: Are there individual differences in perceptionof asparagus malodor in urine?; Are there individual differences in theproduction of asparagus malodor in urine?; Are there both nonproducersand non-perceivers? 37 adults served as urine donors on twoseparate days. On one day, they ate roasted asparagus and on the otherday they ate bread. They gave a urine sample right before and two hoursafter each snack (4 samples, total). 31 adults were sensory evaluators.Urines from a single donor were evaluated in each session. Evaluatorsperformed a two-alternative forced choice in which their task was toidentify (by smell) the after-asparagus urine (AAU). The AAU wascompared to the before-asparagus urine and the after-bread urine fromthe same donor. We found evidence for individual differences in bothperception and production of asparagus malodor in urine, but at lowerlevels than previously reported: 2/31 evaluators were not able todistinguish the AAU from other samples at a better than chance leveland an additional 2/31 were accurate significantly less of the time thanwere other evaluators. All evaluators with poor discrimination hadotherwise normal olfactory function. For 2/37 urines, the evaluatorswere not able to distinguish the AAU from other samples at a betterthan chance level.190 Poster Multimodal, Chemosensory Measurement,Psychophysical, Clinical Olfactory, and TrigeminalWORKING MEMORY FOR ODORSOlsson M.J. 1 , Jonsson F.U. 1 , Moeller P. 2 1 Psychology, UppsalaUniversity, Uppsala, Sweden; 2 Food Science, Sensory Science, RoyalVeterinary and Agricultural University, Fredriksberg C, DenmarkLittle is known about working memory for odors. Dade et al. (2001)compared working memory for odors and faces in a two-back samedifferenttask and found similar levels of performance. Because theodorants in their study were highly identifiable odorants, verbal codingis likely to have supported the memory performance. In our study, usinga similar two-back same-different task, we compared odors that couldbe verbally described to a variable degree. Twenty-two paid participants(16 women), with a mean age of 28.09 (SD = 9.17) judged a series of36 odors. The probability of an odor on trial n to be same as the one ontrial n-2 was .33. Complementary judgments of the odorants´ perceivedintensity, familiarity and verbal category were also required.Preliminary results indicate that memory performance varied with boththe level of familiarity and the level to which the odor could beverbalized, with higher levels yielding higher memory performance.Familiarity and verbalisation on trial n and n-2 were equally importantfor memory performance. (VR-HS:2005-1779)191 Poster Multimodal, Chemosensory Measurement,Psychophysical, Clinical Olfactory, and TrigeminalTHE INHIBITION OF STRESS—ODOR CONDITIONINGMaute C. 1 , Sitvarin L. 1 , Petrova M. 1 , Dalton P. 1 1 Monell ChemicalSenses Center, Philadelphia, PAOdors, especially novel ones, are often readily associated withpeople, places and even emotional states. In a series of studies, we havebeen investigating the ability of odors to acquire such learnedassociations to either positive or negative emotions. In the presentstudy, we evaluated the degree to which a negative association betweenan odor and a stressor could be prevented by simply pre-exposing theindividuals to the odor while they were in a non-stressful or relaxingstate. Using a latent inhibition paradigm, individuals were exposed togalbanum on three occasions. On the first two occasions, the odor waspaired with either a stressful public speaking and mathematical task or anon-stressful slideshow. On the final session, individuals were merelyre-exposed to the odor while measures of autonomic arousal andsubjective health and well-being reports were obtained. Individualswho experienced the odor in the non-stressful condition first exhibitedlower levels of autonomic arousal and fewer adverse symptoms in thetest session than did individuals whose first odor experience occurredduring the stressful condition. If novel or salient odors that are likely tobe experienced under stressful or dangerous conditions can be identifiedprior to that event, the findings suggest that the ability of these odors toacquire and potentiate conditioned responses can be reduced by preexposureunder non-stressful conditions. This technique could be usefulfor minimizing the persistence of odor-elicited memories and adverseresponses that are often experienced by disaster relief workers, militarypersonnel and other individuals. Supported by DOD Grant 17-01-1-0782192 Poster Multimodal, Chemosensory Measurement,Psychophysical, Clinical Olfactory, and TrigeminalADVERSE EFFECT OF AIR POLLUTION ON OLFACTORYDETECTION OF A CONTAMINATED FOOD BY RESIDENTSOF MEXICO CITYHudson R. 1 , Guarneros M. 2 , Martínez-Gómez M. 3 , Distel H. 4 1 UnivNacional Autónoma de México, Mexico City, Mexico; 2 Univ NacionalAutónoma de México, Mexico; 3 Centro Tlaxcala Biol Conducta, UnivAutónoma de Tlaxcala, Mexico; 4 Univ München, Munich, GermanyRecently we reported that residents of Mexico City (MC; high airpollution) are poorer in detecting, describing and discriminating odorsof beverages than residents of the state of Tlaxcala (Tx; low airpollution). Here we ask if air pollution also affects performance on areal-life task - detecting contamination of a common food. Healthy nonsmokers18-30 years old (MC n = 30, Tx n = 30, equal numbers of menand women) were presented with odorants in squeeze bottles. Whentested with ascending concentrations of stimuli in a 3-way oddballparadigm, Tx subjects detected the odor of orange drink (Tang, Kraft),milk (Nido, Nestlé), and dimethyldisulfide (D) at significantly lowerconcentrations than MC subjects. When presented with milk in itscommercially recommended concentration but mixed with increasingconcentrations of D (a component of "off" milk), Tx subjects detectedthe presence of D and provided descriptions and negative hedonicjudgements at significantly lower concentrations than MC subjects.Also, while Tx subjects began to respond negatively to D at the samelow concentration whether presented alone or in milk, MC subjects firstresponded negatively to it in milk at significantly higher concentrations,that is, detection of D was masked by milk odor to some extent in MCbut not in Tx subjects. Thus, air pollution may affect an olfactoryfunction as basic as judging the edibility of foods.48