Olfactory Acuity and Automatic Associations to Odor Words Modulate Adverse Effects of Ammonia
- 107 Downloads
Adverse effects of malodorous chemicals in humans are usually described as negative emotional reactions and impaired cognitive performance. Sensory acuity and automatic associations to odor words could influence cognitive processing of chemosensory stimulation and such adverse effects. We hypothesized that adverse effects are amplified in individuals with lower olfactory acuity due to a more automatic and emotional odor evaluation process. In contrast, adverse effects should be attenuated if odor words such as smell automatically activate positive mental associations.
After the assessment of olfactory acuity and automatically activated associations in standardized tests, 37 women were exposed to ascending concentration steps of ammonia (0–10 ppm) in an exposure laboratory for 75 min. Participants rated hedonic valence, intensity, and pungency of ammonia and performed working memory and response inhibition tasks.
Olfactory acuity modulated ratings of hedonic valence and working memory performance: Participants with lower olfactory acuity reported stronger odor unpleasantness and showed impaired performance compared to participants with higher olfactory acuity during the exposure to 10 ppm ammonia. In the lower olfactory acuity group, participants with strong automatic associations between odor words and positive valence rated ammonia at high concentrations to be less pungent than participants with weaker automatic associations.
We conclude that sensory acuity and automatically activated associations modulate chemosensory-mediated adverse effects of ammonia. Beyond established self-report measures, these individual characteristics could help explain differences in environmental odor annoyance.
KeywordsChemosensory distraction Emotion Implicit association test N-Back
This research was supported by the DGUV—German Social Accident Insurance, Berlin, Germany (FF-FP0326). The study sponsor had no influence in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.
The authors would like to thank Nicola Schmidt-Peucker, Eva Strzelec, Michael Porta, and Beate Aust for technical assistance and Leah Boccaccio for proofreading.
Compliance with Ethical Standards
Conflict of Interest
Marlene Pacharra, Michael Schäper, Stefan Kleinbeck, Meinolf Blaszkewicz, and Christoph van Thriel declare that they have no conflict of interest.
All procedures performed were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments.
Informed consent was obtained from all individual participants included in the study.
- Blanes-Vidal V, Nadimi ES, Ellermann T, Andersen HV, Lofstrom P (2012) Perceived annoyance from environmental odors and association with atmospheric ammonia levels in non-urban residential communities: a cross-sectional study. Environ Health 11:27. doi: 10.1186/1476-069X-11-27 CrossRefGoogle Scholar
- Hummel T, Sekinger B, Wolf SR, Pauli E, Kobal G (1997) ‘Sniffin’ sticks’: olfactory performance assessed by the combined testing of odor identification, odor discrimination and olfactory threshold. Chem Senses 22:39–52. doi: 10.1093/chemse/22.1.39
- Hummel T, Kobal G, Gudziol H, Mackay-Sim A (2007) Normative data for the “Sniffin’ Sticks” including tests of odor identification, odor discrimination, and olfactory thresholds: an upgrade based on a group of more than 3,000 subjects. Eur Arch Otorhinolaryngol 264:237–243. doi: 10.1007/s00405-006-0173-0 CrossRefGoogle Scholar
- Juran SA, van Thriel C, Kleinbeck S, Schäper M, Falkenstein M, Iregren A, Johanson G (2012) Neurobehavioral performance in human volunteers during inhalation exposure to the unpleasant local irritant cyclohexylamine. Neurotoxicology 33:1180–1187. doi: 10.1016/j.neuro.2012.06.014 CrossRefGoogle Scholar