Semantic-free scaling of odor quality.
ABSTRACT The validity of the odor quality reports given by naive human subjects is often questionable. On the one hand, social conventions can influence the labeling of odorants, especially those that have putrid or uncommon odor qualities, and on the other, semantic differences exist for odor descriptors among individuals. We are interested in the individual differences in the quality reports elicited by two nominally putrid odorants, androstenone (AND) and pemenone (PEM). Here we sought to establish empirical support for the individual differences previously obtained in studies of their odor quality, using a nonverbal, semantic-free method of classification. Undergraduate volunteers sniffed a moderate concentration (390 microM) of PEM, rated its intensity, and provided a verbal odor descriptor. The subjects were then classified as PEM osmic (n = 42) if the quality report was putrid (rancid, urinous, sweaty), allosmic (n = 23), if the quality was nonputrid, and anosmic (n = 39) if no odor was detected. The subjects then sorted 15 odorants matched for intensity, five selected from each of three nominal odor quality types, into as many odor groups as they wished, as long as each group contained all of the compounds with similar odors. The number of times each odorant was paired with another was used as data for an independent multidimensional scaling with ALSCAL, for each class of subject. Three-dimensional solutions showed that this nonverbal, semantic-free scaling method produced odor classifications consistent with those found when each class of subject reported odor qualities from a defined list of quality descriptors. Cluster analysis of the MDS coordinates revealed that these solutions also retained the individual odor quality differences thought to be characteristic of osmic, allosmic and anosmic subjects.
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ABSTRACT: Introduction Sniffin’ Sticks Test (SST) is a complex smell test, enabling the diagnosis of various aspects of olfactory sensitivity. It is one of the most popular tools for olfactory testing all over the world; however, so far it has not been commonly used in Poland. Aim The presented study had the following aims: assessment of the applicability of the SST in Poland, adaptation of the identification subtest, normalization of the whole battery and comparison of the Polish results to the norms in the original tool. Materials and methods We tested olfactory sensitivity of 281 healthy volunteers aged 18–87 years. We used the full version of the SST (threshold, discrimination and identification subtests). Results The results of the presented study are the modified version of the identification test response questionnaire and clearly defined normative values for the Polish people of different ages. Normative values and results in Poland were not significantly different from the previously reported findings for the original, German tool. Additionally, consistent with previous reports, olfactory sensitivity of the eldest group of the Polish people was lower than performance in younger age groups. Conclusions The presented findings suggest that the adapted version of the Sniffin’ Sticks Test might be used for both medical and research purposes in Poland.Otolaryngologia polska. The Polish otolaryngology 08/2014;
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ABSTRACT: Decoding the psychological dimensions of human odor perception has long been a central issue of olfactory research. Odor scientists as well as fragrance professionals have tried to establish comprehensive standards for the description, measurement, and prediction of odor quality characteristics. As odor percepts could not be linked to a few measurable physicochemical features of odorous compounds or physiological characteristics of the olfactory system, odor qualities have often been assessed by perception-based ratings. Although they have been applied for more than 5 decades, these psychological approaches have not yielded a comprehensive or generally accepted classification system yet. We assumed that design and methodology of these studies have largely prevented the development of unbiased odor arrangements. To address this issue, we reviewed 28 perception-based classification studies and found that their outcome has been largely determined by 4 influencing factors: 1) interindividual differences in perceptual and verbal abilities of subjects, 2) stimuli characteristics, 3) approaches of data collection, and 4) methods of data analysis. We discuss the effects of each factor in detail and illustrate how odor systems have reflected perceptual qualities as well as the conditions under which these have been assessed.Chemical Senses 01/2013; DOI:10.1093/chemse/bjs141 · 3.28 Impact Factor
Article: Quantification of odor quality.[Show abstract] [Hide abstract]
ABSTRACT: The relationship between odor quality and molecular properties is arguably the most important issue in olfaction. Despite sophistication in the chemical characterization of molecules, accompanying perceptual characterization has had little quantitative usefulness, relying mostly on enumerative description. As a result of weak interest in the topic outside industry and little agreement regarding how to measure quality, the field of olfactory psychophysics has failed to develop a substantial database for odor quality and has offered little help to other researchers, e.g. neurobiologists, in choice of stimuli, interpretation of outcome or testable hypotheses. This review scrutinizes how psychophysicists and others have measured quality and offers criteria for useful techniques. Most measures have had a subjective component that makes them anachronistic with modern methodology in experimental behavioral science, indeterminate regarding the extent of individual differences, unusable with infrahumans and of unproved ability to discern small differences. Techniques based upon performance, rather than on the more common reporting of mental content, offer firmer possibilities for growth. These techniques inevitably tap the discriminative basis of perception. The nonsubjective techniques have high sensitivity, can have counterparts in infrahuman research, are suitable to examine individual differences and yield non-negotiable answers with potential archival value. Discriminative techniques have their limitations, too-principally excess sensitivity that abridges their use to comparisons between similar-smelling stimuli. Research has begun to extend that range and may overcome the limitation. Application of discriminative methods may have the side-effect of shifting focus in structure-activity research from searches for molecular least common denominators that underlie often vague similarity to the search for molecular properties of importance in discrimination of small differences.Chemical Senses 09/2000; 25(4):429-43. · 3.28 Impact Factor