Source Emission Odor Measurement by a Dynamic Forced-Choice Triangle Olfactometer

Dravnieks, Andrew; Prokop, William H.

doi:10.1080/00022470.1975.10470045

Cited by 54 publications

(32 citation statements)

References 4 publications

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“…In a number of established triangular method applications (e.g., Dravnieks & Prokop, 1975), in each trial two physically weak (or blank) stimuli plus one stronger one are presented under the instruction to select the odd stimulus. The present experiment justifies the recommendation that all six types of triangles be used, or the instruction should be modified so that the subject is requested to select the strongest stimulus.…”

Section: Resultsmentioning

confidence: 99%

Three-stimulus procedures in olfactory psychophysics: An experimental comparison of Thurstone-Ura and three-alternative forced-choice models of signal detection theory

Frijters

1980

Perception & Psychophysics

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The experimental differences between the triangular method and three-alternative forcedchoice(3-AFC) signal detection theory procedure are briefly reviewed, and the conditions to be met for a valid application of the respective procedures under the Thurstone-Ura and 3-AFC models are described. The assumptions of both of these unidimensional probabilistic models are given, and the functions relating the probability of a correct response to 0, a parameter of sensory stimulus distance, are specified. Since the two models both contain 0, the hypothesis of invariability of this parameter with the triangular method and the 3·AFC procedure was tested using olfactory stimuli. This hypothesis was strongly confirmed, since the functions relating 0 to the logarithm of the ratio of the physical stimulus values were virtually identical for the two methods and their concomitant models. The results are important not only for the field of olfactory psychophysics; they also have Wider methodological and psychophysical interest. The bias against the middle stimulus of a triangle in the triangular method observed when olfactory stimuli are used can be explained as the resultant of sensory adaptation. Finally, some practical implications of the present results for application of the triangular method are discussed.

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Section: Resultsmentioning

confidence: 99%

Three-stimulus procedures in olfactory psychophysics: An experimental comparison of Thurstone-Ura and three-alternative forced-choice models of signal detection theory

Frijters

1980

Perception & Psychophysics

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“…Olfactometer for measurement of thresholds [74,75]. Both types of olfactometers found an important application in the measurement of environmental odors (e.g., [76]).…”

Section: A) Static Olfactometrymentioning

confidence: 99%

Chemical Sensing in Humans and Machines

Cometto‐Muñiz

2002

Handbook of Machine Olfaction

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Chemosensory detection of airborne chemicals by humans is accomplished principally through olfaction and mucosal chemesthesis. Odors are perceived via stimulation of the olfactory nerve (CN I) whereas nasal chemesthetic sensations (i.e., prickling, irritation, stinging, burning, freshness, piquancy, etc), grouped under the term nasal pungency, are mediated by the trigeminal nerve (CN V). Airborne compounds elicit odor sensations at concentrations orders of magnitude below those producing pungency but the physicochemical basis for odor and 3 pungency potency of chemicals, either singly or in mixtures, is far from being understood. The sensitivity of the sense of smell often outperforms that of the most sophisticated chemicoanalytical methods like gas chromatography and mass spectrometry. Still, the combined used of these techniques with human odor detection (i.e., olfactometry) has proved an invaluable tool to understand the chemosensory properties of complex mixtures such as foods, flavors, and fragrances. 1) Human chemosensory perception of airborne chemicalsHumans detect the presence of volatile organic compounds (VOCs) in their surroundings principally through their senses of olfaction and "chemesthesis" [1,2]. The latter is also known as the "common chemical sense" [3,4]. Activation of the olfactory nerve (CN I) produces odor sensations. Chapter 3 describes the biological basis of this chemosensory pathway. Activation of chemoreceptors on the trigeminal nerve (CN V) innervating the face mucosae produces chemesthetic responses (see, for example, [5]). These responses evoked in the nose include stinging, piquancy, burning, freshness, tingling, irritation, prickling, and the like. All these nasal sensations can be grouped under the term nasal pungency [6]. Chemesthetic responses to airborne VOCs can also be produced in the ocular, oral, and upper airway mucosae, where they are referred to as eye, mouth, and throat irritation. In the case of the back of the mouth and the throat, other nerves, such as the glossopharyngeal (CN VIII) and vagus (CN X), are also stimulated by airborne VOCs and contribute to perceived irritation.In this chapter we will focus on human smell and nasal chemesthesis. We will review psychophysical studies performed on both sensory modalities addressing the possible basis for the odor and irritation potency of VOCs. We will also summarize various techniques that combine the power of the human nose with that of chemical-analytical instruments, such as gas chromatography and mass spectrometry, to quantify the chemosensory activity of volatile chemicals and to help understand better the characteristics of human chemosensory perception. 2) Nasal Chemosensory DetectionOdor thresholds represent an important biological characteristic of airborne chemicals.Nevertheless, compilation of such values [7][8][9] show an extreme variability for any particular substance, even after attempting to standardize the values reported in different sources [10]. This scatter severely limits the practical applicatio...

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“…Since the strongest stimulus is odorant-saturated air -the concentration of which may be calculated or looked up from tables -and the other stimuli are fixed dilutions (on a volume basis) of that vapor saturated stream, actual concentrations are simple to compute. Triangle Olfactometer for measurement of thresholds (Dravnieks & Prokop, 1975;Dravnieks, Prokop, & Boehme, 1978). This instrument consists in six sniffing stations, each with three identical sniffing nozzles.…”

Section: Stimulus Control and Measurementmentioning

confidence: 99%