Human Olfactory Perception

Doty, R.L. Gender and Endocrine-Related Influences on Human Olfactory Perception. In H.L. Meiselman and R.S. Rivlin eds. Clinical Measurements of Taste and Smell, p. 377-413. New York MacMillan Publishing Co. 1986. 

For a deeper insight into the mechanism of human olfactory perception, compare Gelperin, A. (2010) in The... 

A first study was designed to assess the effectiveness of three European clinical olfactory tests for characterizing the olfactory abilities of healthy subjects qualified to take part in sensory analysis studies. On the basis of this first study, certain sources of variation in human olfactory perceptions were highlighted and their respective impacts on a number of olfactory tasks were assessed. 

The mammalian olfactory system possesses enormous discriminatory power. It is claimed that humans can perceive many thousands of different odorous molecules, termed odorants. Even slight alterations in the structure of an odorant can lead to profound changes in perceived odor quality. One commonly cited example is carvone, whose L- and D-stereoisomers are perceived as spearmint and caraway, respectively. However, more subtle molecular alterations can also generate striking changes in perception. 

Abstract Sexual orientation influences human olfactory function. Following a brief review of the biological basis of homosexuality, this chapter explores exactly how olfactory function varies as a result of sexual orientation. Three separate areas of research are considered recent studies on the neural processing of social odorants by heterosexuals and homosexuals the influence of sexual orientation on the production and perception of body odours and the influence of female sexual orientation on menstrual synchrony. 

Chen, D. and Haviland-Jones, J. (2000) Human olfactory communication of emotion. Percept. Motor Skill. 91,771-781. 

In mammals, the main olfactory system is the work horse in the perception of odors. Excellent detailed reviews of the mammalian olfactory system are available elsewhere. In brief, the olfactory epithelium is located on a portion of the scroll bones (endoturbinales and posterior part of nasoturbinales F ig. 5.4), in humans it is located about 1 cm beneath the bridge of the nose. Olfactory reception is affected by several factors, such as the size, shape, or wetness of the nasal passages. In the dog, the olfactory membrane extends over 75-150 cm depending on body size, while in humans it is only 2-4cm. It consists of three... 

Enantiomeric compounds differ from one another only in two aspects The chiroptical characteristics (optical rotation) and the speed of their reaction with chiral molecules. The human olfactory organ is also capable of distinguishing chiral molecules. The odor quality and potency of enantiomeric compounds may show considerable differences. Thus, distinct differentiation in odor perception could be observed in the pairs of enantiomeric oxygenated monoterpenoid odorants. " However, the... 

There are good reasons why human beings have failed to develop an ability for olfactory recall compared with other forms of perception. Auditory recall is an essential part of our ability to use sound as a means of communication and language, and visual recall, including our ability to see things as they might be rather than as they are is basic to our purposeful manipulation of objects. 

In this section, aroma science in terms of human interaction will be highlighted. In the first part, the human olfactory system from the biological aspect is summarized. Genetic background in the perception of odor molecules is briefly summarized. Human interaction in terms of aromatherapy is briefly described to end the section. 

Olfaction, like visual and taste perception, is an ancient process. Olfaction plays a role in sexual arousal. The olfactory system in mammals is remarkable with respect to the number of receptors engaged in monitoring odours. There are several thousand hepta-helical G-protein-coupled receptors in the olfactory epithelium and the nasal organ of a dog, and still about 1000 receptors in the corresponding human organs. It has been estimated that nearly 1% of all genes code for olfactory receptors alone. 

Chemical understanding interprets phenomena in terms of the positions and movements of atoms and the forces acting upon them. The Oxford English Dictionary defines phenomenon as "that of which the senses or mind directly takes note an immediate object of perception." This chapter has argued that behavioral performance permits an assessment of what another creature can detect by means of olfaction alone, thus extending the notion of "senses or mind" beyond the realm of the human. The belief that all terrestrial vertebrates share similar olfactory mechanisms implies that these will ultimately prove susceptible to chemical understanding. The confirmation of such understanding will be the ability to archive odors. 

The excitation pattern represents aU olfactory properties of the scent molecule, which are forwarded via the olfactory tract (Tractus olfactorius) into the rhinencephalon and other parts of the brain. The perception is compared with characteristic olfactory impressions in the memory, which finally enables humans to distinguish a diversity of approximately 10,000 scents (Fig. 3.4). [4]... 

Flavor is a combination of taste, sensation, and odor transmitted by receptors in the mouth (taste buds) and nose (olfactory receptors). The stereochemical theory of odor is discussed in the essay that precedes Experiment 16. The four basic tastes (sweet, sour, salty, and bitter) are perceived in specific areas of the tongue. The sides of the tongue perceive sour and salty tastes, the tip is most sensitive to sweet tastes, and the back of the tongue detects bitter tastes. The perception of flavor, however, is not so simple. If it were, it would require only the formulation of various combinations of four basic substances—a bitter substance (a base), a sour substance (an acid), a salty substance (sodium chloride), and a sweet substance (sugar)—to duplicate any flavor In fact, we cannot duplicate flavors in this way. The human possesses 9,000 taste buds. The combined response of these taste buds is what allows perception of a particular flavor. 

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