ABSTRACT
The chemosensory systems of taste, smell, and chemical irritation all discriminate among strengths and qualities of chemical stimuli. However, the three chemosensory systems utilize distinct neural pathways, have receptors that are distributed differently, and provide distinct information about chemical stimuli (Frank and Rabin, 1989). Strategies for measuring taste function reflect its special characteristics. The sense of taste, a special visceral chemical sense with receptors located within the oral cavity, discriminates chemical features that indicate nutrient or poison (Bartoshuk, 1991; Frank et al., 1992; Scott and Mark, 1987). It is generally accepted that most taste perceptions are sweet, salty, sour, or bitter. “Nontraditional” tastes (Hettinger et al., 1990) often are flavor sensations derived from retronasal stimulation of olfactory receptors (see Chapters 10,22, and 44). The savory umami quality may be an exception (Hettinger et al., 1996; Yamaguchi, 1991). In contrast, smells are more diverse, defying consistent perceptual categorization (Beets, 1971), and irritations may form one perceptual category (Green and Lawless, 1991).
