Sensory perception sensation

Sensory perception is both quaUtative and quantitative. The taste of sucrose and the smell of linalool are two different kinds of sensory perceptions and each of these sensations can have different intensities. Sweet, bitter, salty, fmity, floral, etc, are different flavor quaUties produced by different chemical compounds the intensity of a particular sensory quaUty is deterrnined by the amount of the stimulus present. The saltiness of a sodium chloride solution becomes more intense if more of the salt is added, but its quaUty does not change. However, if hydrochloric acid is substituted for sodium chloride, the flavor quahty is sour not salty. For this reason, quaUty is substitutive, and quantity, intensity, or magnitude is additive (13). The sensory properties of food are generally compHcated, consisting of many different flavor quaUties at different intensities. The first task of sensory analysis is to identify the component quahties and then to determine their various intensities. 

It may be speculated that the actual application of a moisturizer satisfies an atavistic psychological need for physical contact, which is reinforced by the immediate physical effects of the moisturizer. It has been shown that the application of a moisturizer increases the tactile sensations in dry skin, both by lowering the threshold for perception and by allowing better point-discrimination.30 The use of a moisturizer therefore potentially enriches sensory perception. 

Flavor is the complex effect of three components taste, odor, and feeling factors. It is usually associated with the pleasure of savoring food or beverages and has, subsequently, suffered from considerable imprecision in definition. Flavor is a sensation with multidimensional components involving subjective and objective perceptions. The sensory perceptions are both qualitative as well as quantitative and, therefore, can be measured. Webster s New Collegiate Dictionary defines flavor as the ... quality of something that affects the sense of taste,. .. the blend of taste and smell sensations evoked by a substance in the mouth. This definition is correct, but incomplete, and should be redefined to include feeling factors. 

Knowledge begins with sensory impressions. When we look at a star, we integrate the image with our memory of the properties of a star. When we say we hear a bell, what we actually hear is the sound of a bell. What we see or hear is not the object or the sound, but with the effect that the object or sound has on us. Knowledge and ideas are derived from perceptions. Sensations, perceptions and thoughts lead to actions. 

For the panel leader, it means it is important to spend enough time on the selection and the definition of the attributes, so that the subjects are very comfortable in identilying the sensory perceptions and can be quick in selecting the sensation they perceive as dominant during the evaluation. In this way, the number of attributes should also not be too large, say about ten as mentioned before. 

Sensation involves the conversion of physical energy into nerve impulses (e.g., photons are converted into neural signals for vision), but perception involves making a meaningful representation of those signals. This includes all sensory modalities vision (sight), audition (hearing). 

Reviews of taste sensations normally concentrate on four basic tastes - sweet, salty, sour and bitter (7,2) however, other oral sensations can contribute important information to the perceived flavor (3), Examples of stimulants evoking these very different sensory sensations are shown in TABLE I. Studies on the mechaiusms of perception are usually restricted to sensation-specific stimuli however, food flavors represent an interaction among the various sensations. This chapter describes recent... 

While some researchers feel that individual components making up the sensory response need to be characterized (9), others feel that methods dealing with the composite sensation are more appropriate. For this reason methods which do not rely on internal representation of terms have been applied. One such method is multidimensional scaling (MBS), which treats data based on a persons total perception of the dissimilarity between objects.(10)... 

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