Polysemy and metaphor in perception verbs: a cross-linguistic study
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PhD-Thesis-99
5.1.1.4. Smell
The stimulus for smell consists of volatile molecules or vapours, which reach the olfactory cavity either through the nostrils or through the mouth. This is represented by the property > in the following section. Although these molecules are in contact with our noses, it is interesting to notice that PRs do not perceive the sense of smell as one that requires contact. In fact, the sense of smell has been classified – together with hearing – as a non-contact sense, because it “often signal[s] the presence of something at a distance from the perceiver” (Viberg 1984: 148). This is represented by the property > in the following section. These odour molecules are contained in the air that we need to inhale in order to breathe; as a result we smell all the time, without being conscious of it all the time. This is represented by the property > in Section 5.2. Although odour perception is not as accurate as that of the other senses and rather dull if compared with that of other species such as the dog (Moulton 1976), the human nose is very sensitive. It is capable of detecting odours as faint as ethyl mercaptan in concentrations as minute as 1 part per 50 billion parts of air (Sekuler and Blake 1994: 426). Despite this ability to detect odours, the identification and naming of the odour itself is difficult. This difficulty is termed the ‘tip of the nose’ phenomenon by some researchers (Lawless and Engen 1977). Later in the analysis, these two characteristics are represented by the properties > and >. Odour sensitivity varies a great deal from odour to odour; it depends on other factors such as age and gender of the PR, the concentration level of odorous molecules, and the distance between the PR and the object that emits the odour (Sekuler and Blake 1994). The closer the PR is to the source of odour, the stronger the perception of the odour is, and therefore, the easier its detection. This characteristic is represented by the property > in Section 5.2. The two nostrils work in alternating turns, a phenomenon called ‘nasal cycle’, which seems to correspond to an increase in brain activity in the hemisphere B. Iraide Ibarretxe-Antuñano Polysemy and metaphor in perception verbs 141 contralateral to the dominant nostril (Werntz et al. 1987). The olfactory receptor cells sit on the olfactory epithelium in the nasal cavity. These cells, between 6 and 10 million in the human nose, are different from other sensory cells such as photoreceptors, and hair cells. On the one hand, they all have the paraphernalia of neurones (cell bodies, short dendrites, and long axons); as a consequence, they are able to carry out two different tasks: to transform chemical stimulation into neural impulses and to carry those impulses directly to the brain. On the other hand, olfactory neurones are capable of reproducing; olfactory cells live for about 5 to 8 weeks, and when they die they are replaced by new ones (Graziadei and Monti Graziadei, 1988). Each olfactory cell has minuscule filaments, called cilia, extending from the olfactory knobs. These cilia extend beyond the surface of the epithelium, into the watery mucus that bathes the epithelium. The proteins contained in the cilia – the olfactory binding proteins – comprise the actual molecular receptors that grasp for fragrance molecules or portions of them. Each of the sensory nerves has a long filament, the axon, on the end opposite to the olfactory knob. This axon connects with other nerve cells in the brain. The information about the odour pattern is conveyed from the olfactory bulbs to other regions of the brain, such as the hypothalamus and other limbic system structures. Here it is processed in order to co- ordinate and manage our abilities to learn, to remember, to think, to respond, and to contemplate. The limbic system plays an important role in emotional reactions (Sekuler and Blake 1994: 444) and this may be a reason that explains why smells (and tastes) vary greatly from person to person. The property > in Section 5.2.2 reflects this possibility. Smell is nature’s oldest and most primitive sense (see Olfactory Research Fund 1996). When scattered cells that lived in water first inhabited the world, the only sense that was available to them was ‘smell’, on which they depended to detect chemicals. As animals evolved, so did the nervous system, which developed a smell brain that helped to locate food, identify mates and detect enemies. Our sense of smell still uses similar regions of the brain as in the beginning, as the limbic system, although this has expanded its duties too to become responsible for our emotions, sexuality, memory and creativity. B. Iraide Ibarretxe-Antuñano Polysemy and metaphor in perception verbs 142 Download 1.39 Mb. Do'stlaringiz bilan baham: |
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