Vision and smell

Yes, I know that if we strictly immobilize a subject s eyeballs by injecting the eye musculature with curare, the subject will soon lose articulate visual experience. So in principle, someone might protest, there is no spatial phenomenological difference between vision and smell. But (i) we have to use an invasive and toxic drug, thus disrupting the normal phenomenology of vision, and (ii) it is unclear that what "experience" remains is properly called vision at all. 

G-protein receptor systems are widespread in living systems. They are found in many animals and microbes. Both vision and smell in humans depend on G-proteins (Campbell et al., 1999), and glucagon receptors use the system to produce a second messenger called cyclic AMP (cAMP). Receptors for epinephrine, angiotensin, endorphins, and acetylcholine also use this G-protein second messenger mechanism (Sleight and Lieberman, 1995). 

Flavor has been defined as a memory and an experience (1). These definitions have always included as part of the explanation at least two phenomena, ie, taste and smell (2). It is suggested that in defining flavor too much emphasis is put on the olfactory (smell) and gustatory (taste) aspects (3), and that vision, hearing, and tactile senses also contribute to the total flavor impression. Flavor is viewed as a division between physical sense, eg, appearance, texture, and consistency, and chemical sense, ie, smell, taste, and feeling (4). The Society of Flavor Chemists, Inc, defines flavor as "the sum total of those characteristics of any material taken in the mouth, perceived principally by the senses of taste and smell and also the general senses of pain and tactile receptors in the mouth, as perceived by the brain" (5). 

Sensations interpreted as pain, including burning, aching, stinging, and soreness, are the most distinctive forms of sensory input to the central nervous system. Pain serves an important protective function because it causes awareness of actual or potential tissue damage. Furthermore, it stimulates an individual to react to remove or withdraw from the source of the pain. Unlike other forms of sensory input, such as vision, hearing, and smell, pain... 

Morgenstern et al reported on over 200 workmen in an American chemical plant making H during World War II, focusing on 10 case histories that illustrated the immediate and delayed effects of daily exposure to small quantities of H vapor. Exposure for 3 wk. to 6 mo ed these men to the dispensary for treatment of respiratory distress. Typically, a man developed some or all of the following symptoms red eyes, photophobia, lacrimation, impaired vision, blepharospasm, loss of taste and smell, nosebleed, sore throat, chest pain, wheeting, and dyspnea. After several such occurrences, a worker was removed from further contact with H. 

The effects of 2C-B are unpredictable and can be radically violent. It is a hallucinogen that produces euphoria and heightened sensual awareness, including vision, hearing, smell, and touch. Low doses of 4-6 mg make the user become passive and relaxed. High doses... 

This second experiment with predator odors deals with day-active mammals whose behavior can be observed directly and readily. Small mammals snch as sqnirrels are prey to many predatory birds and mammals. Vigilance vis-a-vis predators encompass all major senses smell, vision, and hearing. In the chemical sphere, predators leave signals from scent marks, droppings, and nrine in the environment. Sqnirrels as typical rodents have a keen sense of smell capable of detecting snch predator odors and extracting information snch as how recent the sign is. 

G-protein-coupled receptors (GPCRs), also known as seven transmembrane receptors (7TMs), are the largest known superfamily of proteins. They are involved in all types of responses to stimuli, from intercellular communication to the senses of vision, taste, and smell. They respond to diverse ligands ranging from photons (e.g., rhodopsin. Fig. 1) to small molecules (e.g., binding of epinephrine to the f52-adrenergic receptor) and... 

The editors have raised several good questions about this impressionistic claim, and at least three qualifications are required. First, it may be that vision furnishes not more total information but only more immediately usable information. Second, I am speaking of normal (20—20) human vision and normal human olfaction, unaided by instruments. (Suitably fantasized instruments, of course, could change any estimate of amount of information.) Third, smell has the power as sight does not to detect and possibly identify visually hidden sources. 

Most mammals use about 700-800 different types of olfactory receptor proteins in their noses. Humans, chimpanzees, gorillas, orangutans and rhesus macaques use only about half that number. Interestingly, these species are the only animals to possess colour vision and so it would seem that there has been an evolutionary trade-off between smell and colour vision. The rate of loss of olfactory receptor genes is higher in humans than in the other primates, indicating our increased dependence on vision rather than smell (Gilad et al., 2003). 

Biosensors may be key to advancing the capabilities of robotics. Advanced biosensors able to carry out functions such as neural stimulation, vision, hearing, tasting, and smelling may be integrated into robotic control devices for a wide variety of consumer products. For example, taste biosensors could standardize food flavor use, and optical and audio biosensors could be used to control production lines, home appliances, security systems, or automatic pilots in motor vehicles. 

Man is blessed with the sense of smell, taste, touch, vision, and hearing. Three of these senses (touch, vision, hearing) are referred to as the physical senses and are used for detection of mechanical, thermal, photic, and acoustic energy. The other two, the chemical senses, are used for the detection of volatile and soluble substances. The stimuli that excite the physical senses can be measured by both physical and psychophysical means. The volatile and soluble substances that excite the chemical senses can be defined but the stimuli caused by these substances can only be measured by psychophysical means.l z For all practical purposes these stimuli cannot be expressed as some unit of energy, instead they have to be expressed in the dimensions of quality, intensity, duration, and like and dis-1 ike. 

Taste and smell are both chanical senses (Tables 6.20.1 and 6.20.2), touch and hearing are mechanical, and vision is electromagnetic in nature. To this list, we could perhaps add the senses of balance, somatic condition, blood chanical composition, and temperature. Some other animals also sense heat (mosquito, pit viper), magnetic fields (many birds), and electrostatic fields (sharks). 

Healthy newborn human infants are endowed with a highly sensitive sense of smell. Moreover, there are documented accounts of olfactory learning during the early postpartum period. In the present chapter, we present a brief overview of the relevant research literature and suggest tentatively that olfactory learning may be facilitated by neurochemical activities associated with labor and delivery, and memory traces of odors learned shortly after birth may be retained more efficiently than early postnatal memories involving other sensory modalities (i.e., vision and audition). 

Test has been conducted for the five varieties of mango fruit only, but can be extended for other fruits where there are reasonable changes in skin color texture occur with maturity. The variations of classification performances with the variation of other factors like changes in ambient light, camera resolution, and distance of the camera were not studied. The study shows that, machine vision based system performance, is closer to the manual experts, where experts judge the mangoes maturity level not only by the skin color but also with firmness and smell. 

Gilbert, A. N., Martin, R. and Kemp, S. E. (1996) Cross-modal correspondence between vision and olfaction The color of smells, American Journal of Psychology, 109, 335-351. 

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