Tactile sensation

Flavor. The sensation produced by a material taken into the mouth, perceived principally by the senses of taste and smell, but also by the common chemical sense produced by pain, tactile, and temperature receptors in the mouth. 

The sensation of pain, following injury or disease, in response to a previously non-noxious stimulus is termed allodynia . Tactile allodynia is caused by... 

A century ago, Fick proposed the concept of four primary tastes, namely, sweet, salty, sour, and bitter. It has since been found that taste sensations are not describable by a single collection of discrete primaries. Electrophysiological studies of afierent taste-units in the chorda tympani and glossophyrangeal nerves have revealed that a continuous spectrum of gustation may be based on these four taste elements. Furthermore, the intensities of the tastes that we commonly experience are due not only to gustatory sensations but also to tactile, hot and cold, and, above all, olfactory sensations. The complexities of taste studies are such that, unless one of the taste modalities is singled out for study, there is very little hope of success. 

TACTILE DISTURBANCES Ask "Have you any itching, pins needles sensations, any burning, any numbness, or do you feel bugs crawling on or under your skin " Observation. 

The sensory receptors and spinal tracts that convey these sensations are multiple, and the sensations often reach consciousness, in the parietal lobe, as blends of the primary components. Because of the number of receptors and hence of distinct tactile feelings and blends, they are best lumped together. 

Kittens rely little on olfactory stimuli to attach to the nipples of their mother. Instead, tactile cues are important. The mouth area and the trigeminal projection field mediate these tactile sensations (Blass etal, 1988). 

Chronic use of amphetamine or cocaine can give rise to visual, tactile, olfactory and auditory hallucinations (Miller, 1991 Sims, 1988). Formication is characteristic in which the user experiences the sensation of little animals or insects crawling over the body or just under the skin or sees his body covered in sores or vermin. These hallucinations may lead to delusions of infestation. 

Anaesthesia Loss of feehng or sensation. Although the term is used for loss of tactile sensibihty, or of any of the other senses, it is apphed espedally to loss of the sensation of pain, as it is induced to permit performance of surgery or other painful procedures. [EU]... 

Breslin, P.A. et ak. Psychophysical evidence that oral astringency is a tactile sensation. Chem. Senses 18, 405, 1993. 

Sensory deprivation is a technique, the purposes and results of which I am not sure. Generally it includes earplugs, masks over the eyes, avoidance of tactile sensation or stimulation of skin, and deliberate relaxation, as well as tanks of warm water. Classical and operant conditioning can affect what one likes, dislikes, fears, enjoys, remembers or forgets. 

I tested my tactile sensitivity. I worked my way back to the couch and found Alice. My exploration of the softness of the sweater and the warmth of her flesh was an ecstatic sensual experience. However, it was devoid of sexuality, devoid of passion. While on the couch, the stimulation of touch became less important to me as I began to experience the dichotomous sensation of sinking into the cushions and yet floating slightly above them. 

Like MDMA, recreational users of 2C-B say the drug greatly heightens their appreciation of and sensitivity to music and say that it greatly enhances the enjoyment of dancing. At higher doses (15-20 mg), recreational users report heightened tactile sensations and profoundly altered states of consciousness. 

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. 

In actual fact, tactile sensation over the skin surface is highly dependent on finger pressure. The slow adapting receptors (RufRni and Merkell) probably determine this pressure, which then generates information relative to skin firmness. 

Other chemical sensations associated with the trigeminal ganglion include temperature sensations such as the coolness (35) associated with menthol and the heat associated with capsaisin. Oral sensations elicited by chemical solutions also include tactile sensations such as smooth, dry, or powdery, and such disagreeable sensations as pain. Some of these sensations may represent different degrees of activation of a single system or the activation of several separate systems. 

Astringency is a tactile sensation, which is often described as a puckering, rough or drying mouthfeel. The mechanism of its perception is unknown, although it is probably mediated by touch or mechanoreceptors 4). Chemically, astringents have been defined as compounds which precipitate proteins. For water soluble phenols, this has been reported to require molecular weights between 500 and 3000 daltons (5). 

Sensory neuropathy occurred in a 58-year-old man who had been given up to 2400 mg/day for over 5 months for the treatment of head pain (12). A mild pruritic rash had been present since starting treatment. Neuropathic symptoms included a burning sensation in the legs and hips. After withdrawal, reduced perception of tactile and noxious stimuli and neurogenic bladder dysfunction (with an associated syncopal episode) were recorded. The neuropathy improved over several months. 

In the case of topical gels, a combination of i, K-, and X-carrageenans produces a spreadable gel with acceptable tactile sensation, resulting in drug release that is more likely to follow diffusion kinetics. 

---