Taste
Taste is one of the most common and fundamental of the
senses of
animals. It is the direct detection of
chemical composition, usually through contact with
chemoreceptor cells. Taste is very similar to
olfaction, the sense of smell, in which the chemical composition of an organism's ambient medium is detected by chemoreceptors. It helps determine
flavor.
In humans, the sense of taste is
transduced by
gustatory hairs,
taste buds and is conveyed via three of the twelve
cranial nerves. The
facial nerve carries taste sensations from the anterior two thirds of the
tongue (excluding the circumvallate papillae, see
lingual papilla) and
soft palate, the
glossopharyngeal nerve carries taste sensations from the posterior one third of the tongue (including the circumvallate papillae) while a branch of the
vagus nerve carries some taste sensations from the back of the oral cavity (i.e.
pharynx and
epiglottis). Information from these cranial nerves is processed by the gustatory system. Impulses generated by the gustatory taste hairs on the superior surface of the tongue, travel from the tongue to either the facial or glossopharengeal cranial nerves. They move to the
medulla oblongata, to the the thalamus, ending up in the gustatorial area of the cortex of the
parietal lobe of the
cerebrum.
It is important to note that the
axons from these cranial nerves ascend in the
spinal cord without crossing over. These fibers terminate in the
amygdala,
hypothalamus, and ventral posterior medial nucleus of the
thalamus, which then projects to the
somatosensory cortex within the
brain. Thus, a
lesion of the
rostral nucleus solitarius, tractus solitarius, or solitariothalamic tract results in loss of taste from the ipsilesional, the same side as the lesion, half of the tongue.
As a general rule, taste is a holistic assessment of the interaction of the fundamental taste systems of
sweetness,
sourness,
bitterness,
saltiness, and savouriness, or "umami". Location of the stimulus on the tongue is not important, despite the common misperception of a "taste map" of sensitivity to different tastes thought to correspond to specific areas of the tongue [
1]. The "mouth map" is a myth, generally attributed to the mis-translation of a German text, and perpetuated in North American schools since the early twentieth century. In reality, the separate populations of taste buds, sensing each of the basic tastes, are distributed across the tongue, though not entirely equally; for instance, the front of the mouth is biased toward sweetness and the rear toward bitterness. The brain also plays a part in the tongue's sensory distribution. If, for instance, half of the tongue is blocked from sending information to the brain, rather than any diminishment, people will instead report that a doubling of psychological perception has occurred for each taste, and no loss to any one.
New evidence is emerging that supports the inclusion of a sixth taste category for free fatty acids, the chemical components of dietary fat. A taste receptor mechanism for free fatty acids has been identified [
2], an animal model for the detection of free fatty acids is being characterized [
3], and studies of human detection of free fatty acids are beginning[
4].
Many factors affect taste perception, including:
* Aging
* Hormonal influences
* Genetic variations - See
Phenylthiocarbamide* Oral temperature
* Drugs and chemicalsIt is also important to consider that
flavour is the overall, total sensation induced during
mastication (e.g. taste, touch, pain and smell). Smell (
olfactory stimulation) plays a major role in flavour perception.
*
ageusia (complete loss)
*
hypogeusia (partial loss)
*
parageusia (unpleasant taste)
*
dysgeusia (inaccurate taste)
Main article taste (aesthetics).
Taste can also refer to appreciation for
aesthetic quality, significantly applying the purely physical term to an intellectual quality. In such contexts
Taste begins to be used in a
metaphorical sense to refer to certain degrees of cultural competence, closely related to the concept of
discrimination; it can set distinctions between "tasteful" and "tasteless" or the embodiments of "good taste" or "bad taste", thus providing categories for
social division and reinforcing
cultural hierarchy.
The modern concept of "taste" is a product of the 16th century Italian
Mannerism: the idea of "taste" as a quality that is independent of the style that is simply its vehicle — though the style might be designated a taste, such as "the
Antique taste"— was born in the circle of
Pope Julius III and first realized at the
Villa Giulia he built on the edge of Rome in 1551â€"1555.
To the
Enlightenment, "taste" was still a universal character, which could be recognized by what pleased any cultured sensibility. With the shift in perspective that
Romanticism brought, it began to be thought that, to the contrary, "Beauty is in the eye of the beholder" and could be individually interpreted, with results that might be of equivalent aesthetic value.
To
taste'' is also used metaphorically to describe having a small amount of experience with something that gives a sense of its quality as a whole.
Livy is quoted to have said "they had not yet tasted the sweetness of freedom" while
Voltaire is quoted to have said "I tasted in her arms the delights of paradise". The word is often used as a noun in this sense, typically in such expressions as "I got a taste of it" or "It left a bad taste in my mouth."
*
Aesthetics*
Art*
Fine art*
Visual arts and design*
Connoisseur*
Critic *
Recommendation system (
computer science)
*
Supertaster
