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= Sense =
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Introduction
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A sense is a physiological capacity of organisms that provides data
for perception. The senses and their operation, classification, and
theory are overlapping topics studied by a variety of fields, most
notably neuroscience, cognitive psychology (or cognitive science), and
philosophy of perception. The nervous system has a specific sensory
nervous system, and a sense organ, or sensor, dedicated to each sense.
Humans have a multitude of sensors. Sight (vision, visual sense),
hearing (audition, auditory sense), taste (gustation, gustatory
sense), smell (olfaction, olfactory sense), and touch
(somatosensation, somatosensory sense) are the five traditionally
recognized senses. The ability to detect other stimuli beyond those
governed by these most broadly recognized senses also exists, and
these sensory modalities include temperature (thermoception),
kinesthetic sense (proprioception), pain (nociception), balance
(equilibrioception), vibration (mechanoreception), and various
internal stimuli (e.g. the different chemoreceptors for detecting salt
and carbon dioxide concentrations in the blood, or sense of hunger and
sense of thirst). However, what constitutes a sense is a matter of
some debate, leading to difficulties in defining what exactly a
distinct sense is, and where the borders lie between responses to
related stimuli.
Other animals also have receptors to sense the world around them, with
degrees of capability varying greatly between species. Humans have a
comparatively weak sense of smell and a stronger sense of sight
relative to many other mammals while some animals may lack one or more
of the traditional five senses. Some animals may also intake and
interpret sensory stimuli in very different ways. Some species of
animals are able to sense the world in a way that humans cannot, with
some species able to sense electrical and magnetic fields, and detect
water pressure and currents.
Definition
======================================================================
A broadly acceptable definition of a sense would be "A system that
consists of a group of sensory cell types that responds to a specific
physical phenomenon, and that corresponds to a particular group of
regions within the brain where the signals are received and
interpreted." There is no firm agreement as to the number of senses
because of differing definitions of what constitutes a sense.
The senses are frequently divided into exteroceptive and
interoceptive:
* 'Exteroceptive senses' are senses that perceive the body's own
position, motion, and state, known as 'proprioceptive senses'.
External senses include the traditional five: sight, hearing, touch,
smell and taste, as well as thermoception (temperature differences)
and possibly an additional weak magnetoception (direction).
Proprioceptive senses include nociception (pain); equilibrioception
(balance); proprioception (a sense of the position and movement of the
parts of one's own body).
* 'Interoceptive senses' are senses that perceive sensations in
internal organs.
Non-human animals may possess senses that are absent in humans, such
as electroreception and detection of polarized light.
In Buddhist philosophy, Ayatana or "sense-base" includes the mind as a
sense organ, in addition to the traditional five. This addition to the
commonly acknowledged senses may arise from the psychological
orientation involved in Buddhist thought and practice. The mind
considered by itself is seen as the principal gateway to a different
spectrum of phenomena that differ from the physical sense data. This
way of viewing the human sense system indicates the importance of
internal sources of sensation and perception that complements our
experience of the external world.
Sight
=======
Sight or vision (adjectival form: visual/optical) is the capability of
the eye(s) to focus and detect images of visible light on
photoreceptors in the retina of each eye that generates electrical
nerve impulses for varying colors, hues, and brightness. There are
two types of photoreceptors: rods and cones. Rods are very sensitive
to light but do not distinguish colors. Cones distinguish colors but
are less sensitive to dim light. There is some disagreement as to
whether this constitutes one, two or three senses. Neuroanatomists
generally regard it as two senses, given that different receptors are
responsible for the perception of color and brightness. Some argue
that stereopsis, the perception of depth using both eyes, also
constitutes a sense, but it is generally regarded as a cognitive (that
is, post-sensory) function of the visual cortex of the brain where
patterns and objects in images are recognized and interpreted based on
previously learned information. This is called visual memory.
The inability to see is called blindness. Blindness may result from
damage to the eyeball, especially to the retina, damage to the optic
nerve that connects each eye to the brain, and/or from stroke
(infarcts in the brain). Temporary or permanent blindness can be
caused by poisons or medications.
People who are blind from degradation or damage to the visual cortex,
but still have functional eyes, are actually capable of some level of
vision and reaction to visual stimuli but not a conscious perception;
this is known as blindsight. People with blindsight are usually not
aware that they are reacting to visual sources, and instead just
unconsciously adapt their behavior to the stimulus.
On February 14, 2013 researchers developed a neural implant that gives
rats the ability to sense infrared light which for the first time
provides living creatures with new abilities, instead of simply
replacing or augmenting existing abilities.
Hearing
=========
Hearing or audition (adjectival form: auditory) is the sense of sound
perception. Hearing is all about vibration. Mechanoreceptors turn
motion into electrical nerve pulses, which are located in the inner
ear. Since sound is vibration, propagating through a medium such as
air, the detection of these vibrations, that is the sense of the
hearing, is a mechanical sense because these vibrations are
mechanically conducted from the eardrum through a series of tiny bones
to hair-like fibers in the inner ear, which detect mechanical motion
of the fibers within a range of about 20 to 20,000 hertz, with
substantial variation between individuals. Hearing at high frequencies
declines with an increase in age. Inability to hear is called deafness
or hearing impairment. Sound can also be detected as vibrations
conducted through the body by tactition. Lower frequencies that can be
heard are detected this way. Some deaf people are able to determine
the direction and location of vibrations picked up through the feet.
Taste
=======
Taste or gustation (adjectival form: gustatory) is one of the
traditional five senses. It refers to the capability to detect the
taste of substances such as food, certain minerals, and poisons, etc.
The sense of taste is often confused with the "sense" of flavor, which
is a combination of taste and smell perception. Philippe Mercier - The
Sense of Taste - Google Art Project Flavor depends on odor, texture,
and temperature as well as on taste. Humans receive tastes through
sensory organs called taste buds, or gustatory calyculi, concentrated
on the upper surface of the tongue. There are five basic tastes:
sweet, bitter, sour, salty and umami. Other tastes such as calcium and
free fatty acids may also be basic tastes but have yet to receive
widespread acceptance. The inability to taste is called ageusia.
Flies and butterflies have taste organs on their feet, allowing them
to taste anything they land on. Catfish have taste organs across their
entire bodies, and can taste anything they touch, including chemicals
in the water.
Smell
=======
Smell or olfaction (adjectival form: olfactory) is the other
"chemical" sense. Unlike taste, there are hundreds of olfactory
receptors (388 according to one source), each binding to a particular
molecular feature. Odor molecules possess a variety of features and,
thus, excite specific receptors more or less strongly. This
combination of excitatory signals from different receptors makes up
what we perceive as the molecule's smell. The sense of smell Bequest
of [[Mrs E.G. Elgar, 1945 Museum of New Zealand Te Papa Tongarewa.]]
In the brain, olfaction is processed by the olfactory system.
Olfactory receptor neurons in the nose differ from most other neurons
in that they die and regenerate on a regular basis. The inability to
smell is called anosmia. Some neurons in the nose are specialized to
detect pheromones.
An example of smell in non-mammals is that of sharks, which combine
their keen sense of smell with timing to determine the direction of a
smell. They follow the nostril that first detected the smell. Insects
have olfactory receptors on their antennae. Although it is unknown to
the degree and magnitude which non-human animals can smell better than
humans.
Touch
=======
Touch or somatosensation (adjectival form: somatic), also called
tactition (adjectival form: tactile) or mechanoreception, is a
perception resulting from activation of neural receptors, generally in
the skin including hair follicles, but also in the tongue, throat, and
mucosa. A variety of pressure receptors respond to variations in
pressure (firm, brushing, sustained, etc.). The touch sense of itching
caused by insect bites or allergies involves special itch-specific
neurons in the skin and spinal cord. The loss or impairment of the
ability to feel anything touched is called tactile anesthesia.
Paresthesia is a sensation of tingling, pricking, or numbness of the
skin that may result from nerve damage and may be permanent or
temporary.
Balance and acceleration
==========================
Balance, equilibrioception, or vestibular sense is the sense that
allows an organism to sense body movement, direction, and
acceleration, and to attain and maintain postural equilibrium and
balance. The organ of equilibrioception is the vestibular labyrinthine
system found in both of the inner ears. In technical terms, this organ
is responsible for two senses of angular momentum acceleration and
linear acceleration (which also senses gravity), but they are known
together as equilibrioception.
The vestibular nerve conducts information from sensory receptors in
three ampulla that sense motion of fluid in three semicircular canals
caused by three-dimensional rotation of the head. The vestibular
nerve also conducts information from the utricle and the saccule,
which contain hair-like sensory receptors that bend under the weight
of otoliths (which are small crystals of calcium carbonate) that
provide the inertia needed to detect head rotation, linear
acceleration, and the direction of gravitational force.
Temperature
=============
Thermoception is the sense of heat and the absence of heat (cold) by
the skin and internal skin passages, or, rather, the heat flux (the
rate of heat flow) in these areas. There are specialized receptors for
cold (declining temperature) and for heat (increasing temperature).
The cold receptors play an important part in the animal's sense of
smell, telling wind direction. The heat receptors are sensitive to
infrared radiation and can occur in specialized organs, for instance
in pit vipers. The thermoceptors in the skin are quite different from
the homeostatic thermoceptors in the brain (hypothalamus), which
provide feedback on internal body temperature.
Proprioception
================
Proprioception, the kinesthetic sense, provides the parietal cortex of
the brain with information on the movement and relative positions of
the parts of the body. Neurologists test this sense by telling
patients to close their eyes and touch their own nose with the tip of
a finger. Assuming proper proprioceptive function, at no time will the
person lose awareness of where the hand actually is, even though it is
not being detected by any of the other senses. Proprioception and
touch are related in subtle ways, and their impairment results in
surprising and deep deficits in perception and action.
Pain
======
Nociception (physiological pain) signals nerve-damage or damage to
tissue. The three types of pain receptors are cutaneous (skin),
somatic (joints and bones), and visceral (body organs). It was
previously believed that pain was simply the overloading of pressure
receptors, but research in the first half of the 20th century
indicated that pain is a distinct phenomenon that intertwines with all
of the other senses, including touch. Pain was once considered an
entirely subjective experience, but recent studies show that pain is
registered in the anterior cingulate gyrus of the brain. The main
function of pain is to attract our attention to dangers and motivate
us to avoid them. For example, humans avoid touching a sharp needle,
or hot object, or extending an arm beyond a safe limit because it is
dangerous, and thus hurts. Without pain, people could do many
dangerous things without being aware of the dangers.
Magnetoception
================
Magnetoception (or magnetoreception) is the ability to detect the
direction one is facing based on the Earth's magnetic field.
Directional awareness is most commonly observed in birds, which rely
on their magnetic sense to navigate during migration. It has also been
observed in insects such as bees. Cattle make use of magnetoception to
align themselves in a north-south direction. Magnetotactic bacteria
build miniature magnets inside themselves and use them to determine
their orientation relative to the Earth's magnetic field. There has
been some recent (tentative) research suggesting that the Rhodopsin in
the human eye, which responds particularly well to blue light, can
facilitate magnetoception in humans.
Sexual stimulation
====================
Sexual stimulation is any stimulus (including bodily contact) that
leads to, enhances and maintains sexual arousal, and may lead to
orgasm. Distinct from the general sense of touch, sexual stimulation
is strongly tied to hormonal activity and chemical triggers in the
body. Although sexual arousal may arise without physical stimulation,
achieving orgasm usually requires physical sexual stimulation
(stimulation of the Krause-Finger corpuscles found in erogenous zones
of the body).
Other internal senses{{anchor|Interoception}}
===============================================
An internal sense also known as interoception is "any sense that is
normally stimulated from within the body". These involve numerous
sensory receptors in internal organs. Interoception is thought to be
atypical in clinical conditions such as alexithymia.
Some examples of specific receptors are:
* Hunger is a sensation that is governed by a set of brain structures
(e.g., the hypothalamus) that are responsible for energy homeostasis.
* Pulmonary stretch receptors are found in the lungs and control the
respiratory rate.
* Peripheral chemoreceptors in the brain monitor the carbon dioxide
and oxygen levels in the brain to give a feeling of suffocation if
carbon dioxide levels get too high.
* The chemoreceptor trigger zone is an area of the medulla in the
brain that receives inputs from blood-borne drugs or hormones, and
communicates with the vomiting center.
* Chemoreceptors in the circulatory system also measure salt levels
and prompt thirst if they get too high; they can also respond to high
blood sugar levels in diabetics.
* Cutaneous receptors in the skin not only respond to touch, pressure,
temperature and vibration, but also respond to vasodilation in the
skin such as blushing.
* Stretch receptors in the gastrointestinal tract sense gas distension
that may result in colic pain.
* Stimulation of sensory receptors in the esophagus result in
sensations felt in the throat when swallowing, vomiting, or during
acid reflux.
* Sensory receptors in pharynx mucosa, similar to touch receptors in
the skin, sense foreign objects such as mucous and food that may
result in a gag reflex and corresponding gagging sensation.
* Stimulation of sensory receptors in the urinary bladder and rectum
may result in sensations of fullness.
* Stimulation of stretch sensors that sense dilation of various blood
vessels may result in pain, for example headache caused by
vasodilation of brain arteries.
* Cardioception refers to the perception of the activity of the heart.
* Opsins and direct DNA damage in melanocytes and keratinocytes can
sense ultraviolet radiation, which plays a role in pigmentation and
sunburn.
*Baroreceptors relay blood pressure information to the brain and
maintain proper homeostatic blood pressure.
Time
======
Chronoception refers to how the passage of time is perceived and
experienced. Although the sense of time is not associated with a
specific sensory system, the work of psychologists and neuroscientists
indicates that human brains do have a system governing the perception
of time, composed of a highly distributed system involving the
cerebral cortex, cerebellum and basal ganglia. One particular
component, the suprachiasmatic nucleus, is responsible for the
circadian (or daily) rhythm, while other cell clusters appear to be
capable of shorter-range (ultradian) timekeeping.
One or more dopaminergic pathways in the central nervous system appear
to have a strong modulatory influence on mental chronometry,
particularly interval timing.
Agency
========
The sense of agency refers to the subjective feeling of having chosen
a particular action. Some conditions, such as schizophrenia, can lead
to a loss of this sense, causing a person to feel like a machine or
even leading to delusions of being controlled from some outside
source. The opposite extreme occurs too, with some people experiencing
everything in their environment as if they had decided that it would
happen.
Even in non-pathological cases, there is a measurable difference
between making a decision and the feeling of agency. Through methods
such as the Libet experiment, a gap of half a second or more can be
detected from the time when there are detectable neurological signs of
a decision having been made to the time when the subject actually
becomes conscious of the decision.
There are also experiments in which an illusion of agency is induced
in psychologically normal subjects. In Wegner and Wheatley 1999,
subjects were given instructions to move a mouse around a scene and
point to an image about once every thirty seconds. However, a second
person�acting as a test subject but actually a confederate�had their
hand on the mouse at the same time, and controlled some of the
movement. Experimenters were able to arrange for subjects to perceive
certain "forced stops" as if they were their own choice.
Familiarity
=============
Recognition memory is sometimes divided into two functions by
neuroscientists: familiarity and recollection. A strong sense of
familiarity can occur without any recollection, for example in cases
of deja vu. The temporal lobe, in particular the perirhinal cortex,
responds differently to stimuli which feel novel than to things which
feel familiar. Firing rates in the perirhinal cortex are connected
with the sense of familiarity in humans and other mammals. In tests,
stimulating this area at 10-15 Hz caused animals to treat even novel
images as familiar, and stimulation at 30-40 Hz caused novel images to
be partially treated as familiar. Specifically, stimulation at 30-40
Hz led to animals looking at a familiar image for longer periods, as
they would for an unfamiliar one; but it did not lead to the same
exploration behavior normally associated with novelty. Recent studies
on lesions in the area concluded that rats with a damaged perirhinal
cortex were still more interested in exploring when novel objects were
present, but seemed unable to tell novel objects from familiar
ones�they examined both equally. Thus, other brain regions are
involved with noticing unfamiliarity, but the perirhinal cortex is
needed to associate the feeling with a specific source.
Analogous to human senses
===========================
Other living organisms have receptors to sense the world around them,
including many of the senses listed above for humans. However, the
mechanisms and capabilities vary widely.
Vomeronasal organ
===================
Many animals (salamanders, reptiles, mammals) have a vomeronasal organ
that is connected with the mouth cavity. In mammals it is mainly used
to detect pheromones of marked territory, trails, and sexual state.
Reptiles like snakes and monitor lizards make extensive use of it as a
smelling organ by transferring scent molecules to the vomeronasal
organ with the tips of the forked tongue. In reptiles the vomeronasal
organ is commonly referred to as Jacobsons organ. In mammals, it is
often associated with a special behavior called flehmen characterized
by uplifting of the lips. The organ is vestigial in humans, because
associated neurons have not been found that give any sensory input in
humans.
Vision and light sensing
==========================
Cats have the ability to see in low light, which is due to muscles
surrounding their irides-which contract and expand their pupils-as
well as to the tapetum lucidum, a reflective membrane that optimizes
the image.
Pit vipers, pythons and some boas have organs that allow them to
detect infrared light, such that these snakes are able to sense the
body heat of their prey. The common vampire bat may also have an
infrared sensor on its nose. It has been found that birds and some
other animals are tetrachromats and have the ability to see in the
ultraviolet down to 300 nanometers. Bees and dragonflies are also able
to see in the ultraviolet. Mantis shrimps can perceive both polarized
light and multispectral images and have twelve distinct kinds of color
receptors, unlike humans which have three kinds and most mammals which
have two kinds.
Cephalopods have the ability to change color using chromatophores in
their skin. Researchers believe that opsins in the skin can sense
different wavelengths of light and help the creatures choose a
coloration that camouflages them, in addition to light input from the
eyes. Other researchers hypothesize that cephalopod eyes in species
which only have a single photoreceptor protein may use chromatic
aberration to turn monochromatic vision into color vision, explaining
pupils shaped like the letter U, the letter W, or a dumbbell, as well
as explaining the need for colorful mating displays. Some cephalopods
can distinguish the polarization of light.
Balance
=========
Many invertebrates have a statocyst, which is a sensor for
acceleration and orientation that works very differently from the
mammalian's semi-circular canals.
Sensing gravity
=================
Some plants (such as mustard) have genes that are necessary for the
plant to sense the direction of gravity. If these genes are disabled
by a mutation, a plant cannot grow upright.
Not analogous to human senses
===============================
In addition, some animals have senses that humans do not, including
the following:
Echolocation
==============
Certain animals, including bats and cetaceans, have the ability to
determine orientation to other objects through interpretation of
reflected sound (like sonar). They most often use this to navigate
through poor lighting conditions or to identify and track prey. There
is currently an uncertainty whether this is simply an extremely
developed post-sensory interpretation of auditory perceptions or it
actually constitutes a separate sense. Resolution of the issue will
require brain scans of animals while they actually perform
echolocation, a task that has proven difficult in practice.
Blind people report they are able to navigate and in some cases
identify an object by interpreting reflected sounds (especially their
own footsteps), a phenomenon known as human echolocation.
Electroreception
==================
Electroreception (or electroception) is the ability to detect electric
fields. Several species of fish, sharks, and rays have the capacity to
sense changes in electric fields in their immediate vicinity. For
cartilaginous fish this occurs through a specialized organ called the
Ampullae of Lorenzini. Some fish passively sense changing nearby
electric fields; some generate their own weak electric fields, and
sense the pattern of field potentials over their body surface; and
some use these electric field generating and sensing capacities for
social communication. The mechanisms by which electroceptive fish
construct a spatial representation from very small differences in
field potentials involve comparisons of spike latencies from different
parts of the fish's body.
The only orders of mammals that are known to demonstrate
electroception are the dolphin and monotreme orders. Among these
mammals, the platypus has the most acute sense of electroception.
A dolphin can detect electric fields in water using electroreceptors
in vibrissal crypts arrayed in pairs on its snout and which evolved
from whisker motion sensors. These electroreceptors can detect
electric fields as weak as 4.6 microvolts per centimeter, such as
those generated by contracting muscles and pumping gills of potential
prey. This permits the dolphin to locate prey from the seafloor where
sediment limits visibility and echolocation.
Spiders have been shown to detect electric fields to determine a
suitable time to extend web for 'ballooning'.
Body modification enthusiasts have experimented with magnetic implants
to attempt to replicate this sense. However, in general humans (and it
is presumed other mammals) can detect electric fields only indirectly
by detecting the effect they have on hairs. An electrically charged
balloon, for instance, will exert a force on human arm hairs, which
can be felt through tactition and identified as coming from a static
charge (and not from wind or the like). This is not electroreception,
as it is a post-sensory cognitive action.
Hygroreception
================
Hygroreception is the ability to detect changes in the moisture
content of the environment.
Infrared sensing
==================
The ability to sense infrared thermal radiation evolved independently
in various families of snakes. Essentially, it allows these reptiles
to "see" radiant heat at wavelengths between 5 and 30 μm to a degree
of accuracy such that a blind rattlesnake can target vulnerable body
parts of the prey at which it strikes. It was previously thought that
the organs evolved primarily as prey detectors, but it is now believed
that it may also be used in thermoregulatory decision making. The
facial pit underwent parallel evolution in pitvipers and some boas and
pythons, having evolved once in pitvipers and multiple times in boas
and pythons. The electrophysiology of the structure is similar between
the two lineages, but they differ in gross structural anatomy. Most
superficially, pitvipers possess one large pit organ on either side of
the head, between the eye and the nostril (Loreal pit), while boas and
pythons have three or more comparatively smaller pits lining the upper
and sometimes the lower lip, in or between the scales. Those of the
pitvipers are the more advanced, having a suspended sensory membrane
as opposed to a simple pit structure. Within the family Viperidae, the
pit organ is seen only in the subfamily Crotalinae: the pitvipers. The
organ is used extensively to detect and target endothermic prey such
as rodents and birds, and it was previously assumed that the organ
evolved specifically for that purpose. However, recent evidence shows
that the pit organ may also be used for thermoregulation. According to
Krochmal et al., pitvipers can use their pits for thermoregulatory
decision making while true vipers (vipers who do not contain
heat-sensing pits) cannot.
In spite of its detection of IR light, the pits' IR detection
mechanism is not similar to photoreceptors - while photoreceptors
detect light via photochemical reactions, the protein in the pits of
snakes is in fact a temperature sensitive ion channel. It senses
infrared signals through a mechanism involving warming of the pit
organ, rather than chemical reaction to light. This is consistent with
the thin pit membrane, which allows incoming IR radiation to quickly
and precisely warm a given ion channel and trigger a nerve impulse, as
well as vascularize the pit membrane in order to rapidly cool the ion
channel back to its original "resting" or "inactive" temperature.
Other
=======
*Pressure detection uses the organ of Weber, a system consisting of
three appendages of vertebrae transferring changes in shape of the gas
bladder to the middle ear. It can be used to regulate the buoyancy of
the fish. Fish like the weather fish and other loaches are also known
to respond to low pressure areas but they lack a swim bladder.
* Current detection is a detection system of water currents,
consisting mostly of vortices, found in the lateral line of fish and
aquatic forms of amphibians. The lateral line is also sensitive to
low-frequency vibrations. The mechanoreceptors are hair cells, the
same mechanoreceptors for vestibular sense and hearing. It is used
primarily for navigation, hunting, and schooling. The receptors of the
electrical sense are modified hair cells of the lateral line system.
*Polarized light direction/detection is used by bees to orient
themselves, especially on cloudy days. Cuttlefish, some beetles, and
mantis shrimp can also perceive the polarization of light. Most
sighted humans can in fact learn to roughly detect large areas of
polarization by an effect called Haidinger's brush, however this is
considered an entoptic phenomenon rather than a separate sense.
* Slit sensillae of spiders detect mechanical strain in the
exoskeleton, providing information on force and vibrations.
Plant senses
==============
By using a variety of sense receptors, plants sense light, gravity,
temperature, humidity, chemical substances, chemical gradients,
reorientation, magnetic fields, infections, tissue damage and
mechanical pressure. The absence of a nervous system notwithstanding,
plants interpret and respond to these stimuli by a variety of hormonal
and cell-to-cell communication pathways that result in movement,
morphological changes and physiological state alterations at the
organism level, that is, result in plant behavior. Such physiological
and cognitive functions are generally not believed to give rise to
mental phenomena or qualia, however, as these are typically considered
the product of nervous system activity. The emergence of mental
phenomena from the activity of systems functionally or
computationally analogous to that of nervous systems is, however, a
hypothetical possibility explored by some schools of thought in the
philosophy of mind field, such as functionalism and computationalism.
Culture
======================================================================
In the time of William Shakespeare, there were commonly reckoned to be
five wits or five senses. At that time, the words "sense" and "wit"
were synonyms, so the senses were known as the five outward wits. This
traditional concept of five senses is common today.
The traditional five senses are enumerated as the "five material
faculties" (') in Hindu literature. They appear in allegorical
representation as early as in the Katha Upanishad (roughly 6th century
BC), as five horses drawing the "chariot" of the body, guided by the
mind as "chariot driver".
Depictions of the five traditional senses as allegory became a popular
subject for seventeenth-century artists, especially among Dutch and
Flemish Baroque painters. A typical example is Gérard de Lairesse's
'Allegory of the Five Senses' (1668), in which each of the figures in
the main group alludes to a sense: Sight is the reclining boy with a
convex mirror, hearing is the cupid-like boy with a triangle, smell is
represented by the girl with flowers, taste is represented by the
woman with the fruit, and touch is represented by the woman holding
the bird.
See also
======================================================================
* Aesthesis
* Apperception
* Attention
* �yatana (sense bases in Theravada Buddhism)
* Chemesthesis
* Empiricism
* Extrasensory Perception
* Entoptic phenomenon
* Increased sensitivity:
** Supertaster
** Hyperesthesia
** Hyperacusis
* Illusions
** Auditory illusion
** Optical illusion
** Touch illusion
* Intuition
* Multisensory integration
* Phantom limb
* Remote sensing
* Saḷ�yatana and Ayatana (the six senses as a concept in Buddhism)
* Sensation and perception psychology
* Sense of direction
* Sensitivity (human)
* Sensorium
* Sensory processing disorder
* Sensus divinitatis
* Synesthesia (Ideasthesia)
External links
======================================================================
* The 2004 Nobel Prize in Physiology or Medicine
([
http://nobelprize.org/medicine/laureates/2004/index.html announced]
4 October 2004) was won by Richard Axel and Linda Buck for their work
explaining olfaction, published first in a joint paper in 1991 that
described the very large family of about one thousand genes for
odorant receptors and how the receptors link to the brain.
* [
https://www.scribd.com/doc/32909/Sensing-or-feeling/ Answers to
several questions related to senses and human feeling from curious
kids]
*[
https://web.archive.org/web/20070520084243/http://www.physpharm.fmd.uwo.ca/und
ergrad/sensesweb/
The Physiology of the Senses tutorial] 12 animated chapters on vision,
hearing, touch, balance and memory.
License
=========
All content on Gopherpedia comes from Wikipedia, and is licensed under CC-BY-SA
License URL:
http://creativecommons.org/licenses/by-sa/3.0/
Original Article:
http://en.wikipedia.org/wiki/Sense
