Senses are the physiological methods of perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, but most notably neuroscience, cognitive psychology (or cognitive science), and philosophy of perception. PSYCHOLOGY In psychology and the cognitive sciences, perception is the process of acquiring, interpreting, selecting, and organizing sensory information. ... Neuroscience is a field of study which deals with the structure, function, development, genetics, biochemistry, physiology, pharmacology and pathology of the nervous system, divided most generally into the central nervous system (the brain and spinal cord), and the peripheral nervous system, consisting of the myriad nerve pathways running throughout the... Cognitive psychology is the psychological science which studies cognition, the mental processes that are hypothesised to underlie behavior. ... Jump to: navigation, search Rendering of human brain based on MRI data Cognitive science is usually defined as the scientific study either of mind or of intelligence (e. ... Jump to: navigation, search The philosophy of perception concerns how mental processes and symbols depend on the world internal and external to the perceiver. ...

Definition of "sense"

There is no firm agreement amongst neurologists as to exactly how many senses there are, because of differing definitions of a sense. Although school children are still routinely taught that there are five senses (sight, hearing, touch, smell, taste; a classification first devised by Aristotle), it is generally agreed that there are at least nine different senses in humans, and a minimum of two more observed in other organisms. Jump to: navigation, search Aristotle, marble copy of bronze by Lysippos. ...

A broadly acceptable definition of a sense would be "a system that consists of a sensory cell type (or group of cell types) that respond to a specific kind of physical energy, and that correspond to a defined region (or group of regions) within the brain where the signals are received and interpreted". Where disputes arise is with regard to the exact classification of the various cell types and their mapping to regions of the brain.

List of Human senses

Using this definition several senses can be identified.

Based on this outline and depending on the chosen method of classification, somewhere between 9 and 21 human senses have been identified. Additionally, there are some other candidate physiological experiences which may or may not fall within the above classification (for example the sensory awareness of hunger and thirst).

Special senses

Sight or vision describes the ability to detect electromagnetic energy within the visible range (light) by the eye and the brain to interpret the image as "sight". There is disagreement whether or not this constitutes one, two or even three distinct senses. Neuroanatomists generally regard it as two senses, given that different receptors are responsible for the perception of colour (the frequency of photons of light) and brightness (amplitude/intensity - number of photons of light). Some argue that the perception of depth also constitutes a sense, but it is generally regarded that this is really a cognitive (that is, post-sensory) function of brain to interpret sensory input to derive new information. Jump to: navigation, search In medicine, Special senses is the term used to describe the senses of vision, hearing, taste, and smell. ... Jump to: navigation, search Visual perception is one of the senses, consisting of the ability to detect light and interpret (see) it as the perception known as sight or naked eye vision. ... Jump to: navigation, search Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific setting, electromagnetic radiation of any wavelength. ... Jump to: navigation, search This article needs to be cleaned up to conform to a higher standard of quality. ... Jump to: navigation, search Please help to figure out license type for the image Comparative brain sizes. For other articles about other subjects named brain see brain (disambiguation). ...

Hearing or audition is the sense of sound perception and results from tiny hair fibres in the inner ear detecting the motion of a membrane which vibrates in response to changes in the pressure exerted by atmospheric particles within (at best) a range of 9 to 20000 Hz, however this changes for each individual. Sound can also be detected as vibrations conducted through the body by tactition. Lower and higher frequencies than can be heard are detected this way only. Jump to: navigation, search Hearing, or audition, is one of the traditional five senses, and refers to the ability to detect sound. ... Jump to: navigation, search A schematic representation of hearing. ... Jump to: navigation, search An ear is an organ used by an animal to detect sound waves. ...

Taste or gustation is one of the two main "chemical" senses. It is well-known that there are at least four types of taste "bud" (receptor) on the tongue and hence, as should now be expected, there are anatomists who argue that these in fact constitute four or more different senses, given that each receptor conveys information to a slightly different region of the brain. Jump to: navigation, search Taste is one of the most common and fundamental of the senses of animals. ... Many animals have longer and more flexible tongues than humans. ...

The four well-known receptors detect sweet, salt, sour, and bitter, although the receptors for sweet and bitter have not been conclusively identified. A fifth receptor, for a sensation called "umami", was first theorised in 1908 and its existence confirmed in 2000 (see [1]). The umami receptor detects the amino acid glutamate, a flavor commonly found in meat, and in artificial flavourings such as monosodium glutamate. Human taste sensory organs, called taste buds or gustatory calyculi, and concentrated on the upper surface of the tongue, appear to be receptive to relatively few chemical species as tastes. ... Jump to: navigation, search In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ...

Smell or olfaction is the other "chemical" sense. Unlike taste, there are hundreds of olfactory receptors, each binding to a particular molecular feature, according to current theory. The combination of features of the odor molecule makes up what we perceive as the molecule's smell. 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. Jump to: navigation, search Olfaction, the sense of odor (smell), is the detection of chemicals dissolved in air (or, by animals that breathe water, in water). ... The olfactory system is the sensory system used for olfaction. ... An olfactory receptor neuron, also called an olfactory sensory neuron, is the primary transduction cell for olfaction in the olfactory system. ... Jump to: navigation, search VEASE FELIX RODRIGUEZ Image:Timnose. ...

If the different taste-senses are not regarded as separate senses one may argue that Taste and Smell should likewise be grouped together as one sense.

Somatic senses

Touch or tactition is the sense of pressure perception, generally in the skin. There are a variety of pressure receptors that respond to variations in pressure (firm, brushing, sustained, etc). Jump to: navigation, search In medicine, the colloquial term touch is usually replaced with somatic senses, to better reflect the variety of mechanisms involved. ... Touching is having or getting a zero distance; in geometry it refers especially to a tangent line or curve (cf. ... Jump to: navigation, search Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system; which is composed of a layer of tissues that protect underlying muscles and organs. ...

Thermoception is the sense of heat and the absence of heat (cold), also by the skin and including internal skin passages. There is some disagreement about how many senses this actually represents--the thermoceptors in the skin are quite different from the homeostatic thermoceptors which provide feedback on internal body temperature. Thermoception or thermoreception is the sense by which an organism perceives temperature. ... Jump to: navigation, search Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system; which is composed of a layer of tissues that protect underlying muscles and organs. ... Jump to: navigation, search Homeostasis or homoeostasis is the property of an open system, especially living organisms, to regulate its internal environment so as to maintain a stable condition, by means of multiple dynamic equilibrium adjustments controlled by interrelated regulation mechanisms. ...

Nociception is the perception of pain. It can be classified as from one to three senses, depending on the classification method. The three types of pain receptors are cutaneous (skin), somatic (joints and bones) and visceral (body organs). For a considerable time it was believed that pain was simply the overloading of pressure receptors, but research in the first half of the 20th century indicated that pain was a distinct phenomenon that intertwined with all other senses, including touch. Pain is both a sensory and emotional experience, generally associated tissue damage, or inflammation. ...

Other

Equilibrioception is the perception of balance and is related to cavities containing fluid in the inner ear. There is some disagreement whether or not this also includes the sense of "direction" or orientation. However, as with depth perception earlier, it is generally regarded that "direction" is a post-sensory cognitive awareness. Equilibrioception or sense of balance is one of the physiological senses. ...

Proprioception is the perception of body awareness and is a sense that people rely on enormously, yet are frequently not aware of. More easily demonstrated than explained, proprioception is the "unconscious" awareness of where the various regions of the body are located at any one time. (This can be demonstrated by anyone closing their eyes and waving their hand around. 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 (from Latin proprius, meaning ones own and perception) is the sense of the position of parts of the body, relative to other neighbouring parts of the body. ...

Non-human senses

All animals have receptors to sense the world around them, including many of the senses listed above for humans. However, the mechanisms and capabilities vary widely. Dogs have a much keener sense of smell than humans, although the mechanism is similar. Pit vipers 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. This is, however, also just sight extended to include more frequencies. Insects have olfactory receptors on their antennae. Ctenophores have a balance receptor (a statocyst) that works very differently from the mammalian semi-circular canals. In addition, some animals have senses that humans do not, including the following: Jump to: navigation, search Trinomial name Canis lupus familiaris (Linnaeus, 1758) The dog is a canine mammal of the Order Carnivora that has been domesticated for at least 14,000 years and perhaps for as long as 150,000 years based on recent evidence. ... Genera See text. ... Jump to: navigation, search BoA (born November 5, 1986 in Guri, Korea) is a South Korean pop singer. ... Jump to: navigation, search Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... Jump to: navigation, search Classes & Orders Subclass: Apterygota Orders Archaeognatha (Bristletails) Thysanura (Silverfish) Monura - extinct Subclass: Pterygota Orders Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Infraclass: Neoptera Orders Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, etc) Phasmatodea (walking... Antennae (singular antenna), are the paired appendages connecting to the first (and in crustaceans also to the second) segment of the head of the members of all subphyla of the arthropods except Chelicerata. ... Classes Tentaculata Nuda Ctenophores are jellyfish-like animals commonly called comb jellies, sea gooseberries, sea walnuts, or Venus girdles. ... The statocyst is a balance organ present in some aquatic invertebrates (Cnidarians, Ctenophores, Bilaterians). ...

Electroception (or "electroreception"), the most significant of the non-human senses, is the ability to detect electric fields. Several species of fish, sharks and rays have evolved the capacity to sense changes in electric fields in their immediate vicinity. 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 generating and sensing capacities for social communication. The mechanisms by which electroceptive fishes construct a spatial representation from very small differences in field potentials involve comparisons of spike latencies from different parts of the fish's body. Electroreception, sometimes written as electroception, is the biological ability to receive and make use of electrical impulses. ... Jump to: navigation, search In physics, an electric field or E-field is an effect produced by an electric charge that exerts a force on charged objects in its vicinity. ... Jump to: navigation, search Orders Hexanchiformes Squaliformes Pristiophoriformes Squatiniformes Heterodontiformes Orectolobiformes Carcharhiniformes Lamniformes Sharks are a group (superorder Selachimorpha) of fish, with a full cartilaginous skeleton, a streamlined body plan, with normally 5, but up to 7 (depending on species) gill slits along the side of, or beginning slightly behind...

The only order of mammals which is known to demonstrate electroception is the monotreme order. Among these mammals, the platypus (see [2]) has the most acute sense of electroception. Jump to: navigation, search Families Kollikodontidae (extinct) Ornithorhynchidae - Platypus Tachyglossidae - Echidnas Steropodontidae (extinct) Monotremes (< monos, single + trema, hole; refers to the cloaca) are mammals that are best known for laying eggs, instead of giving birth to live young like marsupials (Metatheria) and placental mammals (Eutheria). ... Jump to: navigation, search This article is about the mammal. ...

Humans (and probably other mammals) can detect electric fields 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 however not Electroception since there is no separate sense for it. The presence of an electrical field is merely concluded from a side-effect of another sense.

Magnetoception (or "magnetoreception") is the ability to detect fluctuations in magnetic fields and is most commonly observed in birds, though it has also been observed in insects such as bees. Although there is no dispute that this sense exists in many avians (it is essential to the navigational abilities of migratory birds) it is not a well understood phenomenon (see [3]). Magnetoception (or magnetoreception) is the ability to detect fluctuations in magnetic fields and is most commonly observed in birds, though it has also been observed in many other migrational animals. ... Jump to: navigation, search Current flowing through a wire produces a magnetic field (M) around the wire. ... Jump to: navigation, search Orders Many - see section below. ... Jump to: navigation, search Families Andrenidae Apidae Colletidae Halictidae Heterogynaidae Megachilidae Melittidae Oxaeidae Sphecidae Stenotritidae Bees (Apoidea superfamily) are flying insects, closely related to wasps and ants. ... For other meanings of bird, see bird (disambiguation). ...

Magnetotactic bacteria build miniature magnets inside themselves and use them to determine their orientation relative to the Earth's magnetic field.

Echolocation is the ability to determine orientation to other objects through interpretation of reflected sound (like sonar). Bats and dolphins are noted for this ability, though some other mammals and birds do as well. It is most often used to navigate through poor lighting conditions or to identify and track prey. There is presently an uncertainty whether this is simply an extremely developed post-sensory interpretation of auditory perceptions, or actually constitutes a separate sense. Resolution of the issue will require brain scans of animals while they actually perform echolocation, a task which has proved difficult in practice. This article is in need of attention from an expert on the subject. ... Jump to: navigation, search The F70 type frigates (here, La Motte-Picquet) are fitted with VDS (Variable Depth Sonar) type DUBV43 or DUBV43C tugged sonars Sonar (sound navigation and ranging) is a technique that uses sound propagation under water to navigate or to detect other watercraft. ... Jump to: navigation, search Families Antrozoidae Craseonycteridae Emballonuridae Furipteridae Megadermatidae Molossidae Mormoopidae Mystacinidae Myzopodidae Natalidae Noctilionidae Nycteridae Phyllostomidae Pteropodidae Rhinolophidae Rhinopomatidae Thyropteridae Vespertilionidae Bats are flying mammals in order Chiroptera with forelimbs developed as wings. ... Jump to: navigation, search Genera See article below. ...

Pressure detection uses the lateral line, which is a pressure-sensing system of hairs found in fish and some aquatic amphibians. It is used primary for navigation, hunting, and schooling. In fish, the lateral line is a sense organ used to detect movement in the surrounding water. ... For other uses, see Amphibian (disambiguation). ...

See also

• Attention
• Auditory illusion, Optical illusion, Touch illusion
• Empiricism
• Sensation
• Multimodal integration
• Sensitivity (human)
• Sense of time
• Human sensory system
• Sensorium

Look up Attention on Wiktionary, the free dictionary Attention is the cognitive process of selectively concentrating on one thing while ignoring other things. ... An auditory illusion is an illusion of hearing (sense), the sound equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or impossible sounds. ... Jump to: navigation, search An optical illusion is a type of illusion characterized by visually perceived images that are deceptive or misleading [1]. Information gathered by the eye is interpreted by the brain to give the perception that something is present when it is not. ... Touch illusions are illusions that exploit the sense of touch. ... Jump to: navigation, search Empiricism (greek εμπειρισμός, from empirical, latin experientia - the experience), is the philosophical doctrine that all human knowledge ultimately comes from the senses and from experience. ... Jump to: navigation, search In psychology, sensation is the first stage in the chain of biochemical and neurologic events that begins with the impinging of a stimulus upon the receptor cells of a sensory organ, which then leads to perception, the mental state that is reflected in statements like I... Multimodal integration, also known as multisensory integration, is the integration in the brain of inputs from the various senses, to form multimodal representations or percepts. ... The sensitivity of a human, often considered with regard to a particular kind of stimulus, is the strength of the feeling it results in, in comparison with the strength of the stimulus. ... Jump to: navigation, search Although sense of time is not associated with specific sensory system, the work of psychologists and neuroscientists indicates that our brains do have a system governing perception of time. ... (See also sense) A sensory system is a part of the nervous system that consists of sensory receptors, neural pathways, and those parts of the brain responsible for processing the information. ... The term sensorium (plural: sensoria) refers to the sum of an organisms perception, the seat of sensation where it experiences and interprets the environments within which it lives. ...

External links

• The physiological and psychological underpinnings of senses
• The Physiology of the Senses tutorial 12 animated chapters on vision, hearing, touch, balance and memory.

• The 2004 Nobel Prize in Physiology or Medicine (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.