Tactition is the sense of pressure perception. This definition is the one that differs the most from the Aristotelian model, as it specifically excludes the perception of pain and temperature (classified separately). Even within the limited field of "pressure" there is still disagreement as to how many distinct senses there actually are. In the skin, for example, there are different receptors responsible for the detection of light against heavy pressure, as well as brief against sustained pressure. Adding to the complexity is the fact that there are also distinct receptors that detect pressure in the visceral organs, such as that caused by a full stomach, and endocrinal receptors that cause the feeling of "tension", such as that associated with anxiety or excessive caffeine consumption. People who are blind or have low vision use a special white cane to feel obstacles, as well as the curbs when crossing a street, etc.; thus it "lengthens" one arm. See also Touch. Senses are the physiological methods of perception. ... PSYCHOLOGY In psychology and the cognitive sciences, perception is the process of acquiring, interpreting, selecting, and organizing sensory information. ... A definition delimits or describes the meaning of a concept or term by stating the essential properties of the entities or objects denoted by that concept or term. ... Aristotle (Ancient Greek: Aristotelēs 384 BC – March 7, 322 BC) was an ancient Greek philosopher, who studied with Plato and taught Alexander the Great. ... Pain is an unpleasant sensation which may be associated with actual or potential tissue damage and which may have physical and emotional components. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... Senses are the physiological methods of perception. ... Diagram of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system composed of a layer of tissues that protect underlying muscles and organs. ... In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. ... In anatomy, the viscera are the internal organs of an animal, in particular the internal organs of the head, thorax and abdomen. ... In biology, an organ (Latin: organum, instrument, tool) is a group of tissues, which perform a specific function or group of functions. ... The stomach (Gaster) In anatomy, the stomach (in ancient Greek στόμαχος) is an organ in the gastrointestinal tract used to digest food. ... The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organs. ... Flash point N/A RTECS number EV6475000 Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references Caffeine (sometimes called mateine when found in mate, and theine when found in tea) is a xanthine alkaloid found in the... Blindness can be defined physiologically as the condition of lacking visual perception. ... 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. ... A white cane is used by many people who are blind or visually impaired, both as a mobility tool and as a courtesy to others. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...