Animation of the fusiform area, the area damaged in prosopagnosia. Prosopagnosia, also called face blindness, is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one’s own face (self-recognition), is impaired, while other aspects of visual processing (e.g., object discrimination) and intellectual functioning (e.g., decision making) remain intact.
The Visual Cycle. hν = Incident Photon Visual phototransduction is the sensory transduction of the visual system. It is a process by which light is converted into electrical signals in the rod cells, cone cells and photosensitive ganglion cells of the retina of the eye. This cycle was elucidated by George Wald (1906-1997) for
Schematic diagram of the human ear Hearing, or auditory perception, is the ability to perceive sound by detecting vibrations, changes in the pressure of the surrounding medium through time, through an organ such as the ear. Background Sound may be heard through solid, liquid, or gaseous matter. It is one of the traditional
The international symbol of deafness and hearing loss Hearing loss, also known as hearing impairment, is a partial or total inability to hear. A deaf person has little to no hearing. Hearing loss may occur in one or both ears. In children hearing problems can affect the ability to learn spoken language and in
In psychophysics, auditory scene analysis (ASA) is a proposed model for the basis of auditory perception. This is understood as the process by which the human auditory system organizes sound into perceptually meaningful elements. The term was coined by psychologist Albert Bregman. The related concept in machine perception is computational auditory scene analysis (CASA), which
The auditory system is the sensory system for the sense of hearing. It includes both the sensory organs (the ears) and the auditory parts of the sensory system. System overview The outer ear funnels sound vibrations to the eardrum, increasing the sound pressure in the middle frequency range. The middle-ear ossicles further amplify the
A consumer stereo bone conduction headset. The two transducers fit slightly in front of the ears. Bone conduction is the conduction of sound to the inner ear through the bones of the skull. Bone conduction transmission can be used with individuals with normal or impaired hearing. Overview Bone conduction is one reason why
Hearing range describes the range of frequencies that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, though there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to
Human echolocation is the ability of humans to detect objects in their environment by sensing echoes from those objects, by actively creating sounds – for example, by tapping their canes, lightly stomping their foot, snapping their fingers, or making clicking noises with their mouths – people trained to orient by echolocation can interpret the sound
The neuronal encoding of sound is the representation of auditory sensation and perception in the nervous system. This article explores the basic physiological principles of sound perception, and traces hearing mechanisms from sound as pressure waves in air to the transduction of these waves into electrical impulses (action potentials) along auditory nerve fibers, and further
Taste bud Taste, gustatory perception, or gustation is one of the five traditional senses that belongs to the gustatory system. Taste is the sensation produced when a substance in the mouth reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue. Taste, along with smell (olfaction)
Thermoception or thermoreception is the sense by which an organism perceives temperatures. The details of how temperature receptors work are still being investigated. Ciliopathy is associated with decreased ability to sense heat, thus cilia may aid in the process. Transient receptor potential channels (TRP channels) are believed to play a role in many species in
The cerebellum is largely responsible for coordinating the unconscious aspects of proprioception. Proprioception (/ˌproʊprioʊˈsɛpʃən, -priə-/ PRO-pree-o-SEP-shən), from Latin proprius, meaning “one’s own”, “individual”, and capio, capere, to take or grasp, is the sense of the relative position of one’s own parts of the body and strength of effort being employed in movement. In humans
Nociception (also nocioception or nociperception, from Latin nocere ‘to harm or hurt’) is the sensory nervous system’s response to certain harmful or potentially harmful stimuli. In nociception, intense chemical (e.g., chili powder in the eyes), mechanical (e.g., cutting, crushing), or thermal (heat and cold) stimulation of sensory nerve cells called nociceptors produces a signal that
Balance skill development in children Sense of balance or equilibrioception is one of the physiological senses related to balance. It helps prevent humans and animals from falling over when standing or moving. Balance is the result of a number of body systems working together: the eyes (visual system), ears (vestibular system) and the body’s
A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. Normally there are four main types in glabrous mammalian skin: lamellar corpuscles, tactile corpuscles, Merkel nerve endings, and bulbous corpuscles. There are also mechanoreceptors in hairy skin, and the hair cells in thoreceptors of primates like rhesus monkeys and other mammals are
A chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces (responds to) a chemical substance (endogenous or induced) and generates a biological signal. This signal may be in the form of an action potential if the chemoreceptor is a neuron (nerve cell), or in the form of a neurotransmitter that can
The vestibular system, in most mammals, is the sensory system that provides the leading contribution to the sense of balance and spatial orientation for the purpose of coordinating movement with balance. Together with the cochlea, a part of the auditory system, it constitutes the labyrinth of the inner ear in most mammals. As movements consist
Interoception is involved in many different physiological systems like the cardiorespiratory system, gastrointestinal system, nociceptive system, endocrine and immune systems. Interoception is contemporarily defined as the sense of the internal state of the body. It encompasses the brain’s process of integrating signals relayed from the body into specific subregions—like the brainstem, thalamus, insula, somatosensory
Hunger and satiety are sensations. Hunger represents the physiological need to eat food. Satiety is the absence of hunger; it is the sensation of feeling full. Appetite is another sensation experienced with eating; it is the desire to eat food. There are several theories about how the feeling of hunger arises. A healthy, well-nourished individual
Peripheral chemoreceptors (of the carotid and aortic bodies) are so named because they are sensory extensions of the peripheral nervous system into blood vessels where they detect changes in chemical concentrations. As transducers of patterns of variability in the surrounding environment, carotid and aortic bodies count as chemosensors in a similar way as taste buds