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Cortical Homunculus
A cortical homunculus () is a distorted representation of the human body, based on a neurological "map" of the areas and portions of the human brain dedicated to processing motor functions, and/or sensory functions, for different parts of the body. Nerve fibresconducting somatosensory information from all over the bodyterminate in various areas of the parietal lobe in the cerebral cortex, forming a representational map of the body. Findings from the 2010s and early 2020s began to call for a revision of the traditional "homunculus" model and a new interpretation of the internal body map (likely less simplistic and graphic), and research is ongoing in this field. Types Motor homunculus A motor homunculus represents a map of brain areas dedicated to ''motor'' processing for different anatomical divisions of the body. The primary motor cortex is located in the precentral gyrus, and handles signals coming from the premotor area of the frontal lobe The frontal lobe i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensory Homunculus-en
Sensory may refer to: Biology * Sensory ecology, how organisms obtain information about their environment * Sensory neuron, nerve cell responsible for transmitting information about external stimuli * Sensory perception, the process of acquiring and interpreting sensory information * Sensory receptor, a structure that recognizes external stimuli * Sensory system, part of the nervous system of organisms Business and brands * Sensory, Inc., an American speech technology company Other uses * Sensory analysis, a consumer product-testing method * Sensory garden, a self-contained garden area that allows visitors to enjoy a wide variety of sensory experiences * Sensory play, an act where senses are engaged to increase erotic pleasure See also * Sensor A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamus
The thalamus (: thalami; from Greek language, Greek Wikt:θάλαμος, θάλαμος, "chamber") is a large mass of gray matter on the lateral wall of the third ventricle forming the wikt:dorsal, dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, known as the thalamocortical radiations, allowing hub (network science), hub-like exchanges of information. It has several functions, such as the relaying of sensory neuron, sensory and motor neuron, motor signals to the cerebral cortex and the regulation of consciousness, sleep, and alertness. Anatomically, the thalami are paramedian symmetrical structures (left and right), within the vertebrate brain, situated between the cerebral cortex and the midbrain. It forms during embryonic development as the main product of the diencephalon, as first recognized by the Swiss embryologist and anatomist Wilhelm His Sr. in 1893. Anatomy The thalami ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensory Systems
The sensory nervous system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory neurons (including the sensory receptor cells), neural pathways, and parts of the brain involved in sensory perception and interoception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, balance and visceral sensation. Sense organs are transducers that convert data from the outer physical world to the realm of the mind where people interpret the information, creating their perception of the world around them. The receptive field is the area of the body or environment to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field. Receptive fields have been identified for the visual system, auditory system and somatosensory system. Senses and receptors Whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole-rat
Mole-rat or mole rat can refer to several groups of burrowing Old World rodents: * Bathyergidae, a family of about 20 hystricognath species in six genera from Africa also called blesmols. *'' Heterocephalus glaber'', the naked mole-rat. * Spalacidae, a family of about 30 muroid species in six genera from Eurasia and northeast Africa, including: **'' Tachyoryctes'', a genus of about 15 species from Africa; ** Blind mole rats (Spalacinae), a subfamily of about 15 living species in the genus '' Spalax'' from southeastern Europe, southwestern Asia, and northeastern Africa; ** Zokors (Myospalacinae), occasionally called mole-rats, about eight species from central and eastern Asia. * In the family Muridae The Muridae, or murids, are either the largest or second-largest family of rodents and of mammals, containing approximately 870 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. ...: ** '' Nesokia indica'' from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topographic Map (neuroanatomy)
In neuroanatomy, topographic map is the ordered projection of a sensory surface (like the retina or the skin) or an effector system (like the musculature) to one or more structures of the central nervous system. Topographic maps can be found in all sensory systems and in many motor systems. Visual system The visual system refers to the part of the central nervous system that allows an organism to see. It interprets information from visible light to build a representation of the world. The ganglion cells of the retina project in an orderly fashion to the lateral geniculate nucleus (LGN) of the thalamus and from there to the primary visual cortex (V1); adjacent spots on the retina are represented by adjacent neurons in the lateral geniculate nucleus and the primary visual cortex. The term for this pattern of projection is ''topography''. There are many types of topographic maps in the visual cortices, including retinotopic maps, ocular dominance maps and orientation maps. Retinotop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatotopic Arrangement
Somatotopy is the point-for-point correspondence of an area of the body to a specific point on the central nervous system. Typically, the area of the body corresponds to a point on the primary somatosensory cortex (postcentral gyrus). This cortex is typically represented as a sensory homunculus which orients the specific body parts and their respective locations upon the homunculus. Areas such as the appendages, digits, penis, and face can draw their sensory locations upon the somatosensory cortex. The areas which are finely controlled (e.g., the digits) have larger portions of the somatosensory cortex whereas areas which are coarsely controlled (e.g., the trunk) have smaller portions. Areas such as the viscera do not have sensory locations on the postcentral gyrus. Macaques, a kind of monkey, already exhibit somatotopy in their somatosensory and motor systems at birth. Sensorimotor mapping of the human cerebellum Functional magnetic resonance imaging (fMRI) was employed to det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embodied Cognition
Embodied cognition represents a diverse group of theories which investigate how cognition is shaped by the bodily state and capacities of the organism. These embodied factors include the motor system, the perceptual system, bodily interactions with the environment (situatedness), and the assumptions about the world that shape the functional structure of the brain and body of the organism. Embodied cognition suggests that these elements are essential to a wide spectrum of cognitive functions, such as perception biases, memory recall, comprehension and high-level mental constructs (such as meaning attribution and Categorization, categories) and performance on various cognitive tasks (reasoning or judgment). The embodied mind thesis challenges other theories, such as Cognitivism (psychology), cognitivism, computationalism, and Dualism (philosophy of mind), Cartesian dualism. It is closely related to the extended mind thesis, situated cognition, and enactivism. The modern version dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Motor Cortex
The primary motor cortex ( Brodmann area 4) is a brain region that in humans is located in the dorsal portion of the frontal lobe. It is the primary region of the motor system and works in association with other motor areas including premotor cortex, the supplementary motor area, posterior parietal cortex, and several subcortical brain regions, to plan and execute voluntary movements. Primary motor cortex is defined anatomically as the region of cortex that contains large neurons known as Betz cells, which, along with other cortical neurons, send long axons down the spinal cord to synapse onto the interneuron circuitry of the spinal cord and also directly onto the alpha motor neurons in the spinal cord which connect to the muscles. At the primary motor cortex, motor representation is orderly arranged (in an inverted fashion) from the toe (at the top of the cerebral hemisphere) to mouth (at the bottom) along a fold in the cortex called the central sulcus. However, some body p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Magnetic Resonance Imaging
Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. The primary form of fMRI uses the blood-oxygen-level dependent (BOLD) contrast, discovered by Seiji Ogawa in 1990. This is a type of specialized brain and body scan used to map neuron, neural activity in the brain or spinal cord of humans or other animals by imaging the change in blood flow (hemodynamic response) related to energy use by brain cells. Since the early 1990s, fMRI has come to dominate brain mapping research because it does not involve the use of injections, surgery, the ingestion of substances, or exposure to ionizing radiation. This measure is frequently corrupted by noise from various sources; hence, statistical procedures are used to extract the underlying si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatotopic Arrangement
Somatotopy is the point-for-point correspondence of an area of the body to a specific point on the central nervous system. Typically, the area of the body corresponds to a point on the primary somatosensory cortex (postcentral gyrus). This cortex is typically represented as a sensory homunculus which orients the specific body parts and their respective locations upon the homunculus. Areas such as the appendages, digits, penis, and face can draw their sensory locations upon the somatosensory cortex. The areas which are finely controlled (e.g., the digits) have larger portions of the somatosensory cortex whereas areas which are coarsely controlled (e.g., the trunk) have smaller portions. Areas such as the viscera do not have sensory locations on the postcentral gyrus. Macaques, a kind of monkey, already exhibit somatotopy in their somatosensory and motor systems at birth. Sensorimotor mapping of the human cerebellum Functional magnetic resonance imaging (fMRI) was employed to det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilder Penfield
Wilder Graves Penfield (January 26, 1891April 5, 1976) was an American-Canadian neurosurgeon. He expanded brain surgery's methods and techniques, including mapping the functions of various regions of the brain such as the cortical homunculus. His scientific contributions on neural stimulation expand across a variety of topics including hallucinations, illusions, dissociation and ''déjà vu''. Penfield devoted much of his thinking to mental processes, including contemplation of whether there was any scientific basis for the existence of the human soul. Life and career Early life and education Born in Spokane, Washington, on January 26, 1891, Penfield spent most of his early life in Hudson, Wisconsin. He studied at Princeton University, where he was a member of Cap and Gown Club and played on the football team. After graduation in 1913, he was hired briefly as the team coach. In 1915 he obtained a Rhodes Scholarship to Merton College, Oxford, where he studied neuropatho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensory And Motor Homunculi
Sensory may refer to: Biology * Sensory ecology, how organisms obtain information about their environment * Sensory neuron, nerve cell responsible for transmitting information about external stimuli * Sensory perception, the process of acquiring and interpreting sensory information * Sensory receptor, a structure that recognizes external stimuli * Sensory system, part of the nervous system of organisms Business and brands * Sensory, Inc., an American speech technology company Other uses * Sensory analysis, a consumer product-testing method * Sensory garden, a self-contained garden area that allows visitors to enjoy a wide variety of sensory experiences * Sensory play, an act where senses are engaged to increase erotic pleasure See also * Sensor A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
