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Disconnection Syndrome
Disconnection syndrome is a general term for a collection of neurological symptoms caused – via lesions to associational or commissural nerve fibres – by damage to the white matter axons of communication pathways in the cerebrum (not to be confused with the cerebellum), independent of any lesions to the cortex. The behavioral effects of such disconnections are relatively predictable in adults. Disconnection syndromes usually reflect circumstances where regions A and B still have their functional specializations except in domains that depend on the interconnections between the two regions. Callosal syndrome, or split-brain, is an example of a disconnection syndrome from damage to the corpus callosum between the two hemispheres of the brain. Disconnection syndrome can also lead to aphasia, left-sided apraxia, and tactile aphasia, among other symptoms. Other types of disconnection syndrome include conduction aphasia (lesion of the association tract connecting Broca’s area and W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTI Brain Tractographic Image A Panal
DTI may refer to: Science and technology * Deep trench isolation; See Shallow trench isolation * Dial test indicator * Direct trader input, in the history of electronic data interchange * Diffusion tensor imaging, a structural medical imaging technique * Direct thrombin inhibitor * Diesel turbo injection, a brand name for common rail * Direct tension indicator * Deep tissue injury, see suspected deep tissue injury in List of medical abbreviations: S * Dye transfer inhibitor Organizations * Defence Technology Institute, the Thai defence technology public organisation * Department of Trade and Industry (other), a government department in several countries * Detroit, Toledo and Ironton Railroad * Diversified Technology, Inc. * Directorate of Terrorist Identities, responsible for the Terrorist Identities Datamart Environment Other uses * Debt-to-income ratio In the consumer mortgage industry, debt-to-income ratio (often abbreviated DTI) is the percentage of a consume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfaction
The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory system. Glomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion. There are many different causes for alteration, lack, or disturbance to a normal sense of smell, and can include damage to the nose or smell receptors, or central problems affecting the brain. Some causes include upper respiratory infections, traumatic brain injury, and neurodegenerative disease. History of study Early scientific study of the sense of smell includes the extensive doctoral dissertation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman Geschwind
Norman Geschwind (January 8, 1926 – November 4, 1984) was a pioneering American Behavioral neurology, behavioral neurologist, best known for his exploration of behavioral neurology through disconnection models based on lesion analysis. Early life Norman Geschwind was born on January 8, 1926, in New York City, New York to a Jewish family. He was a student at Boy's High School in Brooklyn, New York. He matriculated into Harvard University in 1942, initially planning to study mathematics. His education was interrupted when drafted into the Army in 1944. After serving for two years, he returned to Harvard University in 1946. Geschwind changed to the Department of Social Relations and studied a combination of social/personality psychology and cultural anthropology. Geschwind later married and had three children, Naomi, David, and Claudia. Medical education and training Geschwind attended Harvard Medical School, intending to become a psychiatrist. His emphasis began to shift after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemianopia
Hemianopsia, or hemianopia, is a loss of vision or blindness (anopsia) in half the visual field, usually on one side of the vertical midline. The most common causes of this damage are stroke, brain tumor, and trauma. This article deals only with permanent hemianopsia, and not with transitory or temporary hemianopsia, as identified by William Wollaston PRS in 1824. Temporary hemianopsia can occur in the aura phase of migraine. Etymology The word ''hemianopsia'' is from Greek origins, where: * ''hemi'' means "half", * ''an'' means "without", and * ''opsia'' means "seeing". Types When the pathology involves both eyes, it is either homonymous or heteronymous. Homonymous hemianopsia Paris as seen with left homonymous hemianopsia. A homonymous hemianopsia is the loss of half of the visual field on the same side in both eyes. The visual images that we see to the right side travel from both eyes to the left side of the brain, while the visual images we see to the left sid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Agnosia
Visual agnosia is an impairment in recognition of visually presented objects. It is not due to a deficit in vision (acuity, visual field, and scanning), language, memory, or intellect. While cortical blindness results from lesions to primary visual cortex, visual agnosia is often due to damage to more anterior cortex such as the posterior occipital and/or temporal lobe(s) in the brain. /sup> There are two types of visual agnosia: apperceptive agnosia and associative agnosia. Recognition of visual objects occurs at two primary levels. At an apperceptive level, the features of the visual information from the retina are put together to form a perceptual representation of an object. At an associative level, the meaning of an object is attached to the perceptual representation and the object is identified. If a person is unable to recognize objects because they cannot perceive correct forms of the objects, although their knowledge of the objects is intact (i.e. they do not have anomia), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcuate Fasciculus
The arcuate fasciculus (AF) is a bundle of axons that generally connects the Broca's area and the Wernicke's area in the brain. It is an association fiber tract connecting caudal temporal cortex and inferior frontal lobe. ''Fasciculus arcuatus'' is Latin for curved bundle. Structure The arcuate fasciculus is a white matter tract that runs parallel to the superior longitudinal fasciculus. Due to their proximity, some researchers refer to them interchangeably. They can be distinguished by the location and function of their endpoints in the frontal cortex. The arcuate fasciculus terminates in Broca's area (specifically BA 44) which is linked to processing complex syntax. However, the superior longitudinal fasciculus ends in the premotor cortex which is implicated in acoustic-motor mapping. Connection Historically, the arcuate fasciculus has been understood to connect two important areas for language use: Broca's area in the inferior frontal gyrus and Wernicke's area in the poste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conduction Aphasia
Conduction aphasia, also called associative aphasia, is an uncommon form of difficulty in speaking (aphasia). It is caused by damage to the parietal lobe of the brain. An acquired language disorder, it is characterised by intact auditory comprehension, coherent (yet paraphasic) speech production, but poor speech repetition. Affected people are fully capable of understanding what they are hearing, but fail to encode phonological information for production. This deficit is load-sensitive as the person shows significant difficulty repeating phrases, particularly as the phrases increase in length and complexity and as they stumble over words they are attempting to pronounce.Conduction Aphasia. (n.d.). Retrieved from http://www.asha.org/Glossary/Conduction-Aphasia/ People have frequent errors during spontaneous speech, such as substituting or transposing sounds. They are also aware of their errors and will show significant difficulty correcting them. For example: In 1970, Tim Shall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Wernicke
Carl (or Karl) Wernicke (; ; 15 May 1848 – 15 June 1905) was a German physician, anatomist, psychiatrist and neuropathologist. He is known for his influential research into the pathological effects of specific forms of encephalopathy and also the study of receptive aphasia, both of which are commonly associated with Wernicke's name and referred to as Wernicke encephalopathy and Wernicke's aphasia, respectively. His research, along with that of Paul Broca, led to groundbreaking realizations of the localization of brain function, specifically in speech. As such, Wernicke's area (a.k.a. Wernicke's Speech Area) has been named after the scientist. Biography Wernicke was born on May 15, 1848, in Tarnowitz, a small town in Upper Silesia, Prussia, now Tarnowskie Góry, Poland. He obtained his secondary education at the gymnasium in Oppeln, which is a school near the university of Breslau. Wernicke then studied medicine at the University of Breslau and did graduate work studying langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agraphia
Agraphia is an acquired neurological disorder causing a loss in the ability to communicate through writing, either due to some form of motor dysfunction or an inability to spell. The loss of writing ability may present with other language or neurological disorders; disorders appearing commonly with agraphia are alexia, aphasia, dysarthria, agnosia, acalculia and apraxia. The study of individuals with agraphia may provide more information about the pathways involved in writing, both language related and motoric. Agraphia cannot be directly treated, but individuals can learn techniques to help regain and rehabilitate some of their previous writing abilities. These techniques differ depending on the type of agraphia. Agraphia can be broadly divided into central and peripheral categories. Central agraphias typically involve language areas of the brain, causing difficulty spelling or with spontaneous communication, and are often accompanied by other language disorders. Peripheral agr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apraxia
Apraxia is a motor disorder caused by damage to the brain (specifically the posterior parietal cortex or corpus callosum), which causes difficulty with motor planning to perform tasks or movements. The nature of the damage determines the disorder's severity, and the absence of sensory loss or paralysis helps to explain the level of difficulty. Children may be born with apraxia; its cause is unknown, and symptoms are usually noticed in the early stages of development. Apraxia occurring later in life, known as ''acquired apraxia'', is typically caused by traumatic brain injury, stroke, dementia, Alzheimer's disease, brain tumor, or other neurodegenerative disorders. The multiple types of apraxia are categorized by the specific ability and/or body part affected. The term "apraxia" comes from the Greek ἀ- ''a-'' ("without") and πρᾶξις ''praxis'' ("action"). Types The several types of apraxia include: * Apraxia of speech (AOS) is having difficulty planning and coordinating the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor System
The motor system is the set of central and peripheral structures in the nervous system that support motor functions, i.e. movement. Peripheral structures may include skeletal muscles and neural connections with muscle tissues. Central structures include cerebral cortex, brainstem, spinal cord, pyramidal system including the upper motor neurons, extrapyramidal system, cerebellum, and the lower motor neurons in the brainstem and the spinal cord. Pyramidal motor system The pyramidal motor system, also called the pyramidal tract or the corticospinal tract, start in the motor center of the cerebral cortex.Rizzolatti G, Luppino G (2001) The Cortical Motor System. ''Neuron'' 31: 889-90SD/ref> There are upper and lower motor neurons in the corticospinal tract. The motor impulses originate in the giant pyramidal cells or Betz cells of the motor area; i.e., precentral gyrus of cerebral cortex. These are the upper motor neurons (UMN) of the corticospinal tract. The axons of these cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audition
An audition is a sample performance by an actor, singer, musician, dancer or other performer. It typically involves the performer displaying their talent through a previously memorized and rehearsed solo piece or by performing a work or piece given to the performer at the audition or shortly before. In some cases, such as with a model or acrobat, the individual may be asked to demonstrate a range of professional skills. Actors may be asked to present a monologue. Singers will perform a song in a popular music context or an aria in a Classical context. A dancer will present a routine in a specific style, such as ballet, tap dance or hip-hop, or show his or her ability to quickly learn a choreographed dance piece. The audition is a systematic process in which industry professionals select performers, which is in some ways analogous to a job interview in the regular job market. In an audition, the employer is testing the ability of the applicant to meet the needs of the job and asse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
