Wernicke Encephalopathy: An acute neurological disorder characterized by the triad of ophthalmoplegia, ataxia, and disturbances of mental activity or consciousness. Eye movement abnormalities include nystagmus, external rectus palsies, and reduced conjugate gaze. THIAMINE DEFICIENCY and chronic ALCOHOLISM are associated conditions. Pathologic features include periventricular petechial hemorrhages and neuropil breakdown in the diencephalon and brainstem. Chronic thiamine deficiency may lead to KORSAKOFF SYNDROME. (Adams et al., Principles of Neurology, 6th ed, pp1139-42; Davis & Robertson, Textbook of Neuropathology, 2nd ed, pp452-3)Aphasia: A cognitive disorder marked by an impaired ability to comprehend or express language in its written or spoken form. This condition is caused by diseases which affect the language areas of the dominant hemisphere. Clinical features are used to classify the various subtypes of this condition. General categories include receptive, expressive, and mixed forms of aphasia.Thiamine Deficiency: A nutritional condition produced by a deficiency of THIAMINE in the diet, characterized by anorexia, irritability, and weight loss. Later, patients experience weakness, peripheral neuropathy, headache, and tachycardia. In addition to being caused by a poor diet, thiamine deficiency in the United States most commonly occurs as a result of alcoholism, since ethanol interferes with thiamine absorption. In countries relying on polished rice as a dietary staple, BERIBERI prevalence is very high. (From Cecil Textbook of Medicine, 19th ed, p1171)Aphasia, Primary Progressive: A progressive form of dementia characterized by the global loss of language abilities and initial preservation of other cognitive functions. Fluent and nonfluent subtypes have been described. Eventually a pattern of global cognitive dysfunction, similar to ALZHEIMER DISEASE, emerges. Pathologically, there are no Alzheimer or PICK DISEASE like changes, however, spongiform changes of cortical layers II and III are present in the TEMPORAL LOBE and FRONTAL LOBE. (From Brain 1998 Jan;121(Pt 1):115-26)Thiamine: 3-((4-Amino-2-methyl-5-pyrimidinyl)methyl)-5-(2- hydroxyethyl)-4-methylthiazolium chloride.Thyroid Crisis: A dangerous life-threatening hypermetabolic condition characterized by high FEVER and dysfunction of the cardiovascular, the nervous, and the gastrointestinal systems.Aphasia, Wernicke: Impairment in the comprehension of speech and meaning of words, both spoken and written, and of the meanings conveyed by their grammatical relationships in sentences. It is caused by lesions that primarily affect Wernicke's area, which lies in the posterior perisylvian region of the temporal lobe of the dominant hemisphere. (From Brain & Bannister, Clinical Neurology, 7th ed, p141; Kandel et al., Principles of Neural Science, 3d ed, p846)Anomia: A language dysfunction characterized by the inability to name people and objects that are correctly perceived. The individual is able to describe the object in question, but cannot provide the name. This condition is associated with lesions of the dominant hemisphere involving the language areas, in particular the TEMPORAL LOBE. (From Adams et al., Principles of Neurology, 6th ed, p484)Aphasia, Conduction: A type of fluent aphasia characterized by an impaired ability to repeat one and two word phrases, despite retained comprehension. This condition is associated with dominant hemisphere lesions involving the arcuate fasciculus (a white matter projection between Broca's and Wernicke's areas) and adjacent structures. Like patients with Wernicke aphasia (APHASIA, WERNICKE), patients with conduction aphasia are fluent but commit paraphasic errors during attempts at written and oral forms of communication. (From Adams et al., Principles of Neurology, 6th ed, p482; Brain & Bannister, Clinical Neurology, 7th ed, p142; Kandel et al., Principles of Neural Science, 3d ed, p848)Language: A verbal or nonverbal means of communicating ideas or feelings.Thyrotoxicosis: A hypermetabolic syndrome caused by excess THYROID HORMONES which may come from endogenous or exogenous sources. The endogenous source of hormone may be thyroid HYPERPLASIA; THYROID NEOPLASMS; or hormone-producing extrathyroidal tissue. Thyrotoxicosis is characterized by NERVOUSNESS; TACHYCARDIA; FATIGUE; WEIGHT LOSS; heat intolerance; and excessive SWEATING.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Primary Progressive Nonfluent Aphasia: A form of frontotemporal lobar degeneration and a progressive form of dementia characterized by motor speech impairment and AGRAMMATISM, with relative sparing of single word comprehension and semantic memory.Language Tests: Tests designed to assess language behavior and abilities. They include tests of vocabulary, comprehension, grammar and functional use of language, e.g., Development Sentence Scoring, Receptive-Expressive Emergent Language Scale, Parsons Language Sample, Utah Test of Language Development, Michigan Language Inventory and Verbal Language Development Scale, Illinois Test of Psycholinguistic Abilities, Northwestern Syntax Screening Test, Peabody Picture Vocabulary Test, Ammons Full-Range Picture Vocabulary Test, and Assessment of Children's Language Comprehension.Speech Therapy: Treatment for individuals with speech defects and disorders that involves counseling and use of various exercises and aids to help the development of new speech habits.Language Therapy: Rehabilitation of persons with language disorders or training of children with language development disorders.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Agraphia: Loss or impairment of the ability to write (letters, syllables, words, or phrases) due to an injury to a specific cerebral area or occasionally due to emotional factors. This condition rarely occurs in isolation, and often accompanies APHASIA. (From Adams et al., Principles of Neurology, 6th ed, p485; APA, Thesaurus of Psychological Index Terms, 1994)Alcoholism: A primary, chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. The disease is often progressive and fatal. It is characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking, most notably denial. Each of these symptoms may be continuous or periodic. (Morse & Flavin for the Joint Commission of the National Council on Alcoholism and Drug Dependence and the American Society of Addiction Medicine to Study the Definition and Criteria for the Diagnosis of Alcoholism: in JAMA 1992;268:1012-4)Apraxias: A group of cognitive disorders characterized by the inability to perform previously learned skills that cannot be attributed to deficits of motor or sensory function. The two major subtypes of this condition are ideomotor (see APRAXIA, IDEOMOTOR) and ideational apraxia, which refers to loss of the ability to mentally formulate the processes involved with performing an action. For example, dressing apraxia may result from an inability to mentally formulate the act of placing clothes on the body. Apraxias are generally associated with lesions of the dominant PARIETAL LOBE and supramarginal gyrus. (From Adams et al., Principles of Neurology, 6th ed, pp56-7)Semantics: The relationships between symbols and their meanings.Speech: Communication through a system of conventional vocal symbols.Language Disorders: Conditions characterized by deficiencies of comprehension or expression of written and spoken forms of language. These include acquired and developmental disorders.Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Dyslexia, Acquired: A receptive visual aphasia characterized by the loss of a previously possessed ability to comprehend the meaning or significance of handwritten words, despite intact vision. This condition may be associated with posterior cerebral artery infarction (INFARCTION, POSTERIOR CEREBRAL ARTERY) and other BRAIN DISEASES.Quercetin: A flavonol widely distributed in plants. It is an antioxidant, like many other phenolic heterocyclic compounds. Glycosylated forms include RUTIN and quercetrin.Democracy: A system of government in which there is free and equal participation by the people in the political decision-making process.Split-Brain Procedure: Complete severing of the CORPUS CALLOSUM. In humans it is usually performed to treat medically intractable, multifocal EPILEPSY. EXPERIMENTAL ANIMAL MODELS of split brain preparations are used in research.Corpus Callosum: Broad plate of dense myelinated fibers that reciprocally interconnect regions of the cortex in all lobes with corresponding regions of the opposite hemisphere. The corpus callosum is located deep in the longitudinal fissure.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Agenesis of Corpus Callosum: Birth defect that results in a partial or complete absence of the CORPUS CALLOSUM. It may be isolated or a part of a syndrome (e.g., AICARDI'S SYNDROME; ACROCALLOSAL SYNDROME; ANDERMANN SYNDROME; and HOLOPROSENCEPHALY). Clinical manifestations include neuromotor skill impairment and INTELLECTUAL DISABILITY of variable severity.Epilepsy: A disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. Epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (From Adams et al., Principles of Neurology, 6th ed, p313)Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Psychosurgery: Treatment of chronic, severe and intractable psychiatric disorders by surgical removal or interruption of certain areas or pathways in the brain, especially in the prefrontal lobes.Daucus carota: A plant species of the family APIACEAE that is widely cultivated for the edible yellow-orange root. The plant has finely divided leaves and flat clusters of small white flowers.Frustration: The motivational and/or affective state resulting from being blocked, thwarted, disappointed or defeated.Ants: Insects of the family Formicidae, very common and widespread, probably the most successful of all the insect groups. All ants are social insects, and most colonies contain three castes, queens, males, and workers. Their habits are often very elaborate and a great many studies have been made of ant behavior. Ants produce a number of secretions that function in offense, defense, and communication. (From Borror, et al., An Introduction to the Study of Insects, 4th ed, p676)Neurology: A medical specialty concerned with the study of the structures, functions, and diseases of the nervous system.Aphasia, Broca: An aphasia characterized by impairment of expressive LANGUAGE (speech, writing, signs) and relative preservation of receptive language abilities (i.e., comprehension). This condition is caused by lesions of the motor association cortex in the FRONTAL LOBE (BROCA AREA and adjacent cortical and white matter regions).Catatonia: A neuropsychiatric disorder characterized by one or more of the following essential features: immobility, mutism, negativism (active or passive refusal to follow commands), mannerisms, stereotypies, posturing, grimacing, excitement, echolalia, echopraxia, muscular rigidity, and stupor; sometimes punctuated by sudden violent outbursts, panic, or hallucinations. This condition may be associated with psychiatric illnesses (e.g., SCHIZOPHRENIA; MOOD DISORDERS) or organic disorders (NEUROLEPTIC MALIGNANT SYNDROME; ENCEPHALITIS, etc.). (From DSM-IV, 4th ed, 1994; APA, Thesaurus of Psychological Index Terms, 1994)Repetition Priming: A type of procedural memory manifested as a change in the ability to identify an item as a result of a previous encounter with the item or stimuli.Naphthacenes: Polyacenes with four ortho-fused benzene rings in a straight linear arrangement. This group is best known for the subclass called TETRACYCLINES.Exercise Therapy: A regimen or plan of physical activities designed and prescribed for specific therapeutic goals. Its purpose is to restore normal musculoskeletal function or to reduce pain caused by diseases or injuries.Otolithic Membrane: A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.Nervous System Diseases: Diseases of the central and peripheral nervous system. This includes disorders of the brain, spinal cord, cranial nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular junction, and muscle.Trigeminal Nerve: The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.Speech-Language Pathology: The study of speech or language disorders and their diagnosis and correction.Echolalia: Involuntary ("parrot-like"), meaningless repetition of a recently heard word, phrase, or song. This condition may be associated with transcortical APHASIA; SCHIZOPHRENIA; or other disorders. (From Adams et al., Principles of Neurology, 6th ed, p485)Speech Perception: The process whereby an utterance is decoded into a representation in terms of linguistic units (sequences of phonetic segments which combine to form lexical and grammatical morphemes).Speech Disorders: Acquired or developmental conditions marked by an impaired ability to comprehend or generate spoken forms of language.Speech Intelligibility: Ability to make speech sounds that are recognizable.Speech Acoustics: The acoustic aspects of speech in terms of frequency, intensity, and time.