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Agnōsía
Agnosia is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually associated with brain injury or neurological illness, particularly after damage to the occipitotemporal border, which is part of the ventral stream. Agnosia only affects a single modality, such as vision or hearing. More recently, a top-down interruption is considered to cause the disturbance of handling perceptual information. Types Visual agnosia Visual agnosia is a broad category that refers to a deficiency in the ability to recognize visual objects. Visual agnosia can be further subdivided into two different subtypes: apperceptive visual agnosia and associative visual agnosia. Individuals with apperceptive visual agnosia display the ability to see contours and outlines when shown an object, but they experience difficulty if ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosopagnosia
Prosopagnosia (from Greek ''prósōpon'', meaning "face", and ''agnōsía'', meaning "non-knowledge"), also called face blindness, ("illChoisser had even begun tpopularizea name for the condition: 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 term originally referred to a condition following acute brain damage (acquired prosopagnosia), but a congenital or developmental form of the disorder also exists, with a prevalence of 2.5%. The brain area usually associated with prosopagnosia is the fusiform gyrus, which activates specifically in response to faces. The functionality of the fusiform gyrus allows most people to recognize faces in more detail than they do similarly complex inanimate objects. For those with prosopagno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Agnosia
Auditory agnosia is a form of agnosia that manifests itself primarily in the inability to recognize or differentiate between sounds. It is not a defect of the ear or "hearing", but rather a neurological inability of the brain to process sound meaning. While auditory agnosia impairs the understanding of sounds, other abilities such as reading, writing, and speaking are not hindered. It is caused by bilateral damage to the anterior superior temporal gyrus, which is part of the auditory pathway responsible for sound recognition, the auditory "what" pathway. Persons with auditory agnosia can physically hear the sounds and describe them using unrelated terms, but are unable to recognize them. They might describe the sound of some environmental sounds, such as a motor starting, as resembling a lion roaring, but would not be able to associate the sound with "car" or "engine", nor would they say that it ''was'' a lion creating the noise. All auditory agnosia patients read lips in order to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonagnosia
Phonagnosia (from Ancient Greek φωνή ''phone'', "voice" and γνῶσις ''gnosis'', "knowledge") is a type of agnosia, or loss of knowledge, that involves a disturbance in the recognition of familiar voices and the impairment of voice discrimination abilities in which the affected individual does not suffer from comprehension deficits. Phonagnosia is an auditory agnosia, an acquired auditory processing disorder resulting from brain damage, other auditory agnosias include cortical deafness and auditory verbal agnosia also known as pure word deafness. Since people suffering from phonagnosia do not suffer from aphasia, it is suggested that the structures of linguistic comprehension are functionally separate from those of the perception of the identity of the speaker who produced it. History Phonagnosia is the auditory equivalent of prosopagnosia. Unlike prosopagnosia, investigations of phonagnosia have not been extensively pursued. Phonagnosia was first described by a study by Van ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital Analgesia
Congenital insensitivity to pain (CIP), also known as congenital analgesia, is one or more extraordinarily rare conditions in which a person cannot feel (and has never felt) physical pain. The conditions described here are separate from the HSAN group of disorders, which have more specific signs and cause. Because feeling physical pain is vital for survival, CIP is an extremely dangerous condition. It is common for people with the condition to die in childhood due to injuries or illnesses going unnoticed. Burn injuries are among the more common injuries. Signs and symptoms For people with this disorder, cognition and sensation are otherwise normal; for instance, patients can still feel discriminative touch (though not always temperature), and there are generally no detectable physical abnormalities. Because children and adults with the disorder cannot feel pain, they may not respond to problems, thus being at a higher risk of more severe diseases. Children with this condition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrative Agnosia
Integrative agnosia is a sub-disease of agnosia, meaning the lack of integrating perceptual wholes within knowledge. Integrative agnosia can be assessed by several experimental tests such as the Efron shape test, which determines the specificity of the disease being Integrative. This disease is often caused by brain trauma, producing medial ventral lesions to the extrastriate cortex. Affecting this region of the brain produces learning impairments: the inability to integrate parts such as spatial distances or producing visual images from short or long-term memory. Symptoms and signs Symptoms generally include memory or learning impairments, with the inability to integrate parts coherently. There is a big range to the severity of this disease and often the symptoms that are shown in each patient vary as well. As ambiguous as the general symptoms may be, patients are often treated of their respective symptoms as they appear and how critical the conditions are. Causes Some of the ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterotopagnosia
Heterotopagnosia is a neuro-psychological syndrome caused by brain damage in the left parietal lobe and corresponding to an acquired inability in pointing at and locating another person's body parts.Degos JD, Bachoud-Levi AC, Ergis AM, Petrissans JL & Cesaro P (1997) Selective inability to point to extrapersonal targets after left posterior parietal lesions: An Objectivization disorder?, Neurocase, 3:1, 31-39, DOI: 10.1080/13554799708404032Degos JD, Bachoud-Levi AC. Pointing and its object: towards the neuropsychology of objectivation. Rev Neurol (Paris). 1998 May;154(4):283-90. Its name comes from the Greek: "hetero" which means the other from a pair, "a" combined with "gnosis" means without knowledge, and "topos" means location. This clinical syndrome is distinct from autotopagnosia, another group of cognitive deficits associated with difficulties in locating body parts on own's one body. Allotopagnosia is another related disorder in which the patient cannot point at any external ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerstmann Syndrome
Gerstmann syndrome is a neuropsychological disorder that is characterized by a constellation of symptoms that suggests the presence of a lesion usually near the junction of the temporal and parietal lobes at or near the angular gyrus. Gerstmann syndrome is typically associated with damage to the inferior parietal lobule of the dominant hemisphere. It is classically considered a left-hemisphere disorder, although right-hemisphere damage has also been associated with components of the syndrome. It is named after Jewish Austrian-born American neurologist Josef Gerstmann. Symptoms Gerstmann syndrome is characterized by four primary symptoms, collectively referred to as a tetrad: # Dysgraphia/agraphia: deficiency in the ability to write # Dyscalculia/acalculia: difficulty in learning or comprehending mathematics # Finger agnosia: inability to distinguish the fingers on the hand # Left-right disorientation Causes This disorder is often associated with brain lesions in the domina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finger Agnosia
Finger agnosia, first defined in 1924 by Josef Gerstmann, is the loss in the ability to distinguish, name, or recognize the fingers—not only the patient's own fingers, but also the fingers of others, and drawings and other representations of fingers. It is one of a tetrad of symptoms in Gerstmann syndrome, although it is also possible for finger agnosia to exist on its own without any other disorders. Usually, lesions to the left angular gyrus and posterior parietal areas can lead to finger agnosia. Causes Lesions to the left angular gyrus are associated with finger agnosia, as well as the other symptoms of Gerstmann Syndrome, also known as Angular Gyrus Syndrome. In a study by Rusconi et al., repetitive transcranial magnetic stimulation was used in healthy individuals to simulate finger agnosia. Stimulation to the intraparietal sulcus, supramarginal gyrus, as well as the left and right angular gyrus and posterior parietal areas caused difficulties in naming, recognizing, and dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortical Deafness
Cortical deafness is a rare form of sensorineural hearing loss caused by damage to the primary auditory cortex. Cortical deafness is an auditory disorder where the patient is unable to hear sounds but has no apparent damage to the anatomy of the ear (see auditory system), which can be thought of as the combination of auditory verbal agnosia and auditory agnosia. Patients with cortical deafness cannot hear any sounds, that is, they are not aware of sounds including non-speech, voices, and speech sounds. Although patients appear and feel completely deaf, they can still exhibit some reflex responses such as turning their head towards a loud sound. Cause Cortical deafness is caused by bilateral cortical lesions in the primary auditory cortex located in the temporal lobes of the brain. The ascending auditory pathways are damaged, causing a loss of perception of sound. Inner ear functions, however, remains intact. Cortical deafness is most often caused by stroke, but can also result from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Agnosia
Cerebral achromatopsia is a type of color-blindness caused by damage to the cerebral cortex of the brain, rather than abnormalities in the cells of the eye's retina. It is often confused with congenital achromatopsia but underlying physiological deficits of the disorders are completely distinct. A similar, but distinct, deficit called color agnosia exists in which a person has intact color perception (as measured by a matching task) but has deficits in color recognition, such as knowing which color they are looking at. Signs and symptoms Patients with cerebral achromatopsia deny having any experience of color when asked and fail standard clinical assessments like the Farnsworth-Munsell 100-hue test (a test of color ordering with no naming requirements). Patients may often not notice their loss of color vision and merely describe the world they see as being "drab". Most describe seeing the world in "shades of gray". This observation notes a key difference between cerebral and cong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Achromatopsia
Cerebral achromatopsia is a type of color-blindness caused by damage to the cerebral cortex of the brain, rather than abnormalities in the cells of the eye's retina. It is often confused with congenital achromatopsia but underlying physiological deficits of the disorders are completely distinct. A similar, but distinct, deficit called color agnosia exists in which a person has intact color perception (as measured by a matching task) but has deficits in color recognition, such as knowing which color they are looking at. Signs and symptoms Patients with cerebral achromatopsia deny having any experience of color when asked and fail standard clinical assessments like the Farnsworth-Munsell 100-hue test (a test of color ordering with no naming requirements). Patients may often not notice their loss of color vision and merely describe the world they see as being "drab". Most describe seeing the world in "shades of gray". This observation notes a key difference between cerebral and cong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parietal Lobe
The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integrates sensory information among various modalities, including spatial sense and navigation (proprioception), the main sensory receptive area for the sense of touch in the somatosensory cortex which is just posterior to the central sulcus in the postcentral gyrus, and the dorsal stream of the visual system. The major sensory inputs from the skin (touch, temperature, and pain receptors), relay through the thalamus to the parietal lobe. Several areas of the parietal lobe are important in language processing. The somatosensory cortex can be illustrated as a distorted figure – the cortical homunculus (Latin: "little man") in which the body parts are rendered according to how much of the somatosensory cortex is devoted to them. The superior parietal lobule and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
