Agnosia - AbsoluteAstronomy.com

Agnosia 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

Acquired brain injury

An acquired brain injury is brain damage caused by events after birth, rather than as part of a genetic or congenital disorder such as fetal alcohol syndrome, perinatal illness or perinatal hypoxia. ABI can result in cognitive, physical, emotional, or behavioural impairments that lead to permanent...

or neurological illness, particularly after damage to the occipitotemporal border

Brodmann area 37

Brodmann area 37, or BA37, is part of the temporal cortex in the human brain.This area is known as occipitotemporal area 37 . It is a subdivision of the cytoarchitecturally defined temporal region of cerebral cortex...

, which is part of the ventral stream.

Types

Name	Description
Alexia Alexia (disorder) Alexia occurs when damage to the brain causes a patient to lose the ability to read...	Inability to recognize text.
Akinetopsia Akinetopsia Akinetopsia, also known as cerebral akinetopsia or motion blindness, is an extremely rare neuropsychological disorder in which a patient cannot perceive motion in their visual field, despite being able to see stationary objects without issue. For patients with akinetopsia, the world becomes devoid...	The loss of motion perception.
Alexithymia Alexithymia Alexithymia from the Ancient Greek words λέξις and θυμός modified by an alpha-privative—literally "without words for emotions"—is a term coined by psychotherapist Peter Sifneos in 1973 to describe a state of deficiency in understanding, processing, or describing...	>- \| Amusia Amusia Amusia is a musical disorder that appears mainly as a defect in processing pitch, but it also encompasses musical memory and recognition. Two main classifications of amusia exist: acquired amusia, which occurs as a result of brain damage, and congenital amusia, which results from a music processing... or Receptive amusia	>- \| Anosognosia Anosognosia Anosognosia /æˌnɒsɒgˈnəʊsɪə/ is a condition in which a person who suffers disability seems unaware of the existence of his or her disability. Unlike denial, which is a defense mechanism, anosognosia is rooted in physiology...	>- \| Apperceptive agnosia Apperceptive agnosia Apperceptive Agnosia is the visual disorder that renders a person unable to recognize objects. It is also known as visual space agnosia. Distinction between shapes is difficult, although other aspects of vision, such as ability to see detail and colour, remain intact. Recognition of, copying and...	>- \| Apraxia Apraxia Apraxia is a disorder caused by damage to specific areas of the cerebrum. Apraxia is characterized by loss of the ability to execute or carry out learned purposeful movements, despite having the desire and the physical ability to perform the movements...	>- \| Associative agnosia Associative agnosia People with associative agnosia fail in assigning meaning to an object, animal or building that they can see clearly. Most cases have injury to the occipital and temporal lobes and the critical site of injury appears to be in the left occipital-temporal region, often with involvement of the...	>- \| Auditory agnosia Auditory agnosia Auditory agnosia is a form of agnosia that manifests primarily in the inability to recognize or differentiate between sounds. It is not a defect of the ear, but a neurological inability of the brain to process what the sound means. Persons with auditory agnosia can physically hear the sounds and...	>- \| Autotopagnosia Autotopagnosia From the Greek a and gnosis, meaning “without knowledge”, and topos, meaning "place", autotopagnosia virtually translates to the “lack of knowledge about one’s own space,” and is clinically described as such.Autotopagnosia is a form of agnosia, characterized by an inability to localize and orient...	lesion Lesion A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :... in the parietal part Parietal lobe The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the... of the posterior thalmic radiations. >- \| Color agnosia Color agnosia Color agnosia , is a medical or psychological condition that prevents a person from correctly associating hue names with common objects. The sufferer retains the ability of distinguishing hues...	>- \| Cortical deafness	>- \| Finger agnosia	parietal lobe Parietal lobe The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the... , and is a component of Gerstmann syndrome Gerstmann syndrome Gerstmann syndrome is a neurological disorder that is characterized by a constellation of symptoms that suggests the presence of a lesion in a particular area of the brain... . >- \| Form agnosia	>- \| Integrative agnosia Integrative agnosia Integrative agnosia, as first defined by Riddoch and Humphreys , is the disability to recognize objects due to the inability to group and integrate the component parts of the object into a coherent whole...	>- \| Mirror agnosia	Hemispatial neglect Hemispatial neglect Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect, unilateral visual inattention, hemi-inattention or neglect syndrome is a neuropsychological condition in which, after damage to one hemisphere of the brain, a deficit in attention to and awareness of... . Patients with Hemispatial neglect Hemispatial neglect Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect, unilateral visual inattention, hemi-inattention or neglect syndrome is a neuropsychological condition in which, after damage to one hemisphere of the brain, a deficit in attention to and awareness of... were placed so that an object was in their neglected visual field but a mirror reflecting that object was visible in their non-neglected field. Patients could not acknowledge the existence of objects in the neglected field and so attempted to reach into the mirror to grasp the object. >- \| Pain agnosia	Analgesia, this is the difficulty perceiving and processing pain; thought to underpin some forms of self injury. >- \| Phonagnosia	>- \| Prosopagnosia Prosopagnosia Prosopagnosia is a disorder of face perception where the ability to recognize faces is impaired, while the ability to recognize other objects may be relatively intact...	faceblindness and facial agnosia: Patients cannot consciously recognize familiar faces, sometimes even including their own. This is often misperceived as an inability to remember names. >- \| Semantic agnosia	>- \| Simultanagnosia Simultanagnosia Simultanagnosia is a rare neurological disorder characterized by the inability of an individual to perceive more than a single object at a time. It is one of three major components of Bálint’s syndrome, an uncommon and incompletely understood variety of severe neuropsychological impairments...	visual field Visual field The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments", while 'field of view' "refers to the physical... , but only one at a time. They cannot make out the scene they belong to or make out a whole image out of the details. They literally "cannot see the forest for the trees." Simultanagnosia is a common symptom of Balint's syndrome Balint's syndrome Bálint's syndrome is an uncommon and incompletely understood triad of severe neuropsychological impairments: inability to perceive the visual field as a whole , difficulty in fixating the eyes , and inability to move the hand to a specific object by using vision... . >- \| Social emotional agnosia	>- \| Astereognosis Astereognosis Astereognosis is the inability to identify an object by touch without visual input. It is a form of tactile agnosia in which an individual is unable to identify objects by handling them, despite intact sensation. With the absence of vision , an individual with astereognosis is unable to identify...	Somatosensory agnosia is connected to tactile sense - that is, touch. Patient finds it difficult to recognize objects by touch based on its texture, size and weight. However, they may be able to describe it verbally or recognize same kind of objects from pictures or draw pictures of them. Thought to be connected to lesions or damage in somatosensory cortex. >- \| Tactile agnosia	>- \| Time agnosia	>- \| Topographical agnosia	>- \| Verbal auditory agnosia	>- \| Visual agnosia Visual agnosia Visual agnosia is the inability of the brain to make sense of or make use of some part of otherwise normal visual stimulus and is typified by the inability to recognize familiar objects or faces...	lesion Lesion A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :... s of the left occipital lobe Occipital lobe The occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1... and temporal lobes. Many types of visual agnosia involve the inability to recognize objects. >- \| Visual verbal agnosia	Difficulty comprehending the meaning of written words. The capacity to read is usually intact but comprehension is impaired.

Causes

Agnosia can result from stroke

Stroke

A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

s, dementia

Dementia

Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

, or other neurological disorder

Neurological disorder

A neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...

s. It may also be trauma-induced by a head injury, brain infection, or hereditary. Some forms of agnosia have been found to be genetic. A study in 2011 linked Phonagnosia to Dyslexia

Dyslexia

Dyslexia is a very broad term defining a learning disability that impairs a person's fluency or comprehension accuracy in being able to read, and which can manifest itself as a difficulty with phonological awareness, phonological decoding, orthographic coding, auditory short-term memory, or rapid...

.

Patients who experience dramatic recovery from blindness experience significant to total Agnosia.

Treatment

For all practical purposes, there is no direct cure. Patients may improve if information is presented in other modalities than the damaged one. Different types of therapies can help to reverse the effects of Agnosia. In some cases, occupational therapy

Occupational therapy

Occupational therapy is a discipline that aims to promote health by enabling people to perform meaningful and purposeful activities. Occupational therapists work with individuals who suffer from a mentally, physically, developmentally, and/or emotionally disabling condition by utilizing treatments...

or speech therapy can improve agnosia, depending on its etiology

Etiology

Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

External links

Types and brain areas
Total Recall: Memory Requires More than the Sum of Its Parts |accessdate=2007-06-05|publisher=Scientific American
Scientific American
Scientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Name	Description
Alexia Alexia (disorder) Alexia occurs when damage to the brain causes a patient to lose the ability to read...	Inability to recognize text.
Akinetopsia Akinetopsia Akinetopsia, also known as cerebral akinetopsia or motion blindness, is an extremely rare neuropsychological disorder in which a patient cannot perceive motion in their visual field, despite being able to see stationary objects without issue. For patients with akinetopsia, the world becomes devoid...	The loss of motion perception.
Alexithymia Alexithymia Alexithymia from the Ancient Greek words λέξις and θυμός modified by an alpha-privative—literally "without words for emotions"—is a term coined by psychotherapist Peter Sifneos in 1973 to describe a state of deficiency in understanding, processing, or describing...	>- \| Amusia Amusia Amusia is a musical disorder that appears mainly as a defect in processing pitch, but it also encompasses musical memory and recognition. Two main classifications of amusia exist: acquired amusia, which occurs as a result of brain damage, and congenital amusia, which results from a music processing... or Receptive amusia	>- \| Anosognosia Anosognosia Anosognosia /æˌnɒsɒgˈnəʊsɪə/ is a condition in which a person who suffers disability seems unaware of the existence of his or her disability. Unlike denial, which is a defense mechanism, anosognosia is rooted in physiology...	>- \| Apperceptive agnosia Apperceptive agnosia Apperceptive Agnosia is the visual disorder that renders a person unable to recognize objects. It is also known as visual space agnosia. Distinction between shapes is difficult, although other aspects of vision, such as ability to see detail and colour, remain intact. Recognition of, copying and...	>- \| Apraxia Apraxia Apraxia is a disorder caused by damage to specific areas of the cerebrum. Apraxia is characterized by loss of the ability to execute or carry out learned purposeful movements, despite having the desire and the physical ability to perform the movements...	>- \| Associative agnosia Associative agnosia People with associative agnosia fail in assigning meaning to an object, animal or building that they can see clearly. Most cases have injury to the occipital and temporal lobes and the critical site of injury appears to be in the left occipital-temporal region, often with involvement of the...	>- \| Auditory agnosia Auditory agnosia Auditory agnosia is a form of agnosia that manifests primarily in the inability to recognize or differentiate between sounds. It is not a defect of the ear, but a neurological inability of the brain to process what the sound means. Persons with auditory agnosia can physically hear the sounds and...	>- \| Autotopagnosia Autotopagnosia From the Greek a and gnosis, meaning “without knowledge”, and topos, meaning "place", autotopagnosia virtually translates to the “lack of knowledge about one’s own space,” and is clinically described as such.Autotopagnosia is a form of agnosia, characterized by an inability to localize and orient...	lesion Lesion A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :... in the parietal part Parietal lobe The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the... of the posterior thalmic radiations. >- \| Color agnosia Color agnosia Color agnosia , is a medical or psychological condition that prevents a person from correctly associating hue names with common objects. The sufferer retains the ability of distinguishing hues...	>- \| Cortical deafness	>- \| Finger agnosia	parietal lobe Parietal lobe The parietal lobe is a part of the Brain positioned above the occipital lobe and behind the frontal lobe.The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the... , and is a component of Gerstmann syndrome Gerstmann syndrome Gerstmann syndrome is a neurological disorder that is characterized by a constellation of symptoms that suggests the presence of a lesion in a particular area of the brain... . >- \| Form agnosia	>- \| Integrative agnosia Integrative agnosia Integrative agnosia, as first defined by Riddoch and Humphreys , is the disability to recognize objects due to the inability to group and integrate the component parts of the object into a coherent whole...	>- \| Mirror agnosia	Hemispatial neglect Hemispatial neglect Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect, unilateral visual inattention, hemi-inattention or neglect syndrome is a neuropsychological condition in which, after damage to one hemisphere of the brain, a deficit in attention to and awareness of... . Patients with Hemispatial neglect Hemispatial neglect Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect, unilateral visual inattention, hemi-inattention or neglect syndrome is a neuropsychological condition in which, after damage to one hemisphere of the brain, a deficit in attention to and awareness of... were placed so that an object was in their neglected visual field but a mirror reflecting that object was visible in their non-neglected field. Patients could not acknowledge the existence of objects in the neglected field and so attempted to reach into the mirror to grasp the object. >- \| Pain agnosia	Analgesia, this is the difficulty perceiving and processing pain; thought to underpin some forms of self injury. >- \| Phonagnosia	>- \| Prosopagnosia Prosopagnosia Prosopagnosia is a disorder of face perception where the ability to recognize faces is impaired, while the ability to recognize other objects may be relatively intact...	faceblindness and facial agnosia: Patients cannot consciously recognize familiar faces, sometimes even including their own. This is often misperceived as an inability to remember names. >- \| Semantic agnosia	>- \| Simultanagnosia Simultanagnosia Simultanagnosia is a rare neurological disorder characterized by the inability of an individual to perceive more than a single object at a time. It is one of three major components of Bálint’s syndrome, an uncommon and incompletely understood variety of severe neuropsychological impairments...	visual field Visual field The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments", while 'field of view' "refers to the physical... , but only one at a time. They cannot make out the scene they belong to or make out a whole image out of the details. They literally "cannot see the forest for the trees." Simultanagnosia is a common symptom of Balint's syndrome Balint's syndrome Bálint's syndrome is an uncommon and incompletely understood triad of severe neuropsychological impairments: inability to perceive the visual field as a whole , difficulty in fixating the eyes , and inability to move the hand to a specific object by using vision... . >- \| Social emotional agnosia	>- \| Astereognosis Astereognosis Astereognosis is the inability to identify an object by touch without visual input. It is a form of tactile agnosia in which an individual is unable to identify objects by handling them, despite intact sensation. With the absence of vision , an individual with astereognosis is unable to identify...	Somatosensory agnosia is connected to tactile sense - that is, touch. Patient finds it difficult to recognize objects by touch based on its texture, size and weight. However, they may be able to describe it verbally or recognize same kind of objects from pictures or draw pictures of them. Thought to be connected to lesions or damage in somatosensory cortex. >- \| Tactile agnosia	>- \| Time agnosia	>- \| Topographical agnosia	>- \| Verbal auditory agnosia	>- \| Visual agnosia Visual agnosia Visual agnosia is the inability of the brain to make sense of or make use of some part of otherwise normal visual stimulus and is typified by the inability to recognize familiar objects or faces...	lesion Lesion A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :... s of the left occipital lobe Occipital lobe The occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1... and temporal lobes. Many types of visual agnosia involve the inability to recognize objects. >- \| Visual verbal agnosia	Difficulty comprehending the meaning of written words. The capacity to read is usually intact but comprehension is impaired.