Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
There are clinical trials being done to further research for treatments. At the National Institute of Neurological Disorders and Stroke (NINDS) they support research for rare diseases like agnosia. Some organizations that are recruiting for trials are using clincaltrials.gov and give status updates on the trials.
These strategies elicit the use of an unaffected modality. For example, visual agnosics can use tactile information in replacement of visual information. Alternatively, an individual with prosopagnosia can use auditory information in order to replace visual information. For example, an individual with prosopagnosia can wait for someone to speak, and will usually recognize the individual from their speech.
The affected individual may not realize that they have a visual problem and may complain of becoming "clumsy" or "muddled" when performing familiar tasks such as setting the table or simple DIY.
Anosognosia, a lack of awareness of the deficit, is common and can cause therapeutic resistance. In some agnosias, such as prosopagnosia, awareness of the deficit is often present; however shame and embarrassment regarding the symptoms can be a barrier in admission of a deficiency. Because agnosias result from brain lesions, no direct treatment for them currently exists, and intervention is aimed at utilization of coping strategies by patients and those around them. Sensory compensation can also develop after one modality is impaired in agnostics
General principles of treatment:
- restitution
- repetitive training of impaired ability
- development of compensatory strategies utilizing retained cognitive functions
Partial remediation is more likely in cases with traumatic/vascular lesions, where more focal damage occurs, than in cases where the deficit arises out of anoxic brain damage, which typically results in more diffuse damage and multiple cognitive impairments. However, even with forms of compensation, some afflicted individuals may no longer be able to fulfill the requirements of their occupation or perform common tasks, such as, eating or navigating. Agnostics are likely to become more dependent on others and to experience significant changes to their lifestyle, which can lead to depression or adjustment disorders.
Management strategies for acquired prosopagnosia, such as a person who has difficulty recognizing people's faces after a stroke, generally have a low rate of success. Acquired prosopagnosia sometimes spontaneously resolves on its own.
Associative visual agnosia is a form of visual agnosia. It is an impairment in recognition or assigning meaning to a stimulus that is accurately perceived and not associated with a generalized deficit in intelligence, memory, language or attention. The disorder appears to be very uncommon in a "pure" or uncomplicated form and is usually accompanied by other complex neuropsychological problems due to the nature of the etiology. Afflicted individuals can accurately distinguish the object, as demonstrated by the ability to draw a picture of it or categorize accurately, yet they are unable to identify the object, its features or its functions.
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 low 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. 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), they have apperceptive agnosia. If a person correctly perceives the forms and has knowledge of the objects, but cannot identify the objects, they have associative agnosia.
As autotopagnosia arises from neurological and irreversible damage, options regarding symptom reversal or control are limited. As of April 2010, there are no known specific treatments for autotopagnosia.
No medications or pharmaceutical remedies have been approved by the U.S. Food and Drug Administration to treat or cure autotopagnosia. There have been cases in which extensive rehabilitation has been beneficial following restitution, repetitive training to correct the impaired function, and compensation of other skills to make up for the deficit. Rehabilitation is not a definitive treatment and only shows signs of slight improvement in a small percentage of autotopagnosia patients. The condition of the disease can be monitored with continued neurological examination and using a CT scan to note the progression of the parietal lesion.
One treatment thought to be effective is the repeated exposure to a particular face or object, where impaired perception may be reorganized in memory, leading to improvement on tests of imagery relative to tests of perception. The key factor for this type of treatment to be successful is a regular and consistent exposure, which will lead to improvements in the long run. Results may not be seen right away, but are eventually possible.
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.
Treating auditory verbal agnosia with intravenous immunoglobulin (IVIG) is controversial because of its inconsistency as a treatment method. Although IVIG is normally used to treat immune diseases, some individuals with auditory verbal agnosia have responded positively to the use of IVIG. Additionally, patients are more likely to relapse when treated with IVIG than other pharmacological treatments. IVIG is, thus, a controversial treatment as its efficacy in treating auditory verbal agnosia is dependent upon each individual and varies from case to case.
Apperceptive agnosia is a failure in recognition that is due to a failure of perception. In contrast, associative agnosia is a type of agnosia where perception occurs but recognition still does not occur. When referring to apperceptive agnosia, visual and object agnosia are most commonly discussed; This occurs because apperceptive agnosia is most likely to present visual impairments. However, in addition to visual apperceptive agnosia there are also cases of apperceptive agnosia in other sensory areas.
Agraphia cannot be directly treated, but individuals can be rehabilitated to regain some of their previous writing abilities.
For the management of phonological agraphia, individuals are trained to memorize key words, such as a familiar name or object, that can then help them form the grapheme for that phoneme. Management of allographic agraphia can be as simple as having alphabet cards so the individual can write legibly by copying the correct letter shapes. There are few rehabilitation methods for apraxic agraphia; if the individual has considerably better hand control and movement with typing than they do with handwriting, then they can use technological devices. Texting and typing do not require the same technical movements that handwriting does; for these technological methods, only spatial location of the fingers to type is required. If copying skills are preserved in an individual with apraxic agraphia, repeated copying may help shift from the highly intentional and monitored hand movements indicative of apraxic agraphia to a more automated control.
Micrographia is a condition that can occur with the development of other disorders, such as Parkinson's disease, and is when handwriting becomes illegible because of small writing. For some individuals, a simple command to write bigger eliminates the issue.
- Anagram and Copy Treatment (ACT) uses the arrangement of component letters of target words and then repeated copying of the target word. This is similar to the CART; the main difference is that the target words for ACT are specific to the individual. Target words that are important in the life of the individual are emphasized because people with deep or global agraphias do not typically have the same memory for the words as other people with agraphia may. Writing can be even more important to these people as it can cue spoken language. ACT helps in this by facilitating the relearning of a set of personally relevant written words for use in communication.
- Copy and Recall Treatment (CART) method helps to reestablish the ability to spell specific words that are learned through repeated copying and recall of target words. CART is more likely to be successful in treating lexical agraphia when a few words are trained to mastery than when a large group of unrelated words is trained. Words chosen can be individualized to the patient, which makes treatment more personalized.
- Graphemic buffer uses the training of specific words to improve spelling. Cueing hierarchies and copy and recall method of specific words are used, to work the words into the short-term memory loop, or graphemic buffer. The segmentation of longer words into shorter syllables helps bring words into short-term memory.
- Problem solving approach is used as a self-correcting method for phonological errors. The individual sounds out the word and attempts to spell it, typically using an electronic dictionary-type device that indicates correct spelling. This method takes advantage of the preserved sound-to-letter correspondences when they are intact. This approach may improve access to spelling memory, strengthen orthographic representations, or both.
In incidents where tumors and their pressure effects are the cause of pure word deafness, removal of the tumor has been shown to allow for the return of most auditory verbal comprehension.
Simultanagnosia (or simultagnosia) is a rare neurological disorder characterized by the inability of an individual to perceive more than a single object at a time. This type of visual attention problem is one of three major components (the others being optic ataxia and optic apraxia) of Bálint's syndrome, an uncommon and incompletely understood variety of severe neuropsychological impairments involving space representation (visuospatial processing). The term "simultanagnosia" was first coined in 1924 by Wolpert to describe a condition where the affected individual could see individual details of a complex scene but failed to grasp the overall meaning of the image.
Simultanagnosia can be divided into two different categories: dorsal and ventral. Ventral occipito-temporal lesions cause a mild form of the disorder, while dorsal occipito-parietal lesions cause a more severe form of the disorder.
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 a neurological inability of the brain to process sound meaning. It is a disruption of the "what" pathway in the brain. 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. Auditory agnosia is caused by damage to the secondary and tertiary auditory cortex of the temporal lobe of the brain.
As autotopagnosia is not a life-threatening condition it is not on the forefront of medical research. Rather, more research is conducted regarding treatments and therapies to alleviate the lesions and traumas that can cause autotopagnosia. Of all the agnosias, visual agnosia is the most common subject of investigation because it is easiest to assess and has the most promise for potential treatments. Most autotopagnosia studies are centered on a few test subjects as part of a group of unaffected or “controlled” participants, or a simple case study. Case studies surrounding a single patient are most common due to the vague nature of the disease.
"Developmental prosopagnosia" (DP), also called "Congenital prosopagnosia" (CP), is a face-recognition deficit that is lifelong, manifesting in early childhood, and that cannot be attributed to acquired brain damage. A number of studies have found functional deficits in DP both on the basis of EEG measures and fMRI. It has been suggested that a genetic factor is responsible for the condition. The term "hereditary prosopagnosia" was introduced if DP affected more than one family member, essentially accenting the possible genetic contribution of this condition. To examine this possible genetic factor, 689 randomly selected students were administered a survey in which seventeen developmental prosopagnosics were quantifiably identified. Family members of fourteen of the DP individuals were interviewed to determine prosopagnosia-like characteristics, and in all fourteen families, at least one other affected family member was found.
In 2005, a study led by Ingo Kennerknecht showed support for the proposed congenital disorder form of prosopagnosia. This study provides epidemiological evidence that congenital prosopagnosia is a frequently occurring cognitive disorder that often runs in families. The analysis of pedigree trees formed within the study also indicates that the segregation pattern of hereditary prosopagnosia (HPA) is fully compatible with autosomal dominant inheritance. This mode of inheritance explains why HPA is so common among certain families (Kennerknecht et al. 2006).
There are many developmental disorders associated with an increased likelihood that the person will have difficulties in face perception, of which the person may or may not be aware. The mechanism by which these perceptual deficits take place is largely unknown. A partial list of some disorders that often have prosopagnosiac components would include nonverbal learning disorder, Alzheimer's disease, and autism in general. However, these types of disorders are very complicated, so arbitrary assumptions should be avoided.
In 2012, it was shown that developmental prosopagnosia cases show poor integration of low and high spatial frequency information.
Topographical disorientation, also known as topographical agnosia and topographagnosia, is the inability to orient oneself in one's surroundings as a result of focal brain damage. This disability may result from the inability to make use of selective spatial information (e.g., environmental landmarks) or to orient by means of specific cognitive strategies such as the ability to form a mental representation of the environment, also known as a cognitive map. It may be part of a syndrome known as visuospatial dysgnosia.
Visuospatial dysgnosia is a loss of the sense of "whereness" in the relation of oneself to one's environment and in the relation of objects to each other. Visuospatial dysgnosia is often linked with topographical disorientation.
There are three primary distinctions of auditory agnosia that fall into two categories.
Patients with simultanagnosia, a component of Bálint's syndrome, have a restricted spatial window of visual attention and cannot see more than one object at a time in a scene that contains more than one object. For instance, if presented with an image of a table containing both food and various utensils, a patient will report seeing only one item, such as a spoon. If the patient's attention is redirected to another object in the scene, such as a glass, the patient will report that they see the glass but no longer see the spoon. As a result of this impairment, simultanagnosic patients often fail to comprehend the overall meaning of a scene.
In addition, patients note that one stationary object may spontaneously disappear from view as they become aware of another object in the scene.
Simultanagnosic patients often exhibit a phenomenon known as "local capture" where they only identify the local elements of stimuli containing local and global features. However, recent studies have demonstrated that implicit processing of the global structure can occur. With the appropriate stimulus conditions, explicit processing of the global form may occur. For example, a study performed with Navon hierarchical letters, which are large letters composed of smaller ones, revealed that the use of smaller and denser Navon letters biased the patient towards global processing.
While most cases of visual agnosia are seen in older adults who have experienced extensive brain damage, there are also cases of young children with less brain damage during developmental years acquiring the symptoms. Commonly, visual agnosia presents as an inability to recognize an object in the absence of other explanations, such as blindness or partial blindness, anomia, memory loss, etc.. Other common manifestations of visual agnosia that are generally tested for include difficulty identifying objects that look similar in shape, difficulty with identifying line drawings of objects, and recognizing objects that are shown from less common views, such as a horse from a top-down view.
Within any given patient, a variety of symptoms can occur, and the impairment of ability is not only binary but can range in severity. For example, Patient SM is a prosopagnosic with a unilateral lesion to left extrastriate cortex due to an accident in his twenties who displays behavior similar to congenital prosopagnosia. Although he can recognize facial features and emotions – indeed he sometimes uses a standout feature to recognize a face – face recognition is almost impossible purely from visual stimuli, even for faces of friends, family, and himself. The disorder also affects his memory of faces, both in storing new memories of faces and recalling stored memories.
Nevertheless, it is important to note the reach of symptoms to other domains. SM’s object recognition is similarly impaired though not entirely; when given line drawings to identify, he was able to give names of objects with properties similar to the drawing, implying that he is able to see the features of the drawing. Similarly, copying a line drawing of a beach scene led to a simplified version of the drawing, though the main features were accounted for. For recognition of places, he is still impaired but familiar places are remembered and new places can be stored into memory.
Treatment for topographical disorientation has been achieved through a case by case basis. Prognosis is largely dependent on the organic cause. Neuropsychological assessment followed by an assessment of unaffected cognitive abilities can be employed in therapy. Treatment for recovering navigational skills require strengthening unaffected navigational strategies to bypass defective ones.
Inconspicuous akinetopsia can be triggered by high doses of certain antidepressants with vision returning to normal once the dosage is reduced.
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.
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 Lancker and Cantor in 1982. The subjects in this study were asked to identify which of four names or faces matched a specific famous voice. The subjects could not complete the task. Since then, there have been a couple studies done on patients with phonagnosia. The clinical and radiologic findings with computerized tomographic scans cat scan in these cases suggest that recognition of familiar voices is impaired by damage to the inferior and parietal regions of the right hemisphere while voice discrimination is impaired by temporal lobe damage of either hemisphere. These studies have also shown evidence for a double dissociation between voice recognition and voice discrimination. Some patients will perform normally on the discrimination tasks but poorly on the recognition tasks; whereas the other patients will perform normally on the recognition tasks but poorly on the discrimination tasks. Patients did not perform poorly on both tasks.
Associative phonagnosia is a form of phonagnosia that develops with dementia or other focal neurodegenerative disorders. Some research has led to questions of other impairments in phonagnosics. Recently, studies have shown that phonagnosics also have trouble in recognizing the sounds of familiar instruments. As it is with voices, they also show deficiency in distinguishing between sounds from different instruments. Although the disability is shown, phonagnosics are much less affected in this area of sound discrimination. In distinguishing voices, it is a complete agnosia, but this is not the case for musical instrument sounds, as they can correctly identify some of them. Controversy arises in that not all phonagnosics exhibit these symptoms, and so not all researchers agree that it should be attributed to the damage suffered that causes phonagnosia. Much debate has arisen over the fact that it seems that separate areas of the brain are utilized to handle information from language and music. This has led some researchers to skeptically consider this impairment as a clear symptom of the disorder. Again, more research is needed to create a clearer conclusion.
An interesting attribute that phonagnosics possess is that they can correctly detect emotions in voices when someone talks to them. They can also correctly match an emotion with a facial expression. Although surprising, this finding is sensible because it is known and well agreed upon that the limbic system, involved in expressing emotions and detecting emotions of others, is a separate system within the brain. The limbic system is made up of several brain structures including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex and fornix.
Presently, there is no therapy or treatment for phonagnosia. Clearly, more research is needed to accomplish the feat of developing treatment for the disorder. The lack of treatment stems from the lack of knowledge about the disorder. Increased research will reveal vital information needed to formulate effective treatments and therapies.