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
          
        
Alternate cues may be particularly useful to an individual with environmental agnosia or prosopagnosia. Alternate cues for an individual with environmental agnosia may include color cues or tactile markers to symbolize a new room or to remember an area by. Prosopagnosics may use alternate cues such as a scar on an individual's face or crooked teeth in order to recognize the individual. Hair color and length can be helpful cues as well.
Using verbal descriptions may be helpful for individuals with certain types of agnosia. Individuals such as prosopagnosics may find it useful to listen to a description of their friend or family member and recognize them based on this description more easily than through visual cues.
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.
There are few neuropsychological assessments that can definitively diagnose prosopagnosia. One commonly used test is the famous faces tests, where individuals are asked to recognize the faces of famous persons. However, this test is difficult to standardize. The Benton Facial Recognition Test (BFRT) is another test used by neuropsychologists to assess face recognition skills. Individuals are presented with a target face above six test faces and are asked to identify which test face matches the target face. The images are cropped to eliminate hair and clothes, as many people with prosopagnosia use hair and clothing cues to recognize faces. Both male and female faces are used during the test. For the first six items only one test face matches the target face; during the next seven items, three of the test faces match the target faces and the poses are different. The reliability of the BFRT was questioned when a study conducted by Duchaine and Nakayama showed that the average score for 11 self-reported prosopagnosics was within the normal range.
The test may be useful for identifying patients with apperceptive prosopagnosia, since this is mainly a matching test and they are unable to recognize both familiar and unfamiliar faces. They would be unable to pass the test. It would not be useful in diagnosing patients with associative prosopagnosia since they are able to match faces.
The Cambridge Face Memory Test (CFMT) was developed by Duchaine and Nakayama to better diagnose people with prosopagnosia. This test initially presents individuals with three images each of six different target faces. They are then presented with many three-image series, which contain one image of a target face and two distracters. Duchaine and Nakayama showed that the CFMT is more accurate and efficient than previous tests in diagnosing patients with prosopagnosia. Their study compared the two tests and 75% of patients were diagnosed by the CFMT, while only 25% of patients were diagnosed by the BFRT. However, similar to the BFRT, patients are being asked to essentially match unfamiliar faces, as they are seen only briefly at the start of the test. The test is not currently widely used and will need further testing before it can be considered reliable.
The 20-item Prosopagnosia Index (PI20) is a freely available and validated self-report questionnaire that is able to identify individuals with prosopagnosia. It has been validated against the famous faces test and Cambridge Face Memory Test, with evidence that PI20 scores are correlated with performance on these objective measures of face recognition. It can be downloaded from the Royal Society's Open Science website and on . Alternatively, the questionnaire can be completed online on the official website.
Individuals with conduction aphasia are able to express themselves fairly well, with some word finding and functional comprehension difficulty. Although people with aphasia may be able to express themselves fairly well, they tend to have issues repeating phrases, especially phrases that are long and complex. When asked to repeat something, the patient will be unable to do so without significant difficulty, repeatedly attempting to self-correct ("conduite d'approche"). When asked a question, however, patients can answer spontaneously and fluently.
Several standardized test batteries exist for diagnosing and classifying aphasias. These tests are capable of identifying conduction aphasia with relative accuracy. The Boston Diagnostic Aphasia Examination (BDAE) and the Western Aphasia Battery (WAB) are two commonly used test batteries for diagnosing conduction aphasia. These examinations involve a set of tests, which include asking patients to name pictures, read printed words, count aloud, and repeat words and non-words (such as "shwazel").
Cases with integrative agnosia appear to have medial ventral lesions in the extrastriate cortex. Those who have integrative agnosia are better able to identify inanimate than animate items, which indicates processes that lead to accurate perceptual organization of visual information can be impaired. This is attributed to the importance of perceptual updating of stored visual knowledge, which is particularly important for classes of stimuli that have many perceptual neighbors and/or stimuli for which perceptual features are central to their stored representations. Patients also show a tendency to process visual stimuli initially at a global rather than local level. Although the grouping of local elements into perceptual wholes can be impaired, patients can remain sensitive to holistic visual representations.
When determining whether a patient has form agnosia or integrative agnosia, an Efron shape test can be performed. A poor score on the Efron shape test will indicate form agnosia, as opposed to integrative agnosia. A good score on the Efron shape test, but a poor score on a figure-ground segmentation test and an overlapping figures test will indicate integrative agnosia. A patient with integrative agnosia will find it hard to group and segment shapes, especially if there are overlapping animate items or they can over segment objects with high internal detail. However, the patient should have and understand basic coding of shape.
Treatment for aphasias is generally individualized, focusing on specific language and communication improvements, and regular exercise with communication tasks. Regular therapy for conduction aphasics has been shown to result in steady improvement on the Western Aphasia Battery. However, conduction aphasia is a mild aphasia, and conduction aphasics score highly on the WAB at baseline.
Specialists, like ophthalmologists or audiologists, can test for perceptual abilities. Detailed testing is conducted, using specially formulated assessment materials, and referrals to neurological specialists is recommended to support a diagnosis via brain imaging or recording techniques. The separate stages of information processing in the object recognition model are often used to localize the processing level of the deficit.
Testing usually consists of object identification and perception tasks including:
- object-naming tasks
- object categorization or figure matching
- drawing or copying real objects or images or illustrations
- unusual views tests
- overlapping line drawings
- partially degraded or fragmented image identification
- face or feature analysis
- fine line judgment
- figure contour tracking
- visual object description
- object-function miming
- tactile ability tests (naming by touch)
- auditory presentation identification
Sensory modality testing allows practitioners to assess for generalized versus specific deficits, distinguishing visual agnosias from optic aphasia, which is a more generalized deficit in semantic knowledge for objects that spans multiple sensory modalities, indicating an impairment in the semantic representations themselves.
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.
The nature of the alleged mental representations that underlie the act of pointing to target body parts have been a controversial issue. Originally, it was diagnosed as the effects of general mental deterioration or of aphasia on the task of pointing to body parts on verbal command. However, contemporary neuropsychological therapy seeks to establish the independence of autotopagnosia from other disorders. With such a general definition, a patient that presents with a dysfunction of or failure in accessing one of four mental representation systems suffers from autotopagnosia. Through observational testing, the type of mental misrepresentation of the body can be deduced: whether "semantic", "visuospatial", "somatosensory", or "motor misrepresentations". Neuropsychological tests can provide a proper diagnosis in regards to the specificity of patient’s agnosic condition.
1) Test 1: Body Part Localization: Free vision and no vision conditions
2) Test 2: On-line positioning of body vis-à-vis objects
3) Test 3: Localization of objects on the body surface
4) Test 4: Body part semantic knowledge
5) Test 5: Matching body parts: Effect of viewing angle
Sign language therapy has been identified as one of the top five most common treatments for auditory verbal agnosia. This type of therapy is most useful because, unlike other treatment methods, it does not rely on fixing the damaged areas of the brain. This is particularly important with AVA cases because it has been so hard to identify the causes of the agnosia in the first place, much less treat those areas directly. Sign language therapy, then, allows the person to cope and work around the disability, much in the same way it helps deaf people. In the beginning of therapy, most will work on identifying key objects and establishing an initial core vocabulary of signs. After this, the patient graduates to expand the vocabulary to intangible items or items that are not in view or present. Later, the patient learns single signs and then sentences consisting of two or more signs. In different cases, the sentences are first written down and then the patient is asked to sign them and speak them simultaneously. Because different AVA patients vary in the level of speech or comprehension they have, sign language therapy learning order and techniques are very specific to the individual's needs.
1. SCAN is the most common tool for diagnosing APD, and it also standardized. It is composed for four subsets: discrimination of monaurally presented single words against background noise, acoustically degraded single words, dichotically presented single words, sentence stimuli. Different versions of the test are used depending on the age of the patient.
2. Random Gap Detection Test (RGDT) is also a standardized test. It assesses an individual’s gap detection threshold of tones and white noise. The exam includes stimuli at four different frequencies (500, 1000, 2000, and 4000 Hz) and white noise clicks of 50 ms duration. It is a useful test because it provides an index of auditory temporal resolution. In children, an overall gap detection threshold greater than 20 ms means they have failed.
3. Gaps in Noise Test (GIN) also measures temporal resolution by testing the patient's gap detection threshold in white noise.
4. Pitch Patterns Sequence Test (PPT) and Duration Patterns Sequence Test (DPT) measure auditory pattern identification. The PPS has s series of three tones presented at either of two pitches (high or low). Meanwhile, the DPS has a series of three tones that vary in duration rather than pitch (long or short). Patients are then asked to describe the pattern of pitches presented.
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.
A number of computer-based auditory training programs exist for children with generalized Auditory Processing Disorders (APD). In the visual system, it has been proven that adults with amblyopia can improve their visual acuity with targeted brain training programs (perceptual learning). A focused perceptual training protocol for children with amblyaudia called Auditory Rehabilitation for Interaural Asymmetry (ARIA) was developed in 2001 which has been found to improve dichotic listening performance in the non-dominant ear and enhance general listening skills. ARIA is now available in a number of clinical sites in the U.S., Canada, Australia and New Zealand. It is also undergoing clinical research trials involving electrophysiologic measures and activation patterns acquired through functional magnetic resonance imaging (fMRI) techniques to further establish its efficacy to remediate amblyaudia.
A clinical diagnosis of amblyaudia is made following dichotic listening testing as part of an auditory processing evaluation. Clinicians are advised to use newly developed dichotic listening tests that provide normative cut-off scores for the listener's dominant and non-dominant ears. These are the Randomized Dichotic Digits Test and the Dichotic Words Test. Older dichotic listening tests that provide normative information for the right and left ears can be used to supplement these two tests for support of the diagnosis (). If performance across two or more dichotic listening tests is normal in the dominant ear and significantly below normal in the non-dominant ear, a diagnosis of amblyaudia can be made. The diagnosis can also be made if performance in both ears is below normal but performance in the non-dominant ear is significantly poorer, thereby resulting in an abnormally large asymmetry between the two ears. Amblyaudia is emerging as a distinct subtype of auditory processing disorder (APD).
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.
Assessment will usually include an interview with the child’s caregiver, observation of the child in an unstructured setting, a hearing test, and standardized tests of language and nonverbal ability. There is a wide range of language assessments in English. Some are restricted for use by speech and language professionals (therapists or SALTs in the UK, speech-language pathologists, SLPs, in the US and Australia).
A commonly used test battery for diagnosis of SLI is the Clinical Evaluation of Language Fundamentals (CELF).
Assessments that can be completed by a parent or teacher can be useful to identify children who may require more in-depth evaluation.
The Grammar and Phonology Screening (GAPS) test is a quick (ten minute) simple and accurate screening test developed and standardized in the UK. It is suitable for children from 3;4 to 6;8 years;months and can be administered by professionals and non-professionals (including parents) alike, and has been demonstrated to be highly accurate (98% accuracy) in identifying impaired children who need specialist help vs non-impaired children. This makes it potentially a feasible test for widespread screening.
The Children’s Communication Checklist (CCC–2) is a parent questionnaire suitable for testing language skills in school-aged children.
Informal assessments, such as language samples, may also be used. This procedure is useful when the normative sample of a given test is inappropriate for a given child, for instance, if the child is bilingual and the sample was of monolingual children. It is also an ecologically valid measure of all aspects of language (e.g. semantics, syntax, pragmatics, etc.).
To complete a language sample, the SLP will spend about 15 minutes talking with the child. The sample may be of a conversation (Hadley, 1998), or narrative retell. In a narrative language sample, the SLP will tell the child a story using a wordless picture book (e.g. "Frog Where Are You?", Mayer, 1969), then ask the child to use the pictures and tell the story back.
Language samples are typically transcribed using computer software such as the Systematic Analysis of Language Software (SALT, Miller et al. 2012), and then analyzed. For example, the SLP might look for whether the child introduces characters to their story or jumps right in, whether the events follow a logical order, and whether the narrative includes a main idea or theme and supporting details.
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.
There are three primary distinctions of auditory agnosia that fall into two categories.
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.
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.
Broadly, visual agnosia is divided into apperceptive and associative visual agnosia.
Apperceptive agnosia is failure of object recognition even when the basic visual functions (acuity, color, motion) and other mental processing, such as language and intelligence, are normal. The brain must correctly integrate features such as edges, light intensity, and color from sensory information to form a complete percept of an object. If a failure occurs during this process, a percept of an object is not fully formed and thus it cannot be recognized. Tasks requiring copying, matching, or drawing simple figures can distinguish the individuals with apperceptive agnosia because they cannot perform such tasks.
Associative agnosia is an inability to identify objects even with apparent perception and knowledge of them. It involves a higher level of processing than apperceptive agnosia. Individuals with associative agnosia can copy or match simple figures, indicating that they can perceive objects correctly. They also display the knowledge of objects when tested with tactile or verbal information. However, when tested visually, they cannot name or describe common objects. This means that there is an impairment in associating the perception of objects with the stored knowledge of them.
Although visual agnosia can be general, there exist many variants that impair recognition of specific types. These variants of visual agnosia include prosopagnosia (inability to recognize faces), pure word blindness (inability to recognize words, often called "agnosic alexia" or "pure alexia"), agnosias for colors (inability to differentiate colors), agnosias for the environment (inability to recognize landmarks or difficult with spatial layout of an environment, i.e. topographagnosia) and simultanagosia (inability to sort out multiple objects in a visual scene).
APD is a difficult disorder to detect and diagnose. The subjective symptoms that lead to an evaluation for APD include an intermittent inability to process verbal information, leading the person to guess to fill in the processing gaps. There may also be disproportionate problems with decoding speech in noisy environments.
APD has been defined anatomically in terms of the integrity of the auditory areas of the nervous system. However, children with symptoms of APD typically have no evidence of neurological disease and the diagnosis is made on the basis of performance on behavioral auditory tests. Auditory processing is "what we do with what we hear", and in APD there is a mismatch between peripheral hearing ability (which is typically normal) and ability to interpret or discriminate sounds. Thus in those with no signs of neurological impairment, APD is diagnosed on the basis of auditory tests. There is, however, no consensus as to which tests should be used for diagnosis, as evidenced by the succession of task force reports that have appeared in recent years. The first of these occurred in 1996. This was followed by a conference organized by the American Academy of Audiology. Experts attempting to define diagnostic criteria have to grapple with the problem that a child may do poorly on an auditory test for reasons other than poor auditory perception: for instance, failure could be due to inattention, difficulty in coping with task demands, or limited language ability. In an attempt to rule out at least some of these factors, the American Academy of Audiology conference explicitly advocated that for APD to be diagnosed, the child must have a modality-specific problem, i.e. affecting auditory but not visual processing. However, an ASHA committee subsequently rejected modality-specificity as a defining characteristic of auditory processing disorders.
Topographical disorientation is usually diagnosed with the use of a comprehensive battery of neuropsychological tests combined with a variety of orientation tasks performed by the participants in both virtual and real surroundings. Performance on certain tests can identify underlying neurological disorders and verify the disorientation as a selective impairment. Brain imaging is used to determine regions of brain damage, if any. Navigational skills can be assessed by tests pertaining to memory, visual-perceptual abilities, object recognition, mental rotation, imagery abilities, and spatial abilities. More direct testing of navigation involves asking the patient to describe a route, read a map, draw a map, follow a route, or point out landmarks.