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
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.
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
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.
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.
In order to assess an individual for agnosia, it must be verified that the individual is not suffering from a loss of sensation, and that both their language abilities and intelligence are intact. In order for an individual to be diagnosed with agnosia, they must only be experiencing a sensory deficit in a single modality. To make a diagnosis, the distinction between apperceptive and associative agnosia must be made. This distinction can be made by having the individual complete copying and matching tasks. If the individual is suffering from a form of apperceptive agnosia they will not be able to match two stimuli that are identical in appearance. In contrast, if an individual is suffering from a form of associative agnosia, they will not be able to match different examples of a stimulus. For example, an individual who has been diagnosed with associative agnosia in the visual modality would not be able to match pictures of a laptop that is open with a laptop that is closed.
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.
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.
There are currently no quantitative methods for diagnosing simultanagnosia. To establish the presence of simultanagnosic symptoms, patients are asked to describe complex visual displays, such as the commonly used "Boston Cookie Theft" picture, which is a component of the Boston Diagnostic Aphasia Examination. In the picture, the sink in the kitchen is overflowing as a boy and a girl attempt to steal cookies from the cookie jar without their mother noticing.
Patients take a clearly piecemeal approach to interpreting the scene by reporting isolated items from the image. For instance, a patient may report seeing a "boy," "stool," and a "woman." However, when asked to interpret the overall meaning of the picture, the patient fails to comprehend the global whole. Another picture used to assess visual impairments of patients with simultanagnosia is the "Telegraph Boy" picture. Upon examination of higher nervous system functions, patients display no general intellectual impairments.
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.
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.
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.
Clinically, anosognosia is often assessed by giving patients an anosognosia questionnaire in order to assess their metacognitive knowledge of deficits. However, neither of the existing questionnaires applied in the clinics are designed thoroughly for evaluating the multidimensional nature of this clinical phenomenon; nor are the responses obtained via offline questionnaire capable of revealing the discrepancy of awareness observed from their online task performance. The discrepancy is noticed when patients showed no awareness of their deficits from the offline responses to the questionnaire but demonstrated reluctance or verbal circumlocution when asked to perform an online task. For example, patients with anosognosia for hemiplegia may find excuses not to perform a bimanual task even though they do not admit it is because of their paralyzed arms.
A similar situation can happen on patients with anosognosia for cognitive deficits after traumatic brain injury when monitoring their errors during the tasks regarding their memory and attention (online emergent awareness) and when predicting their performance right before the same tasks (online anticipatory awareness). It can also occur among patients with dementia and anosognosia for memory deficit when prompted with dementia-related words, showing possible pre-attentive processing and implicit knowledge of their memory problems. More interestingly, patients with anosognosia may overestimate their performance when asked in first-person formed questions but not from a third-person perspective when the questions referring to others.
When assessing the causes of anosognosia within stroke patients, CT scans have been used to assess where the greatest amount of damage is found within the various areas of the brain. Stroke patients with mild and severe levels of anosognosia (determined by response to an anosognosia questionnaire) have been linked to lesions within the temporoparietal and thalamic regions, when compared to those who experience moderate anosognosia, or none at all. In contrast, after a stroke, people with moderate anosognosia have a higher frequency of lesions involving the basal ganglia, compared to those with mild or severe anosognosia.
Ideational apraxia is a difficult disorder to diagnose. That is because the majority of individuals who have this disorder almost always have some other type of dysfunction such as agnosia or aphasia. The tests used to make an IA diagnosis can range from easy single object tasks to complex multiple object tasks. When being tested a patient may be asked to view twenty objects. They then have to demonstrate the use of each single object following three different ways of presenting the stimuli. The patient must then perform complex test where the examiner describes a task such as making coffee and the patient must show the sequential steps that makes a cup of coffee. The patients are then scored on how many errors are seen by the examiner. The errors of the patients in performing the MOT were scored according to a set of criteria partly derived from De Renzi and Lucchelli.
Two classes of errors are used to develop a diagnosis:
Class I: Sequence errors
- Action addition (AA) is a meaningful action step that is not necessary for accomplishing the goal of the MOT action (e.g., removing the filter of the orange squeezer in order to pour the liquid);
- Action anticipation (A) is an anticipation of an action that would normally be performed later in the action sequence (e.g., blowing the match out before using it);
- Step omission (SO) is an omission of a step of the multiple-actions sequence (e.g., inserting the filter in the coffee machine without pouring some water);
- Perseveration (P) is a repetition of an action step previously performed in the action sequence.
Class II: Conceptual errors
- Misuse (Mis) errors that can be differentiated into two further types:
1. (Mis1) the first type of misuse involves a well-performed action that is appropriate to an object different from the object target (e.g., hammering with a saw);
2. (Mis2) the second type involves an action that is appropriate at a superordinate level to the object at hand but is inappropriately specified at the subordinate level (e.g., cutting an orange with a knife as if it were butter).
- Mislocation (Misl) which can be further differentiated into two error subtypes:
1. (Misl1) the first type is an action that is appropriate to the object in hand but is performed in completely the wrong place (e.g., pouring some liquid from the bottle onto the table rather than into the glass);
2. (Misl2) the second type involves the correct general selection of the target object on which to operate with the source object or instrument in hand but with the exact location of the action being wrong (e.g., striking the match inside the matchbox).
- Tool omission (TO) is an omission in using an obligatory tool where the hand is used instead (e.g., opening a bottle without using a bottle opener);
- Pantomiming (Pant) is where the patient pantomime show the object should be used instead of using it;
- Perplexity (Perpl) Is a delay or hesitation in starting an action or subcomponents of an action;
- Toying(T) consists of a brief but repeated touching of an object or objects on the table.
As the examiner observes the patient for each task they mark off which errors were committed. From this criteria the examiner will be able to focus on severity of the dysfunction. It is important to express that the motor movement is not lost in patients with IA. Yet, at first glance their movements may appear to be awkward because they are unable to plan a sequence of movements with the given object.
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.
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.
Constructional disabilities are often tested by asking the patient to draw a 2D model or assemble an object. Some researchers feel that neuronal mechanisms involved in drawing and copying differ, thus they should be tested individually. Free drawing is a commonly used test in which the patient is asked to draw a named object. It can be an effective tool in measuring the patient's ability to maintain spatial relations, organize the drawing, and draw complete shapes. The complexity of the task should be noted as such tasks often require lexical-semantic abilities as well as imagery abilities.
Treatment consists of finding ways to bring the patient's attention toward the left, usually done incrementally, by going just a few degrees past midline, and progressing from there. Rehabilitation of neglect is often carried out by neuropsychologists, occupational therapist,
speech-language pathologists, neurologic music therapists, physical therapists, optometrists and orthoptists.
Forms of treatment that have been tested with variable reports of success include prismatic adaptation, where a prism lens is worn to pull the vision of the patient towards the left, constrained movement therapy where the "good" limb is constrained in a sling to encourage use of the contralesional limb. Eye-patching has similarly been used, placing a patch over the "good" eye. Pharmaceutical treatments have mostly focused on dopaminergic therapies such as bromocriptine, levodopa, and amphetamines, though these tests have had mixed results, helping in some cases and accentuating hemispatial neglect in others. Caloric vestibular stimulation (CVS) has been shown to bring about a brief remission in some cases. however this technique has been known to elicit unpleasant side-effects such as nystagmus, vertigo and vomiting.
A study done by Schindler and colleagues examined the use of neck muscle vibration on the contralesional posterior neck muscles to induce diversion of gaze from the subjective straight ahead. Subjects received 15 consecutive treatment sessions and were evaluated on different aspects of the neglect disorder including perception of midline, and scanning deficits. The study found that there is evidence that neck muscle stimulation may work, especially if combined with visual scanning techniques. The improvement was evident 2 months after the completion of treatment.
Other areas of emerging treatment options include the use of prisms, visual scanning training, mental imagery training, video feedback training, trunk rotation, galvanic vestibular stimulation (GVS), transcranial magnetic stimulation (TMS) and transcranial direct-current stimulation (tDCS). Of these emerging treatment options, the most studied intervention is prism adaptation and there is evidence of relatively long-term functional gains from comparatively short-term usage. However, all of these treatment interventions (particularly the stimulation techniques) are relatively new and randomised, controlled trial evidence is still limited. Further research is mandatory in this field of research in order to provide more support in evidence-based practice.
In a review article by Pierce & Buxbaum (2002), they concluded that the evidence for Hemispheric Activation Approaches, which focuses on moving the limb on the side of the neglect, has conflicting evidence in the literature. The authors note that a possible limitation in this approach is the requirement for the patients to actively move the neglected limb, which may not be possible for many patients. Constraint-Induced Therapy (CIT), appears to be an effective, long-term treatment for improving neglect in various studies. However, the use of CIT is limited to patients who have active control of wrist and hand extension. Prism Glasses, Hemispatial Glasses, and Eye-Patching have all appear to be effective in improving performance on neglect tests. Caloric Stimulation treatment appears to be effective in improving neglect; however, the effects are generally short-term. The review also suggests that Optokinetic Stimulation is effective in improving position sense, motor skills, body orientation, and perceptual neglect on a short-term basis. As with Caloric Stimulation treatment, long-term studies will be necessary to show its effectiveness. A few Trunk Rotation Therapy studies suggest its effectiveness in improving performance on neglect tests as well as the Functional Independence Measure (FIM). Some less studied treatment possibilities include treatments that target Dorsal Stream of visual processing, Mental Imagery Training, and Neck Vibration Therapy. Trunk rotation therapies aimed at improving postural disorders and balance deficits in patients with unilateral neglect, have demonstrated optimistic results in regaining voluntary trunk control when using specific postural rehabilitative devices. One such device is the Bon Saint Côme apparatus, which uses spatial exploratory tasks in combination with auditory and visual feedback mechanisms to develop trunk control. The Bon Saint Côme device has been shown to be effective with hemiplegic subjects due to the combination of trunk stability exercises, along with the cognitive requirements needed to perform the postural tasks.
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.
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.
The verbal fluency test is a widely and commonly used test to assess for frontal lobe dysfunction in patients.
- Procedure:
Participants are asked to generate words beginning with letters that had previously been introduced to them (e.g.: generate a word beginning with 'A' or 'R'). They are given three 1-min trials (one trial per letter). The goal is to say as many different words possible that begin with the given letter.
- Results:
The Verbal fluency test can assess for damage in the prefrontal lobes, which has been associated with patients suffering from source amnesia. Patients with frontal lobe disorder have trouble putting verbal items into a proper sequential order, monitor personal behaviors as well as a deficient judgment in recency. All of these behaviors are required for the proper recall of the source of a memory.
In regard to anosognosia for neurological patients, no long-term treatments exist. As with unilateral neglect, caloric reflex testing (squirting ice cold water into the left ear) is known to temporarily ameliorate unawareness of impairment. It is not entirely clear how this works, although it is thought that the unconscious shift of attention or focus caused by the intense stimulation of the vestibular system temporarily influences awareness. Most cases of anosognosia appear to simply disappear over time, while other cases can last indefinitely. Normally, long-term cases are treated with cognitive therapy to train patients to adjust for their inoperable limbs (though it is believed that these patients still are not "aware" of their disability). Another commonly used method is the use of feedback – comparing clients' self-predicted performance with their actual performance on a task in an attempt to improve insight.
Neurorehabilitation is difficult because, as anosognosia impairs the patient's desire to seek medical aid, it may also impair their ability to seek rehabilitation. A lack of awareness of the deficit makes cooperative, mindful work with a therapist difficult. In the acute phase, very little can be done to improve their awareness, but during this time, it is important for the therapist to build a therapeutic alliance with patients by entering their phenomenological field and reducing their frustration and confusion. Since severity changes over time, no single method of treatment or rehabilitation has emerged or will likely emerge.
In regard to psychiatric patients, empirical studies verify that, for individuals with severe mental illnesses, lack of awareness of illness is significantly associated with both medication non-compliance and re-hospitalization. Fifteen percent of individuals with severe mental illnesses who refuse to take medication voluntarily under any circumstances may require some form of coercion to remain compliant because of anosognosia. Coercive psychiatric treatment is a delicate and complex legal and ethical issue.
One study of voluntary and involuntary inpatients confirmed that committed patients require coercive treatment because they fail to recognize their need for care. The patients committed to the hospital had significantly lower measures of insight than the voluntary patients.
Anosognosia is also closely related to other cognitive dysfunctions that may impair the capacity of an individual to continuously participate in treatment. Other research has suggested that attitudes toward treatment can improve after involuntary treatment and that previously committed patients tend later to seek voluntary treatment.
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.
Motor imagery has been explored as a potential therapy for constructional apraxia patients. Motor imagery is a process by which a specific action is mimicked in the working memory without a corresponding motor output. Since constructional apraxia is a visuospatial problem not a motor problem, rehabilitation-treatment based on motor imagery has not proven to be an effective in patients with right hemisphere stroke or hemispatial neglect.