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
Treatment for confabulation is somewhat dependent on the cause or source, if identifiable. For example, treatment of Wernicke–Korsakoff syndrome involves large doses of vitamin B in order to reverse the thiamine deficiency. If there is no known physiological cause, more general cognitive techniques may be used to treat confabulation. A case study published in 2000 showed that Self-Monitoring Training (SMT) reduced delusional confabulations. Furthermore, improvements were maintained at a three-month follow-up and were found to generalize to everyday settings. Although this treatment seems promising, more rigorous research is necessary to determine the efficacy of SMT in the general confabulation population.
Because psychogenic amnesia is defined by its lack of physical damage to the brain, treatment by physical methods is difficult. Nonetheless, distinguishing between organic and dissociative memory loss has been described as an essential first-step in effective treatments. Treatments in the past have attempted to alleve psychogenic amnesia by treating the mind itself, as guided by theories which range from notions such as 'betrayal theory' to account for memory loss attributed to protracted abuse by caregivers to the amnesia as a form of self-punishment in a Freudian sense, with the obliteration of personal identity as an alternative to suicide.
Treatment attempts often have revolved around trying to discover what traumatic event had caused the amnesia, and drugs such as intravenously administered barbiturates (often thought of as 'truth serum') were popular as treatment for psychogenic amnesia during World War II; benzodiazepines may have been substituted later. 'Truth serum' drugs were thought to work by making a painful memory more tolerable when expressed through relieving the strength of an emotion attached to a memory. Under the influence of these 'truth' drugs the patient would more readily talk about what had occurred to them. However, information elicited from patients under the influence of drugs such as barbiturates would be a mixture of truth and fantasy, and was thus not regarded as scientific in gathering accurate evidence for past events. Often treatment was aimed at treating the patient as a whole, and probably varied in practice in different places. Hypnosis was also popular as a means for gaining information from people about their past experiences, but like 'truth' drugs really only served to lower the threshold of suggestibility so that the patient would speak easily but not necessarily truthfully. If no motive for the amnesia was immediately apparent, deeper motives were usually sought by questioning the patient more intensely, often in conjunction with hypnosis and 'truth' drugs. In many cases, however, patients were found to spontaneously recover from their amnesia on their own accord so no treatment was required.
Memory distrust syndrome is a condition coined by Gísli Guðjónsson and James MacKeith in 1982, in which an individual doubts the accuracy of their memory concerning the content and context of events of which they have experienced. Since the individual does not trust their own memory, they will commonly depend on outside sources of information rather than using their ability for recollection. Some believe that this may be a defense or coping mechanism to a preexisting faulty memory state such as Alzheimer's disease, amnesia, or possibly dementia.
The condition is generally considered to be related to source amnesia, which involves the inability to recall the basis for factual knowledge. The main difference between the two is that source amnesia is a lack of knowing the basis of knowledge, whereas memory distrust syndrome is a lack of believing the knowledge that exists. The fact that an individual lacks the trust in their own memory implies that the individual would have a reason or belief that would prevent them from the trust that most of us have in our recollections. Cases concerning memory distrust syndrome have led to documented false confessions in court cases.
One subsequent human study found no effects of vasopressin on memory. The nonsignificant results were attributed to the study's many potential flaws, particularly its small sample size, the inability of vasopressin to penetrate the blood brain barrier when administered as a nasal spray, inadequate dosing and differences in severity of head injury between the samples. However, Eames et al. (1999) found statistically significant improvements on several tests of memory with the use of a vasopressin nasal spray, with no reported ill effects. Although the degree of improvement was mild, and it could be attributed to numerous other factors of the rehabilitative program, the lack of any ill effects suggests that vasopressin is, at the least, a possible enhancement for a treatment regimen.
The main symptom of memory distrust syndrome is the lack of belief in one's own memory, however this comes with the side effect of using outside sources for information. The individual may have their own memory, but will readily change it depending on chosen outside sources. The memories that they have may be correct, but due to their distrust they will still alter their belief of what is true if contrary information is suggested.
For example, a person has a memory of a house and recalls it to be white. Then, a trusted family member begins talking with them and suggests that it was red instead. The afflicted individual will then believe the house was red despite their recollection of it being white. It is unknown if the person's memory of the house is permanently altered; however, they will say that the house was red regardless of the memory's condition.
Also, this does not necessarily allow for confabulatory memory fabrication. Currently it is not believed that an afflicted individual will readily believe an outside source on a memory of which the person is not involved, such as a randomly shared story. This further suggests that memory distrust syndrome solely alters the individual's currently retrievable memories, and not randomized information.
A false memory is the psychological phenomenon where a person recalls something that did not happen. False memory is often considered in legal cases regarding childhood sexual abuse. This phenomenon was initially investigated by psychological pioneers Pierre Janet and Sigmund Freud. Freud wrote "The Aetiology of Hysteria", where he discussed repressed memories of childhood sexual trauma in their relation to hysteria. Elizabeth Loftus has, since her debuting research project in 1974, been a lead researcher in memory recovery and false memories. False memory syndrome recognizes false memory as a prevalent part of one's life in which it affects the person's mentality and day-to-day life. False memory syndrome differs from false memory in that the syndrome is heavily influential in the orientation of a person's life, while false memory can occur without this significant effect. The syndrome takes effect because the person believes the influential memory to be true. However, its research is controversial and the syndrome is excluded from identification as a mental disorder and, therefore, is also excluded from the "Diagnostic and Statistical Manual of Mental Disorders". False memory is an important part of psychological research because of the ties it has to a large number of mental disorders, such as PTSD.
Fragmentation of memory is a memory disorder in when an individual is unable to associate the context of the memories to their autobiographical (episodic) memory. The explicit facts and details of the events may be known to the person (semantic memory). However, the facts of the events retrieve none of the effective and somatic elements of the experience. Therefore, the emotional and personal content of the memories can't be associated with the rest of the memory. Fragmentation of memory can occur for relatively recent events as well.
The impaired person usually suffers from physical damage to or underdevelopment of the hippocampus. This may be due to a genetic disorder or be the result of trauma, such as post-traumatic stress disorder. Brain dysfunction often has other related consequences, such as oversensitivity to some stimuli, impulsiveness, lack of direction in life, occasional aggressiveness, a distorted perception of oneself, and impaired ability to empathize with others, which is usually masked.
Confabulations can also be detected using a free recall task, such as a self-narrative task. Participants are asked to recall stories (semantic or autobiographical) that are highly familiar to them. The stories recalled are encoded for errors that could be classified as distortions in memory. Distortions could include falsifying true story elements or including details from a completely different story. Errors such as these would be indicative of confabulations.
Diaschisis, as mentioned earlier, has been linked to the mechanism of PTA. The noradrenergic systems may play a role in diaschisis. Norepinephrine, also known as noradrenalin, is a catecholamine neurotransmitter. Administering a norepinephrine receptor agonist (a substance that initiates a cell response when it binds with a receptor) to patients promoted the recovery of memory and many other cognitive functions after a traumatic brain injury. Conversely, the administration of norpinephrine antagonists slowed recovery, and could lead to the reinstatement of deficits when administered after recovery. Noradrenergic antagonists were not prescribed for the purposes of slowing the recovery of memory. Rather, these findings are based on the effects of other commonly prescribed drugs that happen to block noradrenergic receptors. The alpha-1 adrenergic receptor is specifically implicated. Although it has not yet been thoroughly investigated, there is potential for stimulants, which promote catecholamine release, to be an effective treatment in the early stages of recovery from brain trauma, and these positive effects could reduce the symptoms of PTA.
False memory syndrome (FMS) describes a condition in which a person's identity and relationships are affected by memories that are factually incorrect but that they strongly believe. Peter J. Freyd originated the term, which the False Memory Syndrome Foundation (FMSF) subsequently popularized. The term is not recognized as a psychiatric illness in any of the medical manuals, such as the ICD-10 or the DSM-5; however, the principle that memories can be altered by outside influences is overwhelmingly accepted by scientists.
False memories may be the result of recovered memory therapy, a term also defined by the FMSF in the early 1990s, which describes a range of therapy methods that are prone to creating confabulations. Some of the influential figures in the genesis of the theory are forensic psychologist Ralph Underwager, psychologist Elizabeth Loftus, and sociologist Richard Ofshe.
Fragmentation of memory is a type of memory disruption pertaining to the flaws or irregularities in sequences of memories, "coherence, and content” in the narrative or story of the event. During a traumatic experience, memories can be encoded irregularly which creates imperfections in the memory. It is also described as a memory that has been jumbled, confused, or repeated unnecessarily.
Many forms of amnesia fix themselves without being treated. However, there are a few ways to cope with memory loss if that is not the case. One of these ways is cognitive or occupational therapy. In therapy, amnesiacs will develop the memory skills they have and try to regain some they have lost by finding which techniques help retrieve memories or create new retrieval paths. This may also include strategies for organizing information to remember it more easily and for improving understanding of lengthy conversation.
Another coping mechanism is taking advantage of technological assistance, such as a personal digital device to keep track of day-to-day tasks. Reminders can be set up for appointments, when to take medications, birthdays and other important events. Many pictures can also be stored to help amnesiacs remember names of friends, family and co-workers. Notebooks, wall calendars, pill reminders and photographs of people and places are low-tech memory aids that can help as well.
While there are no medications available to treat amnesia, underlying medical conditions can be treated to improve memory. Such conditions include but are not limited to low thyroid function, liver or kidney disease, stroke, depression, bipolar disorder and blood clots in the brain. Wernicke–Korsakoff syndrome involves a lack of thiamin and replacing this vitamin by consuming thiamin-rich foods such as whole-grain cereals, legumes (beans and lentils), nuts, lean pork, and yeast. Treating alcoholism and preventing alcohol and illicit drug use can prevent further damage, but in most cases will not recover lost memory.
Although improvements occur when patients receive certain treatments, there is still no actual cure remedy for amnesia so far. To what extent the patient recovers and how long the amnesia will continue depends on the type and severity of the lesion.
False memory syndrome is a condition in which a person's identity and interpersonal relationships center on a memory of a traumatic experience that is objectively false but that the person strongly believes occurred.
The FMS concept is controversial, and the Diagnostic and Statistical Manual of Mental Disorders does not include it. Paul R. McHugh, member of the FMSF, stated that the term was not adopted into the fourth version of the manual due to the pertinent committee being headed by believers in recovered memory.
Repressed memories are memories that have been unconsciously blocked due to the memory being associated with a high level of stress or trauma. The theory postulates that even though the individual cannot recall the memory, it may still be affecting them consciously, and that these memories can emerge later into the consciousness. Ideas on repressed memory hiding trauma from awareness were an important part of Sigmund Freud's early work on psychoanalysis. He later took a different view.
The existence of repressed memories is an extremely controversial topic in psychology; although some studies have concluded that it can occur in a varying but generally small percentage of victims of trauma, many other studies dispute its existence entirely. Some psychologists support the theory of repressed memories and claim that repressed memories can be recovered through therapy, but most psychologists argue that this is in fact rather a process through which false memories are created by blending actual memories and outside influences. One study concluded that repressed memories were a cultural symptom due to the lack of written proof of their existence before the nineteenth century, but its results were disputed by some psychologists, and the lack of written proof was eventually partially disproven.
According to the American Psychological Association, it is not possible to distinguish repressed memories from false ones without corroborating evidence. The term repressed memory is sometimes compared to the term dissociative amnesia, which is defined in the DSM-V as an “inability to recall autobiographical information. This amnesia may be localized (i.e., an event or period of time), selective (i.e., a specific aspect of an event), or generalized (i.e., identity and life history).”
According to the Mayo Clinic, amnesia refers to any instance in which memories stored in the long-term memory are completely or partially forgotten, usually due to brain injury.
According to proponents of the existence of repressed memories, such memories can be recovered years or decades after the event, most often spontaneously, triggered by a particular smell, taste, or other identifier related to the lost memory, or via suggestion during psychotherapy.
Amnesia is partial or complete loss of memory that goes beyond mere forgetting. Often it is temporary and involves only part of a person's experience. Amnesia is often caused by an injury to the brain, for instance after a blow to the head, and sometimes by psychological trauma. Anterograde amnesia is a failure to remember new experiences that occur after damage to the brain; retrograde amnesia is the loss of memories of events that occurred before a trauma or injury. For a memory to become permanent (consolidated), there must be a persistent change in the strength of connections between particular neurons in the brain. Anterograde amnesia can occur because this consolidation process is disrupted; retrograde amnesia can result either from damage to the site of memory storage or from a disruption in the mechanisms by which memories can be retrieved from their stores. Many specific types of amnesia are recognized, including:
- Childhood amnesia is the normal inability to recall memories from the first three years of life. Sigmund Freud observed that not only do humans not remember anything from birth to three years, but they also have “spotty” recollection of anything occurring from three to seven years of age. There are various theories as to why this occurs: some believe that language development is important for efficient storage of long-term memories; others believe that early memories do not persist because the brain is still developing.
- A fugue state, formally dissociative fugue, is a rare condition precipitated by a stressful episode. It is characterized by episode(s) of traveling away from home and creating a new identity.
The form of amnesia that is linked with recovered memories is dissociative amnesia (formerly known as psychogenic amnesia). This results from a psychological cause, not by direct damage to the brain, and is a loss of memory of significant personal information, usually about traumatic or extremely stressful events. Usually this is seen as a gap or gaps in recall for aspects of someone's life history, but with severe acute trauma, such as during wartime, there can be a sudden acute onset of symptoms.
Approaches used to treat those who suffer from anterograde amnesia often use interventions which focus on compensatory techniques, such as beepers, written notes, diaries or through intensive training programs involving the active participation of the individual concerned, along with their supporting network of family and friends.
In this perspective, environmental adaptation techniques are used, such as the compensatory technique education to training (exercise), organizational strategies, visual imagery and verbal labeling. In addition, other techniques are also used in rehabilitation, such as implicit tasks, speech and mnemotechnic methods.
So far, it has been proven that education techniques of compensatory strategies for memory disorders are effective in individuals with minor traumatic brain injuries. In moderately or severely injured individuals, effective interventions are those appealing to external aids, such as reminders in order to facilitate particular knowledge or skill acquisition. Reality orientation techniques are also considered; Their purpose is to enhance orientation using stimulation and repetition of the basic orientation information. These techniques are regularly applied in populations of patients primarily presenting with dementia and head-injured patients.
Source amnesia is the inability to remember where, when or how previously learned information has been acquired, while retaining the factual knowledge. This branch of amnesia is associated with the malfunctioning of one's explicit memory. It is likely that the disconnect between having the knowledge and remembering the context in which the knowledge was acquired is due to a dissociation between semantic and episodic memory – an individual retains the semantic knowledge (the fact), but lacks the episodic knowledge to indicate the context in which the knowledge was gained.
Memory representations reflect the encoding processes during acquisition. Different types of acquisition processes (e.g.: reading, thinking, listening) and different types of events (e.g.: newspaper, thoughts, conversation) will produce mental depictions that perceptually differ from one another in the brain, making it harder to retrieve where information was learned when placed in a different context of retrieval. Source monitoring involves a systematic process of slow and deliberate thought of where information was originally learned. Source monitoring can be improved by using more retrieval cues, discovering and noting relations and extended reasoning.
Source amnesia is not a rare phenomenon – everybody experiences it on a near daily basis as, for much of our knowledge, it is important to remember the knowledge itself, rather than its source. However, there are extreme examples of source amnesia caused by a variety of factors.
Hyperthymesia is the condition of possessing an extremely detailed autobiographical memory. People with hyperthymesia remember an abnormally vast number of their life experiences.
American neurobiologists Elizabeth Parker, Larry Cahill, and James McGaugh (2006) identified two defining characteristics of hyperthymesia: spending an excessive amount of time thinking about one's past, and displaying an extraordinary ability to recall specific events from one's past. The word "hyperthymesia" derives from Ancient Greek: "hyper-" ("excessive") and "thymesis" ("remembering").
When someone is suffering from RA, their memory cannot be recovered from simply being told personal experiences and their identity. This is called reminder effect or reminder treatment. The reminder effect consists of re-exposing the patient to past personal information, which cannot reverse RA. Thus, reminding the patient details of their life has no scientific bearings on recovering memory. Fortunately, memory can be and usually is recovered due to spontaneous recovery and plasticity.
The DSM-IV-TR states that the fugue may have a duration from days to months, and recovery is usually rapid. However, some cases may be refractory. An individual usually has only one episode.
Childhood amnesia, also called infantile amnesia, is the inability of adults to retrieve episodic memories which are memories of specific events (times, places, associated emotions, and other contextual who, what, when, and where) before the age of 2–4 years, as well as the period before age 10 of which adults retain fewer memories than might otherwise be expected given the passage of time. The development of a cognitive self is also thought by some to have an effect on encoding and storing early memories. Some research has demonstrated that children can remember events from the age of 1, but that these memories may decline as children get older.
Most psychologists differ in defining the offset of childhood amnesia. Some define it as the age from which a first memory can be retrieved. This is usually at the age of 3 or 4, but it can range from 2 to 8 years. Changes in encoding, storage and retrieval of memories during early childhood are all important when considering childhood amnesia. Some other research shows differences between gender and culture, which is implicated in the development of language. Childhood amnesia is particularly important to consider in regard to false memories and the development of the brain in early years. Proposed explanations of childhood amnesia are Freud's trauma theory, neurological development, development of the cognitive self, emotion and language.
Psychogenic amnesia, also known as dissociative amnesia, is a memory disorder characterized by sudden retrograde episodic memory loss, said to occur for a period of time ranging from hours to years. More recently, "dissociative amnesia" has been defined as a dissociative disorder "characterized by retrospectively reported memory gaps. These gaps involve an inability to recall personal information, usually of a traumatic or stressful nature." In a change from the DSM-IV to the DSM-5, dissociative fugue is now subsumed under dissociative amnesia.
The atypical clinical syndrome of the memory disorder (as opposed to organic amnesia) is that a person with psychogenic amnesia is profoundly unable to remember personal information about themselves; there is a lack of conscious self-knowledge which affects even simple self-knowledge, such as who they are. Psychogenic amnesia is distinguished from organic amnesia in that it is supposed to result from a nonorganic cause; no structural brain damage or brain lesion should be evident but some form of psychological stress should precipitate the amnesia, however psychogenic amnesia as a memory disorder is controversial.
Clinically induced RA has been achieved using different forms of electrical induction.
- Electroconvulsive therapy (ECT), used as a depression therapy, can cause impairments in memory. Tests show that information of days and weeks before the ECT can be permanently lost. The results of this study also show that severity of RA is more extreme in cases of bilateral ECT rather than unilateral ECT. Impairments can also be more intense if ECT is administered repetitively (sine wave simulation) as opposed to a single pulse (brief-pulse stimulation).
- Electroconvulsive shock (ECS): The research in this field has been advanced by using animals as subjects. Researchers induce RA in rats, for example, by giving daily ECS treatments. This is done to further understand RA.
Individuals with hyperthymesia can recall almost every day of their lives in near perfect detail, as well as public events that hold some personal significance to them. Those affected describe their memories as uncontrollable associations; when they encounter a date, they "see" a vivid depiction of that day in their heads. Recollection occurs without hesitation or conscious effort.
It is important to draw a distinction between those with hyperthymesia and those with other forms of exceptional memory, who generally use mnemonic or similar rehearsal strategies to memorize long strings of subjective information. Memories recalled by hyperthymestic individuals tend to be personal, autobiographical accounts of both significant and mundane events in their lives. This extensive and highly unusual memory does not derive from the use of mnemonic strategies; it is encoded involuntarily and retrieved automatically. Despite being able to remember the day of the week on which a particular date fell, hyperthymestics are not calendrical calculators like some people with autism or savant syndrome. Rather, hyperthymestic recall tends to be constrained to a person's lifetime and is believed to be a subconscious process.
Although hyperthymestics are not necessarily autistic, and likewise savants do not necessarily memorize autobiographical information, certain similarities exist between the two conditions. Like autistic savants, some individuals with hyperthymesia may also have an unusual and obsessive interest in dates. Russian psychologist Alexander Luria documented the famous case of mnemonist Solomon Shereshevsky, who was quite different from the first documented hyperthymestic known as AJ (real name Jill Price) in that Shereshevskii could memorize virtually unlimited amounts of information deliberately, while AJ could not – she could only remember autobiographical information (and events she had personally seen on the news or read about). In fact, she was not very good at memorizing anything at all, according to the study published in "Neurocase". Hyperthymestic individuals appear to have poorer than average memory for arbitrary information. Another striking parallel drawn between the two cases was that Shereshevsky exemplified an interesting case of synesthesia and it has been suggested that superior autobiographical memory is intimately tied to time-space synaesthesia.