Recall of fabricated, misinterpreted or distorted memories
Confabulation is a memory error consisting of the production of fabricated, distorted, or misinterpreted memories about oneself or the world. It is generally associated with certain types of brain damage (especially aneurysm in the anterior communicating artery) or a specific subset of dementias. While still an area of ongoing research, the basal forebrain is implicated in the phenomenon of confabulation. People who confabulate present with incorrect memories ranging from subtle inaccuracies to surreal fabrications, and may include confusion or distortion in the temporal framing (timing, sequence or duration) of memories. In general, they are very confident about their recollections, even when challenged with contradictory evidence.
Confabulation occurs when individuals mistakenly recall false information, without intending to deceive. Brain damage, dementia, and anticholinergic toxidrome can cause this distortion. Two types of confabulation exist: provoked and spontaneous, with two distinctions: verbal and behavioral. Verbal statements, false information, and the patient's unawareness of the distortion are all associated with this phenomenon. Personality structure also plays a role in confabulation.
Numerous theories have been developed to explain confabulation. theories suggest that cognitive dysfunction causes the distortion. Self-identity theories posit that people confabulate to preserve themselves. The temporality theory believes that confabulation occurs when an individual cannot place events properly in time. The monitoring and strategic retrieval account theories argue that confabulation arises when individuals cannot recall memories correctly or monitor them after retrieval. The executive control and fuzzy-trace theories also attempt to explain why confabulation happens.
Confabulation can occur with nervous system injuries or illnesses, including Korsakoff's syndrome, Alzheimer's disease, schizophrenia, and traumatic brain injury. It is believed that the right frontal lobe of the brain is damaged, causing false memories. Children are especially susceptible to forced confabulation as they are highly impressionable. Feedback can increase confidence in false memories. In rare cases, confabulation occurs in ordinary individuals.
Different memory tests, including recognition tasks and free recall tasks, can be used to study confabulation. Treatment depends on the underlying cause of the distortion. Ongoing research aims to develop a standard test battery to discern between different types of confabulations, distinguish delusions from confabulations, understand the role of unconscious processes, and identify pathological and nonpathological confabulations.
Description.
Confabulation was originally defined as "the emergence of memories of events and experiences which never took place".
Confabulation is distinguished from lying as there is no intent to deceive and the person is unaware the information is false. Although individuals can present blatantly false information, confabulation can also seem to be coherent, internally consistent, and relatively normal.
Most known cases of confabulation are symptomatic of brain damage or dementias, such as aneurysm, Alzheimer's disease, or Wernicke–Korsakoff syndrome (a common manifestation of thiamine deficiency caused by alcohol use disorder). Additionally confabulation often occurs in people with anticholinergic toxidrome when interrogated about bizarre or irrational behaviour.
Confabulated memories of all types most often occur in autobiographical memory and are indicative of a complicated and intricate process that can be led astray at any point during encoding, storage, or recall of a memory. This type of confabulation is commonly seen in Korsakoff's syndrome.
Distinctions.
Several forms of confabulation have been distinguished which vary in terms of behaviour, mechanism, and location of brain damage. The most common distinction is between the following two types:
Signs and symptoms.
Confabulation is associated with several characteristics:
Theories.
Theories of confabulation range in emphasis. Some theories propose that confabulations represent a way for memory disabled people to maintain their self-identity. Other theories use neurocognitive links to explain the process of confabulation. Still other theories frame confabulation around the more familiar concept of delusion. Other researchers frame confabulation within the fuzzy-trace theory. Finally, some researchers call for theories that rely less on neurocognitive explanations and more on epistemic accounts.
Neuropsychological theories.
The most popular theories of confabulation come from the field of neuropsychology or cognitive neuroscience. Controlled experimental evidence is, however, scarce. Research suggests that confabulation is associated with dysfunction of cognitive processes that control the retrieval from long-term memory. Frontal lobe damage often disrupts this process, preventing the retrieval of information and the evaluation of its output. Furthermore, researchers argue that confabulation is a disorder resulting from failed "reality monitoring/source monitoring" (i.e. deciding whether a memory is based on an actual event or whether it is imagined). Some neuropsychologists suggest that errors in retrieval of information from long-term memory that are made by normal subjects involve different components of control processes than errors made by confabulators. Fantastic confabulations have been attributed to a dysfunction of the Supervisory System, which is believed to be a function of the frontal cortex.
Temporality theory.
Support for the temporality account suggests that confabulations occur when an individual is unable to place events properly in time. Thus, an individual might correctly state an action they performed, but say they did it yesterday, when they did it weeks ago. In the Memory, Consciousness, and Temporality Theory, confabulation occurs because of a deficit in temporal consciousness or awareness.
Monitoring theory.
Along a similar notion are the theories of reality and source monitoring theories. In these theories, confabulation occurs when individuals incorrectly attribute memories as reality, or incorrectly attribute memories to a certain source. Thus, an individual might claim an imagined event happened in reality, or that a friend told him/her about an event he/she actually heard about on television.
Strategic retrieval account theory.
Supporters of the strategic retrieval account suggest that confabulations occur when an individual cannot actively monitor a memory for truthfulness after its retrieval. An individual recalls a memory, but there is some deficit after recall that interferes with the person establishing its falseness.
Executive control theory.
Still others propose that all types of false memories, including confabulation, fit into a general memory and executive function model. In 2007, a framework for confabulation was proposed that stated confabulation is the result of two things: Problems with executive control and problems with evaluation. In the executive control deficit, the incorrect memory is retrieved from the brain. In the evaluative deficit, the memory will be accepted as a truth due to an inability to distinguish a belief from an actual memory.
In the context of delusion theories.
Recent models of confabulation have attempted to build upon the link between delusion and confabulation. More recently, a monitoring account for delusion, applied to confabulation, proposed both the inclusion of conscious and unconscious processing. The claim was that by encompassing the notion of both processes, spontaneous versus provoked confabulations could be better explained. In other words, there are two ways to confabulate. One is the unconscious, spontaneous way in which a memory goes through no logical, explanatory processing. The other is the conscious, provoked way in which a memory is recalled intentionally by the individual to explain something confusing or unusual.
Fuzzy-trace theory.
Fuzzy-trace theory, or FTT, is a concept more commonly applied to the explanation of judgement decisions. According to this theory, memories are encoded generally (gist), as well as specifically (verbatim). Thus, a confabulation could result from recalling the incorrect verbatim memory or from being able to recall the gist portion, but not the verbatim portion, of a memory.
FTT uses a set of five principles to explain false-memory phenomena. Principle 1 suggests that subjects store verbatim information and gist information parallel to one another. Both forms of storage involve the surface content of an experience. Principle 2 shares factors of retrieval of gist and verbatim traces. Principle 3 is based on dual-opponent processes in false memory. Generally, gist retrieval supports false memory, while verbatim retrieval suppresses it. Developmental variability is the topic of Principle 4. As a child develops into an adult, there is obvious improvement in the acquisition, retention, and retrieval of both verbatim and gist memory. However, during late adulthood, there will be a decline in these abilities. Finally, Principle 5 explains that verbatim and gist processing cause vivid remembering. Fuzzy-trace Theory, governed by these 5 principles, has proved useful in explaining false memory and generating new predictions about it.
Epistemic theory.
However, not all accounts are so embedded in the neurocognitive aspects of confabulation. Some attribute confabulation to epistemic accounts. In 2009, theories underlying the causation and mechanisms for confabulation were criticized for their focus on neural processes, which are somewhat unclear, as well as their emphasis on the negativity of false remembering. Researchers proposed that an epistemic account of confabulation would be more encompassing of both the advantages and disadvantages of the process.
Presentation.
Associated neurological and psychological conditions.
Confabulations are often symptoms of various syndromes and psychopathologies in the adult population, including Korsakoff's syndrome, Alzheimer's disease, schizophrenia, and traumatic brain injury.
Wernicke–Korsakoff syndrome is a neurological disorder typically characterized by years of alcohol use disorder characterized by excessive alcohol consumption and a nutritional thiamine deficiency. Confabulation is one salient symptom of this syndrome. A study on confabulation in Korsakoff's patients found that they are subject to provoked confabulation when prompted with questions pertaining to episodic memory, not semantic memory, and when prompted with questions where the appropriate response would be "I don't know." This suggests that in these patients is "domain-specific." Korsakoff's patients who confabulate are more likely than healthy adults to falsely recognize distractor words, suggesting that false recognition is a "confabulatory behavior."
Alzheimer's disease is a condition with both neurological and psychological components. It is a form of dementia associated with severe frontal lobe . Confabulation in individuals with Alzheimer's is often more spontaneous than it is in other conditions, especially in the advanced stages of the disease. Alzheimer's patients demonstrate comparable abilities to encode information as healthy elderly adults, suggesting that impairments in encoding are not associated with confabulation. However, as seen in Korsakoff's patients, confabulation in Alzheimer's patients is higher when prompted with questions investigating episodic memory. Researchers suggest this is due to damage in the posterior cortical regions of the brain, which is a symptom characteristic of Alzheimer's disease.
Schizophrenia is a psychological disorder in which confabulation is sometimes observed. Although confabulation is usually coherent in its presentation, of schizophrenic patients are often delusional. Researchers have noted that these patients tend to make up delusions on the spot which are often fantastic and become increasingly elaborate with questioning. Unlike patients with Korsakoff's and Alzheimer's, patients with schizophrenia are more likely to confabulate when prompted with questions regarding their semantic memories, as opposed to episodic memory prompting. In addition, confabulation does not appear to be related to any memory deficit in patients. This is contrary to most forms of confabulation. Also, confabulations made by schizophrenic patients often do not involve the creation of new information, but instead involve an attempt by the patient to reconstruct actual details of a past event.
Traumatic brain injury (TBI) can also result in confabulation. Research has shown that patients with damage to the inferior medial frontal lobe confabulate significantly more than patients with damage to the posterior area and healthy controls. This suggests that this region is key in producing confabulatory responses, and that memory deficit is important but not necessary in . Additionally, research suggests that confabulation can be seen in patients with frontal lobe syndrome, which involves an insult to the frontal lobe as a result of disease or traumatic brain injury (TBI). Finally, rupture of the anterior or posterior communicating artery, subarachnoid hemorrhage, and encephalitis are also possible causes of confabulation.
Location of brain lesions.
Confabulation is believed to be a result of damage to the right frontal lobe of the brain. In particular, damage can be localized to the ventromedial frontal lobes and other structures fed by the anterior communicating artery (ACoA), including the basal forebrain, septum, fornix, cingulate gyrus, cingulum, anterior hypothalamus, and head of the caudate nucleus. 
Behaviourally spontaneous confabulation may occur in the context of dementia or the Wernicke–Korsakoff syndrome where brain damage is difficult to localise. If it is due to circumscribed brain damage (e.g., after ruptured aneurysm of the anterior communicating artery, traumatic brain injury, stroke), lesions involved the posterior medial orbitofrontal cortex (area 13) or an area directly connected with it. 
Developmental differences.
While some recent literature has suggested that older adults may be more susceptible than their younger counterparts to have false memories, the majority of research on forced confabulation centers around children. Children are particularly susceptible to forced confabulations based on their high suggestibility. When forced to recall confabulated events, children are less likely to remember that they had previously confabulated these situations, and they are more likely than their adult counterparts to come to remember these confabulations as real