Behaviorally spontaneous confabulation in limbic encephalitis: the roles of reality filtering and strategic monitoring

Impaired attention mechanisms in confabulating patients: A VLSM and DWI study

Attention is one of the most studied cognitive functions in brain-damaged populations or neurological syndromes, as its malfunction can be related to deficits in other higher cognitive functions. In the present study, we aimed at delimiting the attention deficits of a sample of brain-injured patients presenting confabulations by assessing their performance on alertness, spatial orienting, and executive control tasks. Confabulating patients, who present false memories or beliefs without intention to deceive, usually show memory deficits and/or executive dysfunction. However, it is also likely that attention processes may be impaired in patients showing confabulations. Here, we compared confabulating patients' attention performance to a lesion control group and a healthy control group. Confabulating patients' mean overall accuracy was lower than the one of healthy and lesion controls along the three experimental tasks. Importantly, confabulators presented a greater Simon congruency effect than both lesion controls and healthy controls in the presence of predictive spatial cues, besides a lower percentage of hits and longer RTs in the Go-NoGo task, demonstrating deficits in executive control. They also showed a higher reliance on alerting and spatially predictive orienting cues in the context of a deficient performance. Grey and white matter analyses showed that patients' percentage of hits in the Go-NoGo task was related to damage to the right inferior frontal gyrus (pars triangularis and pars opercularis), whereas the integrity of the right inferior fronto-occipital fasciculus was negatively correlated with their alertness effect. These results are consistent with previous literature highlighting an executive dysfunction in confabulating patients, and suggest that some additional forms of attention, such as alertness and spatial orienting, could be selectively impaired in this clinical syndrome.

Fetal alcohol spectrum disorder and confabulation in psycholegal settings: A beginner's guide for criminal justice, forensic mental health, and legal interviewers

Fetal alcohol spectrum disorders (FASD) are neurodevelopmental/neurobehavioral conditions caused by prenatal alcohol exposure (PAE). Impairments caused by PAE contribute to the over-representation of individuals with FASD in the United States juvenile and adult criminal justice systems. These same impairments can equally impact on individuals with FASD who are witnesses to or victims of crime who also have to navigate the complexities of the criminal justice system. Difficulties include increased susceptibility to confabulation throughout the legal process that, in turn, can contribute to increased rates of poor outcomes including false confessions and wrongful convictions. Individuals with FASD are particularity at risk of confabulation when they are subjected to tactics, such as stressful and anxiety-provoking situations, threats, and leading, suggestive, or coercive questioning. Many professionals in the forensic context are unfamiliar with FASD or related confabulation risk and may unintentionally utilize tactics that intensify impacts of pre-existing impairment. This article serves as a beginner's guide for professionals working in criminal justice settings by (a) providing research-based overviews of FASD and confabulation, (b) describing how FASD may lead to confabulation, and (c) suggesting ways that professionals can modify protocols when interacting with individuals with FASD. Suggestions in this article hold the potential to decrease the risk of confabulation in the criminal justice system and decrease problematic outcomes, such as false confessions and wrongful convictions among individuals with FASD.

Confabulation, amnesia and motor memory loss as a presentation of apparent ITPR1 antibody autoimmune encephalitis

A 59-year-old woman presented to the hospital with acute, hypoactive altered mental status. Her symptoms had begun 3 days prior when she developed hallucinations, urinary and faecal incontinence, and somnolence. She also exhibited confabulations, amnesia, motor memory loss and a wide-based gait. Medical, psychiatric and neurological evaluations including imaging and laboratory workup were unrevealing. Treatment for possible Wernicke encephalopathy and psychosis with high-dose intravenous thiamine and antipsychotic medications did not lead to improvement. After discharge, a send-out cerebrospinal fluid autoimmune encephalitis panel resulted positive for the newly identified neuronal inositol triphosphate receptor one (ITPR1) antibody. This prompted readmission for intravenous steroids, plasmapheresis and intravenous immunoglobulin, which yielded mild clinical improvement. Here, we describe confabulations and psychiatric symptoms as novel manifestations of the primary presentation of anti-ITPR1 encephalitis in an effort to promote faster recognition of this disease and early initiation of treatment in suspected cases.

Confabulations in Alcoholic Korsakoff's Syndrome: A Factor Analysis of the Nijmegen-Venray Confabulation List

Confabulations generally refer to the emergence of memories of experiences and events that, in reality, never took place, and which are unintentionally produced. They are frequently observed in alcoholic Korsakoff's syndrome. The aim of the current study was to validate the Nijmegen-Venray Confabulation List (NVCL), an observation scale for quantifying both spontaneous and provoked confabulations. The NVCL was completed for 252 patients with alcoholic Korsakoff's syndrome. Exploratory and confirmatory factor analyses were conducted to test three- and four-factor models of the NVCL structure. A four-factor model (provoked confabulations, spontaneous confabulations, severity of spontaneous confabulations, and distorted sense of reality) fitted the data better than the initially proposed three-factor model (provoked confabulations, spontaneous confabulations, memory, and orientation). The new instrument is therefore referred to as the NVCL-R. We encourage clinicians to include the assessment of confabulations in the neuropsychological examination, and to do so with validated instruments such as the NVCL-R.

Effectiveness of a neuropsychological treatment for confabulations after brain injury: A clinical trial with theoretical implications

Confabulators consistently generate false memories without intention to deceive and with great feelings of rightness. However, to our knowledge, there is currently no known effective treatment for them. In order to fill this gap, our aim was to design a neuropsychological treatment based on current theoretical models and test it experimentally in 20 confabulators sequentially allocated to two groups: an experimental and a control group. The experimental group received nine sessions of treatment for three weeks (three sessions per week). The sessions consisted of some brief material that participants had to learn and recall at both immediate and delayed time points. After this, patients were given feedback about their performance (errors and correct responses). Pre- and post-treatment measurements were recorded. Confabulators in the control group were included in a waiting list for three weeks, performed the pre- and post- measurements without treatment, and only then received the treatment, after which a post-treatment measurement was recorded. This applied to only half of the participants; the other half quit the study prematurely. Results showed a significant decrease in confabulations and a significant increase in correct responses in the experimental group; by contrast, patients in the control group did not improve during the waiting list period. Only control group patients who subsequently received the treatment after serving as controls improved. The effects of the treatment were generalized to patients’ everyday lives, as reported by relatives, and persisted over time. This treatment seems to be effective and easy to implement and consequently of clinical interest. Moreover, it also has theoretical implications regarding the processes related to the genesis and/or maintenance of confabulations. In particular, results point to a deficit in early stages of memory retrieval with the preservation of later strategic monitoring processes. Specifically, some of the processes involved may include selective attention or early conflict detection deficits. Future research should test these hypotheses.

Confabulation: Developing the 'emotion dysregulation' hypothesis

Confabulations offer unique opportunities for establishing the neurobiological basis of delusional thinking. As regards causal factors, a review of the confabulation literature suggests that neither amnesia nor executive impairment can be the sole (or perhaps even the primary) cause of all delusional beliefs - though they may act in concert with other factors. A key perspective in the modern literature is that many delusions have an emotionally positive or 'wishful' element, that may serve to modulate or manage emotional experience. Some authors have referred to this perspective as the 'emotion dysregulation' hypothesis. In this article we review the theoretical underpinnings of this approach, and develop the idea by suggesting that the positive aspects of confabulatory states may have a role in perpetuating the imbalance between cognitive control and emotion. We draw on existing evidence from fields outside neuropsychology, to argue for three main causal factors: that positive emotions are related to more global or schematic forms of cognitive processing; that positive emotions influence the accuracy of memory recollection; and that positive emotions make people more susceptible to false memories. These findings suggest that the emotions that we want to feel (or do not want to feel) can influence the way we reconstruct past experiences and generate a sense of self - a proposition that bears on a unified theory of delusional belief states.

Autobiographical age awareness disturbance syndrome in autoimmune limbic encephalitis: two case reports

Background

Autobiographical memory is a form of episodic memory characterized by a sense of time and consciousness that enables an individual to subjectively re-experience his or her past. As part of this mental re-enactment, the past is recognized relative to the present. Dysfunction of this memory system may lead to confusion regarding the present perception of time.

Case presentation

Two Japanese women (42 and 55 years old) temporarily believed they were living in their past during a course of autoimmune limbic encephalitis. Their autobiographical memories and behaviour reflected their self-estimated age, and they could not recall memories experienced beyond that age. More surprisingly, their subjective age estimations and autobiographical memories were transiently corrected when they were made aware of their true age. Disorientation, anterograde amnesia, and retrograde amnesia were common additional symptoms. Neuroimaging suggested disturbances in medial temporal and orbitofrontal brain regions in both cases.

Conclusions

This syndrome is characterized by three elements: 1) failure to subjectively recognize the present; 2) inability to suppress irrelevant past memories; and 3) transient restitution of awareness of the present through realization of the individual’s true age. We defined this syndrome as ‘autobiographical age awareness disturbance’, and focused our investigation on the role of age self-awareness. If recall of relevant and suppression of irrelevant past memories are both necessary to subjectively recognize the present relative to the past, dysfunction of medial temporal and orbitofrontal brain regions is predicted to lead to abnormal subjective placement in time. However, the subjective experience of age tends to be an important informational component for retrieving remote autobiographical memories. This suggests that correct age awareness is essential for the proper recognition of the remote past in relation to the present. This is the first report to focus on the relationship between subjective temporal orientation and age self-awareness. While the role of age awareness in this process is still unclear, investigating autobiographical age awareness disturbance as a part of subjective temporal awareness dysfunction can be useful in understanding the processes underlying human time recognition.

A neurophenomenological model for the role of the hippocampus in temporal consciousness. Evidence from confabulation

Confabulation, the production of statements or actions that are unintentionally incongruous to the subject's history, background, present and future situation, is a rather infrequent disorder with different aetiologies and anatomical lesions. Although they may differ in many ways, confabulations show major similarities. Their content, with some minor exceptions, is plausible and therefore indistinguishable from true memories, unless one is familiar with the patient's history, background, present and future situation. They extend through the whole individuals' temporality, including their past, present and future. Accordingly, we have proposed that rather than a mere memory disorder; confabulation reflects a distortion of Temporal Consciousness (TC), i.e., a specific form of consciousness that allows individuals to locate objects and events according to their subjective temporality. Another feature that confabulators share is that, regardless of their lesion's location, they all have a relatively preserved hippocampus (Hip), at least unilaterally. In this article, we review data showing differences and similarities among forms of confabulation. We then describe a model showing that the hippocampus is crucial both for the normal functioning of TC and as the generator of confabulations, and that different types of confabulation can be traced back to a distortion of TC resulting from damage or disconnection of brain areas directly or indirectly connected to the hippocampus. We conclude by comparing our model with other models of memory and confabulation.

Orbitofrontal reality filtering

Decades of research have deepened our understanding of how the brain forms memories and uses them to build our mental past and future. But how does it determine whether an evoked memory refers to the present and can be acted upon? The study of patients who confuse reality, as evident from confabulation and disorientation, has opened ways to explore this vital capacity. Results indicate that the brain recurs to a phylogenetically old faculty of the orbitofrontal cortex - extinction - and structures of the reward system to keep thought and behavior in phase with reality.

Isolated prospective confabulation in Wernicke-Korsakoff syndrome: a case for reality filtering

A 57-year-old man suffered severe amnesia and disorientation, accompanied by content-specific confabulation, due to an alcoholic Wernicke-Korsakoff syndrome. For months, he was deeply concerned about a single obligation that he thought he had to respond to, but which he had already assumed 20 years previously. This monothematic, prospective confabulation was associated with failures of reality filtering as previously documented in behaviorally spontaneous confabulation and disorientation: the patient failed to suppress the interference of currently irrelevant memories and to abandon anticipations that were no longer valid (impaired extinction capacity). Magnetic resonance imaging showed damage to the mamillary bodies and the dorsomedial thalamic nucleus. Positron emission tomography (FDG-PET) showed extended orbitofrontal hypometabolism. We suggest that isolated prospective confabulation shares the core feature (acts and thoughts based on currently irrelevant memory), mechanism (failure of reality filtering), and anatomical basis (orbitofrontal dysfunction) with behaviorally spontaneous confabulations.