Confabulations in alcoholic Korsakoff patients

Behavioral, neurological, and psychiatric frailty of autobiographical memory

Autobiographical-episodic memory is considered to be the most complex of the five long-term memory systems. It is autonoetic, which means, self-reflective, relies on emotional colorization, and needs the features of place and time; it allows mental time traveling. Compared to the other four long-term memory systems-procedural memory, priming, perceptual, and semantic memory-it develops the latest in phylogeny and ontogeny, and is the most vulnerable of the five systems, being easily impaired by brain damage and psychiatric disorders. Furthermore, it is characterized by its fragility and proneness to distortion due to environmental influences and subsequent information. On the brain level, a distinction has to be made between memory encoding and consolidating, memory storage, and memory retrieval. For encoding, structures of the limbic system, with the hippocampus in its center, are crucial, for storage of widespread cortical networks, and for retrieval again a distributed recollection network, in which the prefrontal cortex plays a crucial role, is engaged. Brain damage and psychiatric diseases can lead to what is called "focal retrograde amnesia." In this context, the clinical picture of dissociative or functional or psychogenic amnesia is central, as it may result in autobiographical-emotional amnesia of the total past with the consequence of an impairment of the self as well. The social environment therefore can have a major impact on the brain and on autobiographical-episodic memory processing. This article is categorized under: Psychology > Memory.

"Cinderella was attacked by the big bad wolf, but the police saved her": intrusions and confabulations on story recall in Korsakoff's syndrome and alcohol-related cognitive impairments

BACKGROUND

The relation between confabulations and intrusions in patients with Korsakoff's syndrome (KS) and patients with alcohol-related cognitive impairments (ARCI) remains under debate. This study examines (1) differences in the production of confabulations and intrusions between patients with KS and ARCI, (2) whether an altered fairy tale induces more intrusions, and (3) whether different types of intrusions were significantly related to confabulations.

METHODS

Twenty-three patients with KS and twenty-two patients with ARCI recalled three different types of stories: a novel story, a fairy tale, and a modified fairy tale. Different types of intrusions were correlated with confabulation measures.

RESULTS

Patients with KS produced more intrusions in the modified fairy tale condition than patients with ARCI, but these were unrelated to confabulations. Only unrelated intrusions were related to provoked confabulations.

CONCLUSIONS

The results of this study indicate that researchers and clinicians must be aware that in general, intrusions on memory tests should not be interpreted as confabulations. Especially spontaneous confabulations appear to be something completely different from intrusions on any type of story recall. When measuring confabulations it is crucial to use validated instruments.

"Ten dollars today or 50 dollars after one month?" Temporal discounting in Korsakoff syndrome

OBJECTIVE

Little research has investigated decision making in patients with Korsakoff syndrome (KS). Specifically, to our knowledge, there is a lack of research investigating whether patients with KS may tend to prefer immediate over future rewards (i.e., temporal discounting). Further, we investigated the relationship between temporal discounting and inhibition.

METHODS

We, for the first time, invited patients with KS and control participants to perform a temporal discounting task, in which they answered questions probing preferences between an immediate, but smaller amount of money, and a delayed, but larger amount of money (e.g., "would you prefer 10 dollars today or 50 dollars after one month?"). Furthermore, inhibition was measured using the Stroop Colour Word Test.

RESULTS

Analysis demonstrated higher temporal discounting in patients with KS than in control participants. Temporal discounting in both populations was significantly correlated with inhibition.

CONCLUSIONS

Patients with KS may have difficulties to suppress the temptation of smaller, but immediate, rewards.

The era of our lives: The memory of Korsakoff patients for the first Covid-19 pandemic lockdown in the Netherlands

Memories for worldwide and emotional events (such as 9/11) are more vividly relived and recalled than memories for everyday events. Previous studies have shown that flashbulb memories of a single event enhanced the memory strength in severe amnesia. It is currently unknown whether macro-events that stretch out over longer periods of time (weeks, months) strengthen memory even further. Our aim was therefore to investigate to what extent patients with severe amnesia, due to Korsakoff's syndrome (KS), were able to relive the first Covid-19 lockdown in the Netherlands, and whether experienced emotions enhanced reliving of the participants. We included 22 KS patients and 24 age-, education-, and gender-matched healthy controls. Covid-19 related memories were assessed by measures of autobiographical memory specificity, phenomenological reliving, emotional intensity and semantic-and episodic knowledge about the first lockdown in March 2020 - May 2020 in the Netherlands. Although amnesia patients remembered significantly fewer autobiographical details regarding the Covid-19 lockdown than healthy controls, one fourth of the KS patients recalled specific events. Amnesia patients reported levels of emotional intensity equivalent to those in the control group. Stronger autobiographical reliving was associated with higher emotional intensity. Both amnesia patients and healthy controls had higher recall of episodic than semantic lockdown related information. In conclusion, results demonstrate that information for macro-events can still be memorized and relived, most specifically when emotional valence is high, even by highly amnestic patients.

Exploring episodic and semantic contributions to past and future thinking performance in Korsakoff's syndrome

Korsakoff's syndrome (KS) is a neuropsychiatric disorder characterized by severe declarative memory disruption. While episodic memory deficits and confabulation are well documented, it remains unclear to what extent semantic memory is compromised in this syndrome. Moreover, how such impairments relate to the capacity for future-oriented thinking remains unknown. Here, we sought to determine the extent to which episodic and semantic forms of past and future thinking are impacted in KS and the interrelationship between different classes of memory in this syndrome. Twenty patients with KS and 17 matched healthy controls took part in this study. We included well-established indices of past and future thinking capacity, enabling us to compare episodic (event-based) versus semantic (nonpersonal knowledge) across past and future conditions. We also included a novel event generation task to probe implausible event simulation (i.e., spending a day on the moon). Our findings revealed marked impairments in KS across all forms of past and future thinking, as well as the generation of episodic details on the implausible event simulation task. Correlation analyses revealed significant associations between implausible event construction and episodic and semantic future thinking in KS; however, no significant associations were found between future thinking performance and confabulation. This study is the first, to our knowledge, to reveal striking impairments in the capacity for past and future thinking across episodic and semantic domains in KS. Our findings resonate with current theoretical perspectives in which the lines between episodic and semantic memory systems are viewed as increasingly blurred.

Intentional and unintentional mind-wandering in Korsakoff syndrome

Mind-wandering refers to the intentional and unintentional tendency to withdraw from the external environment and engage in internally generated thoughts. We investigated intentional and unintentional mind-wandering in patients with Korsakoff syndrome (KS). We invited 31 patients with KS and 33 control participants to answer a questionnaire probing intentional and unintentional mind-wandering. Analysis demonstrated higher intentional and unintentional mind-wandering in patients with KS than in controls. However, no significant differences were observed between intentional and unintentional mind-wandering in patients with KS or in controls. Significant positive correlations were observed between intentional and unintentional mind-wandering and depression in patients with KS but not with cognitive controls. Our results demonstrate a high intentional and unintentional tendency in patients with KS to shift attention away from the external environment to internal thoughts/feelings that are unrelated to the ongoing task. This tendency may be associated with the activation of negative thoughts/beliefs, as observed in depression.

Autobiographical memory in Korsakoff syndrome: A review

Autobiographical memory (AM) (i.e., memory for personal information) is a unique form of memory that goes beyond recalling information such as what, where and when of an event, to include what that event means and why it is important to our life story. This paper therefore reviews the available literature on AM in Korsakoff syndrome (KS). It summarizes the characteristics of AM disorders in KS patients. These disorders are mainly characterized by the difficulties that patients with KS have in retrieving and reliving specific AMs and in retrieving recent and remote memories. Another core characteristic of AM disorders in KS is confabulations. This paper hypothesizes that patients with KS may produce autobiographical confabulations to support their objectives and beliefs or even to answer a social demand or simply to share personal experiences with others. Although the current evidence demonstrates disorders of AM in KS, there is a need for more research about the characteristics of these disorders. This review thus proposes several perspectives for theoretical and clinical research.

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.

Frontolimbic affective bias and false narratives from brain disease

Since the nineteenth century, clinicians and investigators have systematically evaluated the origin of delusions and psychotic thinking. One major clue to understanding the neurobiological underpinnings of delusions is the emergence of false narratives from brain disease. In addition to delusions themselves, there are a range of other false narratives not due to deliberate lying and resulting from neurological disorders, including provoked confabulations, fantastic confabulations, false memories, magical thinking, dream delusions, and "fantastic thinking". A comparison of their characteristics, similarities, and differences suggest a hypothesis: despite different sources for their false narrative experiences, such as unusual thoughts or perceptions, all false narratives from brain disease involve erroneous or mismatched "affective biases" applied to the experiences. Affective labels usually signal the sense of rightness, sense of familiarity, and the external vs. internal origin of an experience, and they can be altered by limbic neuropathology. The location and involvement of neuropathology that facilitates false narratives involves frontolimbic regions and their connections, particularly on the right. Future investigations can focus on frontolimbic mechanisms involved in the provision of the intrinsically-linked affective biases, which indicate the nature and external/internal origin of experiences.

Future Thinking in Korsakoff Syndrome

Aims

Prior research has been mainly concerned with the ability of patients with Korsakoff syndrome (KS) to project themselves into the past. Little is known about the patients’ ability to project themselves into the future. We therefore compared past and future thinking in patients with KS.

Methods

We invited patients with KS and control participants to retrieve past events and reconstruct future events. Participants were also invited to rate subjective characteristics (i.e. time travel, emotional feeling, and visual imagery) of the past and future events.

Results

Patients with KS demonstrated low specificity, time travel, and emotional experience during past and future thinking. However, while lower emotional experience was observed in patients with KS than in the control participants during future thinking, no significant differences were observed between the two populations during past thinking. Regarding within-group comparisons, patients with KS demonstrated no significant differences between past and future thinking in terms of specificity, time travel, and visual imagery; however, they demonstrated higher emotional experience during past than during future thinking. Regarding control participants, they demonstrated no significant differences between past and future thinking in terms of specificity, time travel, emotional experience, and visual imagery.

Conclusion

Our findings demonstrate a diminished ability to construct specific future scenarios as well as a diminished subjective experience during future thinking in KS.

Confabulation Resilience of the Developing Brain: A Brief Review

OBJECTIVES

To investigate a possible confabulation resilience of the developing brain.

METHODS

We performed a literature search on confabulation in PubMed and identified all empirical studies of children and adolescents under the age of 18.

RESULTS

The analysis identified only three case studies of confabulation in children under the age of 18 of 286 empirical studies of confabulation. This reveals a striking discrepancy in the number of reported cases caused by brain injury between children and adults. We hypothesize that there may be a resilience toward confabulation in the developing brain and present three tentative explanations regarding the possible underlying mechanisms.

CONCLUSIONS

Additional awareness on the scarcity of reported cases of confabulation in children could lead to important insights on the nature of confabulation and greater understanding of the resilience and plasticity of the developing brain. (JINS, 2019, 25, 426-431).

Identification and Evaluation of Neuropsychological Tools Used in the Assessment of Alcohol-Related Cognitive Impairment: A Systematic Review

Background: Neuropsychological assessment is central to identifying and determining the extent of Alcohol-Related Cognitive Impairment (ARCI). The present systematic review aimed to synthesize and discuss the evidence appraising the neuropsychological tests used to assess ARCI in order to support clinicians and researchers in selecting appropriate tests for use with this population. Methods: We searched for studies investigating the psychometric, diagnostic and practical values of tools used in the screening, diagnosis, and assessment of Korsakoff's Syndrome (KS), Alcohol-Related Dementia (ARD), and those with a specific diagnosis of Alcohol-Related Brain Damage (ARBD). The following databases were searched in March 2016 and again in August 2018: MEDLINE, EMBASE, Psych-INFO, ProQuest Psychology, and Science Direct. Study quality was assessed using a checklist designed by the authors to evaluate the specific factors contributing to robust and clearly reported studies in this area. A total of 43 studies were included following the screening of 3646 studies by title and abstract and 360 at full-text. Meta-analysis was not appropriate due to heterogeneity in the tests and ARCI samples investigated in the studies reviewed. Instead, review findings were narratively synthesized and divided according to five domains of assessment: cognitive screening, memory, executive function, intelligence and test batteries, and premorbid ability. Effect sizes (d) were calculated to supplement findings. Results: Overall, several measures demonstrated sensitivity to the cognitive deficits associated with chronic alcoholism and an ability to differentiate between gradations of impairment. However, findings relating to the other psychometric qualities of the tests, including those important for the accurate assessment and monitoring of ARCI (e.g., test-retest reliability), were entirely absent or limited. Additionally, the synthesis of neuropsychological outcomes presented here supports the recent impetus for a move away from discrete diagnoses (e.g., KS, ARD) and the distinctions between them toward more broad and inclusive diagnostic conceptualizations of ARCI, thereby recognizing the heterogeneity in presentation. Conclusions: Based on the evidence reviewed, provisional recommendations for appropriate tests in each domain of assessment are presented, though further validation of most tests is warranted. Review findings can support efficient and evidenced-based test-selection and guide future research in this area.

Social and emotional loneliness in Korsakoff's syndrome

INTRODUCTION

Loneliness is the subjective negative evaluation of social participation and isolation. Emotional loneliness reflects the absence of close relationships, and social loneliness the absence of a social network. Although loneliness is a growing problem in modern society, studies about loneliness in patients with Korsakoff's syndrome (KS) in need of chronic care are currently missing.

METHODS

Sixty-three KS patients in long-term care and their primary caregivers reported loneliness of the patients on the De Jong Gierveld Loneliness Scale.

RESULTS

A majority of KS patients reliably reported to feel lonely on both a social and emotional level of loneliness. The caregiving professionals rated loneliness of the patients even higher. Patients that had stayed in the clinic for a longer time tended to report less social loneliness, while caregivers reported less emotional loneliness in those patients. The KS-specific neuropsychiatric symptom of confabulations and a lack of social visits had a negative impact on social loneliness as perceived by the caregivers.

CONCLUSION

Loneliness is a large problem in patients with KS that live in a long term care facility. Social loneliness can be positively influenced by creating possibilities to interact with other people, although the severity of the neuropsychiatric aspects of KS could compromise the presence of those interactions.

Intrusions and provoked and spontaneous confabulations on memory tests in Korsakoff's syndrome

INTRODUCTION

Intrusions on verbal memory tests have been used as an index for clinical confabulation. Severe memory impairments in combination with executive dysfunction have been suggested to be the underlying mechanism of confabulation, but to date, this relation is unclear. The aim of this study was (a) to examine the relation between (different types of) intrusions and confabulations in a large sample of confabulating patients with Korsakoff's syndrome (KS) and (b) to investigate whether different measures of executive functioning and memory performance are related to provoked and spontaneous confabulation.

METHOD

The Dutch version of the California Verbal Learning Test (CVLT) and various executive function and memory tests were administered to a group of 51 confabulating patients with KS. Professional caregivers rated the severity of provoked and spontaneous confabulation behavior of the patients using the Nijmegen-Venray Confabulation List-20 (NVCL-20).

RESULTS

The total number of intrusions on the CVLT was not related to either provoked or spontaneous confabulation scores. None of the CVLT intrusion scores correlated significantly with any of the confabulation scores, but we did find small-to-medium, positive correlations between unrelated intrusions and both provoked confabulations and spontaneous confabulation. Provoked confabulation behavior was associated with executive dysfunction and poorer memory performances. Spontaneous confabulation was not related to performance on measures of executive function and memory.

CONCLUSIONS

The total number of intrusions on verbal memory tests and clinical confabulations appear to be different phenomena. Only unrelated intrusions produced on the CVLT might possibly be related to confabulations. The production of provoked, but not spontaneous, confabulation is associated with executive dysfunction and memory deficits.

Beyond Cognition: Understanding Affective Impairments in Korsakoff Syndrome

As earlier research on Korsakoff syndrome (KS), a frequent neurological complication of alcohol-dependence (AD), mainly focused on cognition, affective impairments have been little investigated despite their crucial impact in AD. This article proposes new research avenues on this topic by combining two theoretical frameworks: (a) dual-process models, positing that addictions are due to an imbalance between underactivated reflective system and overactivated affective-automatic one; (b) continuity theory, postulating a gradual worsening of cognitive impairments from AD to KS. We suggest that this joint perspective may renew the current knowledge by clarifying the affective-automatic deficits in KS and their interactions with reflective impairments, but also by offering a direct exploration of the continuity between AD and KS regarding reflective and affective-automatic abilities.

Assessment of Confabulation in Patients with Alcohol-Related Cognitive Disorders: The Nijmegen-Venray Confabulation List (NVCL-20)

OBJECTIVE

Even though the first awareness of confabulations is often based on observations, only questionnaires and structured interviews quantifying provoked confabulations are available. So far, no tools have been developed to measure spontaneous confabulation. This study describes and validates an observation scale for quantifying confabulation behavior, including spontaneous confabulations, in clinical practice.

METHOD

An observation scale consisting of 20 items was developed, the Nijmegen-Venray Confabulation List-20 (NVCL-20). This scale covers spontaneous confabulation, provoked confabulation, and memory and orientation. Professional caregivers completed the NVCL-20 for 28 Korsakoff (KS) patients and 24 cognitively impaired chronic alcoholics (ALC). Their ratings were related to the Dalla Barba Confabulation Battery (DBCB), Provoked Confabulation Test (PCT), and standard neuropsychological tests.

RESULTS

The categories of the NVCL-20 have "good" to "excellent" internal consistency and inter-rater agreement. The KS patients confabulated more (both spontaneously and provoked), and more memory and orientation problems were observed. Correlations with neuropsychological test scores showed that confabulations were associated with memory deficits, but not with intrusions or tests of executive dysfunction.

CONCLUSIONS

The NVCL-20 is the first instrument that includes items addressing spontaneous confabulation. Administration is reliable, valid and feasible in clinical practice, making it a useful addition to existing confabulating measures.

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.

Revisiting the continuum hypothesis: toward an in-depth exploration of executive functions in korsakoff syndrome

Korsakoff syndrome (KS) is a neurological state mostly caused by alcohol-dependence and leading to disproportionate episodic memory deficits. KS patients present more severe anterograde amnesia than Alcohol-Dependent Subjects (ADS), which led to the continuum hypothesis postulating a progressive increase in brain and cognitive damages during the evolution from ADS to KS. This hypothesis has been extensively examined for memory but is still debated for other abilities, notably executive functions (EF). EF have up to now been explored by unspecific tasks in KS, and few studies explored their interactions with memory. Exploring EF in KS by specific tasks based on current EF models could thus renew the exploration of the continuum hypothesis. This paper will propose a research program aiming at: (1) clarifying the extent of executive dysfunctions in KS by tasks focusing on specific EF subcomponents; (2) determining the differential EF deficits in ADS and KS; (3) exploring EF-memory interactions in KS with innovative tasks. At the fundamental level, this exploration will test the continuum hypothesis beyond memory. At the clinical level, it will propose new rehabilitation tools focusing on the EF specifically impaired in KS.

Impairments in Episodic-Autobiographical Memory and Emotional and Social Information Processing in CADASIL during Mid-Adulthood

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) - is the most common genetic source of vascular dementia in adults, being caused by a mutation in NOTCH3 gene. Spontaneous de novo mutations may occur, but their frequency is largely unknown. Ischemic strokes and cognitive impairments are the most frequent manifestations, but seizures affect up to 10% of the patients. Herein, we describe a 47-year-old male scholar with a genetically confirmed diagnosis of CADASIL (Arg133Cys mutation in the NOTCH3 gene) and a seemingly negative family history of CADASIL illness, who was investigated with a comprehensive neuropsychological testing battery and neuroimaging methods. The patient demonstrated on one hand severe and accelerated deteriorations in multiple cognitive domains such as concentration, long-term memory (including the episodic-autobiographical memory domain), problem solving, cognitive flexibility and planning, affect recognition, discrimination and matching, and social cognition (theory of mind). Some of these impairments were even captured by abbreviated instruments for investigating suspicion of dementia. On the other hand the patient still possessed high crystallized (verbal) intelligence and a capacity to put forth a façade of well-preserved intellectual functioning. Although no definite conclusions can be drawn from a single case study, our findings point to the presence of additional cognitive changes in CADASIL in middle adulthood, in particular to impairments in the episodic-autobiographical memory domain and social information processing (e.g., social cognition). Whether these identified impairments are related to the patient's specific phenotype or to an ascertainment bias (e.g., a paucity of studies investigating these cognitive functions) requires elucidation by larger scale research.

Flashbulb memories in patients with temporal lobe epilepsy

PURPOSE

Flashbulb memories (FMs) are vivid and stable autobiographical memories associated with learning surprising news of high emotional impact. Patients with temporal lobe epilepsy (TLE) can have autobiographical memory deficits. This is the first investigation of FMs in TLE applying a consistency measure of FM quality controlling for confabulation.

METHOD

A sample of 12 patients with TLE and a matched group of 15 healthy controls (HCs) were tested on an FM test including a retest procedure. Scores of FM consistency were obtained by comparing answers across both testing occasions.

RESULTS

In patients with TLE, FM consistency scores were significantly lower than in HCs. Exploratory subgroup analyses revealed FM deficits in both patients with left TLE and patients with right TLE compared with HCs.

CONCLUSION

The present study indicates that the FMs of patients with TLE are less consistent than those of healthy control subjects. Future investigations with larger samples are desirable, especially regarding separate analyses of patients with left TLE and patients with right TLE.

Social cognition in a case of amnesia with neurodevelopmental mechanisms

Episodic-autobiographical memory (EAM) is considered to emerge gradually in concert with the development of other cognitive abilities (such as executive functions, personal semantic knowledge, emotional knowledge, theory of mind (ToM) functions, language, and working memory). On the brain level its emergence is accompanied by structural and functional reorganization of different components of the so-called EAM network. This network includes the hippocampal formation, which is viewed as being vital for the acquisition of memories of personal events for long-term storage. Developmental studies have emphasized socio-cultural-linguistic mechanisms that may be unique to the development of EAM. Furthermore it was hypothesized that one of the main functions of EAM is the social one. In the research field, the link between EAM and social cognition remains however debated. Herein we aim to bring new insights into the relation between EAM and social information processing (including social cognition) by describing a young adult patient with amnesia with neurodevelopmental mechanisms due to perinatal complications accompanied by hypoxia. The patient was investigated medically, psychiatrically, and with neuropsychological and neuroimaging methods. Structural high resolution magnetic resonance imaging revealed significant bilateral hippocampal atrophy as well as indices for degeneration in the amygdalae, basal ganglia, and thalamus, when a less conservative threshold was applied. In addition to extensive memory investigations and testing other (non-social) cognitive functions, we employed a broad range of tests that assessed social information processing (social perception, social cognition, social regulation). Our results point to both preserved (empathy, core ToM functions, visual affect selection, and discrimination, affective prosody discrimination) and impaired domains of social information processing (incongruent affective prosody processing, complex social judgments). They support proposals for a role of the hippocampal formation in processing more complex social information that likely requires multimodal relational handling.

Memory and self-neuroscientific landscapes

Relations between memory and the self are framed from a number of perspectives-developmental aspects, forms of memory, interrelations between memory and the brain, and interactions between the environment and memory. The self is seen as dividable into more rudimentary and more advanced aspects. Special emphasis is laid on memory systems and within them on episodic autobiographical memory which is seen as a pure human form of memory that is dependent on a proper ontogenetic development and shaped by the social environment, including culture. Self and episodic autobiographical memory are seen as interlocked in their development and later manifestation. Aside from content-based aspects of memory, time-based aspects are seen along two lines-the division between short-term and long-term memory and anterograde-future-oriented-and retrograde-past-oriented memory. The state dependency of episodic autobiographical is stressed and implications of it-for example, with respect to the occurrence of false memories and forensic aspects-are outlined. For the brain level, structural networks for encoding, consolidation, storage, and retrieval are discussed both by referring to patient data and to data obtained in normal participants with functional brain imaging methods. It is elaborated why descriptions from patients with functional or dissociative amnesia are particularly apt to demonstrate the facets in which memory, self, and personal temporality are interwoven.

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.

Towards solving the riddle of forgetting in functional amnesia: recent advances and current opinions

Remembering the past is a core feature of human beings, enabling them to maintain a sense of wholeness and identity and preparing them for the demands of the future. Forgetting operates in a dynamic neural connection with remembering, allowing the elimination of unnecessary or irrelevant information overload and decreasing interference. Stress and traumatic experiences could affect this connection, resulting in memory disturbances, such as functional amnesia. An overview of clinical, epidemiological, neuropsychological, and neurobiological aspects of functional amnesia is presented, by preponderantly resorting to own data from patients with functional amnesia. Patients were investigated medically, neuropsychologically, and neuroradiologically. A detailed report of a new case is included to illustrate the challenges posed by making an accurate differential diagnosis of functional amnesia, a condition that may encroach on the boundaries between psychiatry and neurology. Several mechanisms may play a role in "forgetting" in functional amnesia, such as retrieval impairments, consolidating defects, motivated forgetting, deficits in binding and reassembling details of the past, deficits in establishing a first person autonoetic connection with personal events, and loss of information. In a substantial number of patients, we observed a synchronization abnormality between a frontal lobe system, important for autonoetic consciousness, and a temporo-amygdalar system, important for evaluation and emotions, which provides empirical support for an underlying mechanism of dissociation (a failure of integration between cognition and emotion). This observation suggests a mnestic blockade in functional amnesia that is triggered by psychological or environmental stress and is underpinned by a stress hormone mediated synchronization abnormality during retrieval between processing of affect-laden events and fact-processing.

Amnesic disorders

Memory disturbances frequently occur after brain damage, but can be associated with psychiatric illnesses as well. Amnesia--the most severe form of memory impairment--has several variants, including anterograde and retrograde amnesia, material-specific and modality-specific amnesia, and transient global amnesia. We searched databases to obtain an overview of amnesia research from the past 5 years. Research into amnesia has increased exponentially, probably because of the availability of modern brain-imaging techniques. In line with the view that memory is not a unity but is organised into several systems, amnesia is described as a multifaceted disease with a frequently poor prognosis.

Function and dysfunction of prefrontal brain circuitry in alcoholic Korsakoff's syndrome

The signature symptom of alcohol-induced persisting amnestic disorder, more commonly referred to as alcoholic Korsakoff's syndrome (KS), is anterograde amnesia, or memory loss for recent events, and until the mid 20th Century, the putative brain damage was considered to be in diencephalic and medial temporal lobe structures. Overall intelligence, as measured by standardized IQ tests, usually remains intact. Preservation of IQ occurs because memories formed before the onset of prolonged heavy drinking--the types of information and abilities tapped by intelligence tests--remain relatively well preserved compared with memories recently acquired. However, clinical and experimental evidence has shown that neurobehavioral dysfunction in alcoholic patients with KS does include nonmnemonic abilities, and further brain damage involves extensive frontal and limbic circuitries. Among the abnormalities are confabulation, disruption of elements of executive functioning and cognitive control, and emotional impairments. Here, we discuss the relationship between neurobehavioral impairments in KS and alcoholism-related brain damage. More specifically, we examine the role of damage to prefrontal brain systems in the neuropsychological profile of alcoholic KS.

Anterograde episodic memory in Korsakoff syndrome

A profound anterograde memory deficit for information, regardless of the nature of the material, is the hallmark of Korsakoff syndrome, an amnesic condition resulting from severe thiamine (vitamin B1) deficiency. Since the late nineteenth century when the Russian physician, S. S. Korsakoff, initially described this syndrome associated with "polyneuropathy," the observed global amnesia has been a primary focus of neuroscience and neuropsychology. In this review we highlight the historical studies that examined anterograde episodic memory processes in KS, present a timeline and evidence supporting the myriad theories proffered to account for this memory dysfunction, and summarize what is known about the neuroanatomical correlates and neural systems presumed affected in KS. Rigorous study of KS amnesia and associated memory disorders of other etiologies provide evidence for distinct mnemonic component processes and neural networks imperative for normal declarative and nondeclarative memory abilities and for mnemonic processes spared in KS, from whence emerged the appreciation that memory is not a unitary function. Debate continues regarding the qualitative and quantitative differences between KS and other amnesias and what brain regions and neural pathways are necessary and sufficient to produce KS amnesia.

Remote memory function and dysfunction in Korsakoff's syndrome

Korsakoff's syndrome (KS) is a pervasive disorder of memory characterized by both anterograde and retrograde amnesia. Although retrograde memory impairment in KS has been less frequently studied, the status of remote memory in KS has been tested across a number of different tasks that measure knowledge of public information (e.g., famous faces/news events), general semantic information (e.g., vocabulary words), personal semantic information (e.g., facts about oneself), and autobiographical events (e.g., events from one's personal past). In each of these domains, Korsakoff patients demonstrate remote memory impairments that can extend back many years or decades. In addition, a majority of studies report that the extensive remote memory impairment in KS is temporally graded, with relative preservation of memories from childhood and early adulthood. The current paper reviews published experimental studies of remote memory in KS, with particular attention paid to (a) the selectivity of the deficit with respect to the age of the memory and (b) the relationship of memory impairment to underlying neuropathology. We discuss the significance of the reported pattern and extent of remote memory impairment with respect to theories about the nature of the underlying cognitive deficits in KS.

Alcohol-Related Cognitive and Affective Impairments in a Sample of Long-Term Care Residents

We provide a detailed exploration of cognitive and affective impairments in a small group (N = 8) of detoxified chronic alcohol abusers living in a long-term care facility. The findings of our cognitive test battery suggest impairment in executive functions with reduced mental flexibility, deficits in cognitive estimation, and deteriorated memory performances. The results of our affective tests demonstrate a reduced capability to correctly recognize emotional facial expressions and an impaired processing of affective verbal material included in our sample. Given the present findings, we conclude the necessity of developing local clinical pathways for the management of severely deteriorated alcohol-related brain damaged individuals by elaborating specific lifelong 24 h care programs focusing on sociotherapeutic support.