Network Localization of Spontaneous Confabulation.

OBJECTIVE: Spontaneous confabulation is a symptom in which false memories are conveyed by the patient as true. The purpose of the study was to identify the neuroanatomical substrate of this complex symptom and evaluate the relationship to related symptoms, such as delusions and amnesia. METHODS: Twenty-five lesion locations associated with spontaneous confabulation were identified in a systematic literature search. The network of brain regions functionally connected to each lesion location was identified with a large connectome database (N=1,000) and compared with networks derived from lesions associated with nonspecific (i.e., variable) symptoms (N=135), delusions (N=32), or amnesia (N=53). RESULTS: Lesions associated with spontaneous confabulation occurred in multiple brain locations, but they were all part of a single functionally connected brain network. Specifically, 100% of lesions were connected to the mammillary bodies (familywise error rate [FWE]-corrected p<0.05). This connectivity was specific for lesions associated with confabulation compared with lesions associated with nonspecific symptoms or delusions (FWE-corrected p<0.05). Lesions associated with confabulation were more connected to the orbitofrontal cortex than those associated with amnesia (FWE-corrected p<0.05). CONCLUSIONS: Spontaneous confabulation maps to a common functionally connected brain network that partially overlaps, but is distinct from, networks associated with delusions or amnesia. These findings lend new insight into the neuroanatomical bases of spontaneous confabulation.

Factors affecting the forced confabulation effect: a meta-analysis of laboratory studies.

During police investigations, interviewees are sometimes forced to confabulate a response to questions for which they don't know the answer. In this registered report, we conducted a three-level meta-analysis to examine whether forcing people to confabulate an answer to these questions can lead to false memories for the confabulated details and/or events (i.e., forced confabulation effect). Results showed that forced confabulation indeed led to the production of false memories. Qualitative reviews of studies suggested that the forced confabulation effect is enhanced after receiving confirmatory feedback. Moreover, we found evidence that longer delays between the forced confabulation phase and the final memory task are necessary to observe the forced confabulation effect for entire events. However, caution is needed when interpreting the forced confabulation effect. Specifically, our moderator analyses revealed that voluntarily produced confabulation led to more false memories than forced confabulation. Also, our exploratory analysis indicated that the forced confabulation effect was mainly observed in within-subject designs. Taken together, our meta-analysis supports the notion that forcing participants to confabulate can lead them to later report such confabulations as part of the truth. Nonetheless, caution is warranted because this effect might be due to the introduction of misinformation through asking unanswerable questions.

"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.

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.

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.

Adopting a fictitious autobiography: fabrication inflation or deflation?

In the present experiment, we examined whether adopting a fictitious biography would make participants believe in this autobiography. Participants were split up into two conditions: forced confabulation condition and control condition. The forced confabulation condition received a snippet with the fake biography and had to adopt it through several methods (i.e., method acting, journaling, and convincing experimenters in an interview) over an extended period of time. The control condition was told that they partook in an experiment about personal childhood memories. Before, during and after lying participants completed four Life Event Inventories (LEI). Results revealed that after coming forward with the truth participants did not increase nor decrease their belief for the lied about events. Additionally, even after a one-year delay, we found no evidence for either effect. Our findings suggest that more extreme forms of fabrication do not make people believe in their lies.

Screening for confabulations with the confabulation screen.

The objective of this work is to devise and validate a sensitive and specific test for confabulatory impairment. We conceived a screening test for confabulation, the Confabulation Screen (CS), a brief test using 10 questions of episodic memory (EM), where confabulators most frequently confabulate. It was postulated that the CS would predict confabulations not only in EM, but also in the other subordinate structures of personal temporality, namely the present and the future. Thirty confabulating amnesic patients of various aetiologies and 97 normal controls entered the study. Participants were administered the CS and the Confabulation Battery (Dalla Barba, G., & Decaix, C. (2009). "Do you remeber what you did on March 13 1985?" A case study of confabulatory hypermnesia. Cortex, 45(5), 566-574). Confabulations in the CS positively and significantly correlated with confabulations in personal temporality domains of the CB, namely EM, orientation in time and place and episodic plans. Conversely, as expected, they did not correlate with confabulations in impersonal temporality domains of the CB. Consistent with results of previous studies, the most frequently observed type of confabulation in the CS was Habits Confabulation. The CS had high construct validity and good discriminative validity in terms of sensitivity and specificity. Cut-off scores for clinical and research purposes are proposed. The CS provides efficient and valid screening for confabulatory impairment.

Anomalies of Autobiographical Memory.

OBJECTIVES: In this paper, I review three 'anomalies' or disorders in autobiographical memory: neurological retrograde amnesia (RA), spontaneous confabulation, and psychogenic amnesia. METHODS: Existing theories are reviewed, their limitations considered, some of my own empirical findings briefly described, and possible interpretations proposed and interspersed with illustrative case-reports. RESULTS: In RA, there may be an important retrieval component to the deficit, and factors at encoding may give rise to the relative preservation of early memories (and the reminiscence bump) which manifests as a temporal gradient. Spontaneous confabulation appears to be associated with a damaged 'filter' in orbitofrontal and ventromedial frontal regions. Consistent with this, an empirical study has shown that both the initial severity of confabulation and its subsequent decline are associated with changes in the executive function (especially in cognitive estimate errors) and inversely with the quantity of accurate autobiographical memories retrieved. Psychogenic amnesia can be 'global' or 'situation-specific'. The former is associated with a precipitating stress, depressed mood, and (often) a past history of a transient neurological amnesia. In these circumstances, frontal control mechanisms can inhibit retrieval of autobiographical memories, and even the sense of 'self' (identity), while compromised medial temporal function prevents subsequent retrieval of what occurred during a 'fugue'. An empirical investigation of psychogenic amnesia and some recent imaging studies have provided findings consistent with this view. CONCLUSIONS: Taken together, these various observations point to the importance of frontal 'control' systems (in interaction with medial temporal/hippocampal systems) in the retrieval and, more particularly, the disrupted retrieval of 'old' memories.

The confabulation battery: Instructions and international data from normal participants.

Confabulation is an unusual sign in neurological and in neuropsychological pathologies. In this article we present an objective neuropsychological instrument, the Confabulation Battery (CB), which allows the quantifying and qualifying of different types of confabulations. The CB was administered to French and Italian normal participants. Data from the present study will allow clinicians and researchers, using the CB, to know how much and in which memory domains their confabulating patients confabulate compared to normal participants. We present international data, instructions and guidelines for the CB, a tool used in different ways worldwide. Not quantifying confabulations, namely not reporting how much and in which domain patients confabulate, can hardly lead to conclusions on the neurocognitive bases of this phenomenon. Following the instructions in this article, versions of the CB can be adapted in different languages and cultures. Quantification and qualification of confabulation is necessary and demanded in order to compare sensibly data from different research and clinical groups.

Different patterns of confabulation in left visuo-spatial neglect.

Confabulating patients produce statements and actions that are unintentionally incongruous to their history, background, present and future situation. Here we present the very unusual case of a patient with right hemisphere damage and signs of left visual neglect, who, when presented with visual stimuli, confabulated both for consciously undetected and for consciously detected left-sided details. Advanced anatomical investigation suggested a disconnection between the parietal and the temporal lobes in the right hemisphere. A disconnection between the ventral cortical visual stream and the dorsal fronto-parietal networks in the right hemisphere may contribute to confabulatory behaviour by restricting processing of left-sided stimuli to pre-conscious stages in the ventral visual stream.

Behavioral evidence suggestive of frontal lobe pathology in the amnesic H.M.

From the earliest published reports, Henry Gustav Molaison-who until his death in 2008 was known simply by his initials H.M.-was characterized as having a profound anterograde amnesia subsequent to mid temporal lobe resection, and that this amnestic condition was uncomplicated by other cognitive or behavioral impairments. Post-mortem neuropathological examination has detected-in addition to the expected temporal lobe lesions-previously unreported frontal lobe and white matter pathology, inviting questions concerning the behavioral and cognitive consequences that might result from such lesions. The purpose of this article is to recount published descriptions of a range of anomalous behaviors by H.M. that can not be explained by the memory impairments typically associated with anterograde amnesia, to counter previous claims that these behaviors are attributable to amygdalar damage, and to advance the interpretation that these behaviors are instead consistent with well-documented effects of frontal lobe pathology. Transcripts of interviews with H.M. which feature disjointed, often contradictory, and arguably confabulatory responses are presented in support of this argument.

Factors influencing confabulation in Japanese patients with Alzheimer's disease.

BACKGROUND: Confabulations are often observed in patients with Alzheimer's disease (AD) and can increase family caregivers' burdens. Previous studies have focused on the relationship between confabulation and cognitive ability. However, few studies have investigated the association between confabulation and familial factors. Here, we aimed to examine whether confabulation relates to familial factors, such as the level of family caregivers' expressed emotion or the level of functioning of the family. METHODS: Twenty-seven outpatients with AD and their family caregivers participated in this study. We examined confabulations about episodic memory, semantic memory, and future planning using the Modified Confabulation Battery (MCB). We investigated correlations between scores on the MCB and scores on the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), Family Attitude Scale (FAS), and the Family Adaptability and Cohesion Evaluation Scale. Multiple regression analyses were performed using the total scores on the MCB and domain-specific scores on the MCB as dependent variables, and the scores on the MMSE, GDS, and FAS as independent variables. RESULTS: MCB scores were positively related to FAS scores (P < 0.01) and negatively to GDS scores (P < 0.05), but not to MMSE scores. Regarding the three domains the MCB measured, confabulation about episodic memory and future planning showed a positive relationship with FAS scores. CONCLUSIONS: Family attitude was the factor most related to confabulation in our study. Patients with AD may attempt to avoid confronting family caregivers' high emotional expression through confabulation, or confabulation itself might result in high emotional expression among family caregivers. Psychoeducational or therapeutic approaches for family caregivers might reduce confabulation in patients with AD.

Memory, Decision-Making, and the Ventromedial Prefrontal Cortex (vmPFC): The Roles of Subcallosal and Posterior Orbitofrontal Cortices in Monitoring and Control Processes.

The ventromedial prefrontal cortex (vmPFC) prominently and separately features in neurobiological models of decision-making (e.g., value-encoding) and of memory (e.g., automatic veracity-monitoring). Recent decision-making models propose value judgments that inherently comprise of second-order confidence estimates. These demonstrate quadratic relationships with first-order judgments and are automatically encoded in vmPFC activity. Memory studies use Quantity-Accuracy Profiles to capture similar first-order and second-order meta-mnemonic processes, suggesting convergence across domains. Patients with PFC damage answered general knowledge questionnaires under 2 conditions. During forced report, they chose an answer and rated the probability of it being correct (first-order "monitoring"). During free report, they could choose to volunteer or withhold their previous answers (second-order "control") to maximize performance. We found quadratic relationships between first-order and second-order meta-mnemonic processes; voxel-based lesion-symptom mapping demonstrated that vmPFC damage diminished that relationship. Furthermore, damage to subcallosal vmPFC was specifically associated with impaired monitoring and additional damage to posterior orbitofrontal cortex led to deficient control. In decision-making, these regions typically support valuation and choice, respectively. Persistent spontaneous confabulation (false memory production) confirmed the clinical relevance of these dissociations. Compared with patients with no confabulation history, patients who currently confabulate were impaired on both monitoring and control, whereas former confabulators demonstrated impaired monitoring but intact control.

"Cat-gras" delusion: a unique misidentification syndrome and a novel explanation.

ABSRACT Capgras syndrome is a distressing delusion found in a variety of neurological and psychiatric diseases where a patient believes that a family member, friend, or loved one has been replaced by an imposter. Patients recognize the physical resemblance of a familiar acquaintance but feel that the identity of that person is no longer the same. Here we describe a 73-year-old male with right posterior frontal and bilateral anterior-medial frontal damage from prior brain trauma with a similar delusion of an imposter replacing his pet cat. Misidentification syndromes for animals, as opposed to humans, have been rarely reported. Neuropsychological testing showed deficits in executive processing and memory retrieval with prominent intrusions and false positive responses. The delusional belief content in Capgras syndrome has been hypothesized to result from loss of an emotional or autonomic response to familiar stimuli, from theory of mind deficits, or from loss of self-environment distinctions. We instead propose that Capgras delusions result from a dysfunction in linking external stimuli with retrieved internal autobiographical memories pertaining to that object. This leads to an erroneously learned identity that persists as a specific delusional belief.

These two are different. Yes, they're the same: Choice blindness for facial identity.

We examined the manipulability of face identity judgements by combining a sorting task for unfamiliar faces with a standard test of choice blindness. In Experiment 1, 50 participants completed a sorting task and then justified grouping specific pairs of photos together or apart. On manipulated trials, the presented pairings were different from those the participants had actually produced. Detection rates for these identity manipulations were strikingly low (∼21%). Moreover, participants readily provided justifications for identity decisions that they had not made, typically referring to specific facial features. Experiment 2 was conducted along similar lines and confirmed that lower task difficulty and higher confidence in one's face identity judgements increase detection rates. We conclude that observers can easily be led to believe that they made identity judgements they did not make. As well as underscoring the fragility of unfamiliar face matching, our findings have implications for identity judgements in legal settings.

Different patterns of recollection impairment in confabulation reveal different disorders of consciousness: A multiple case study.

Recollection is used to refer to the active process of setting up retrieval cues, evaluating the outcome, and systematically working toward a representation of a past experience that we find acceptable. In this study we report on three patients showing different patterns of confabulation affecting recollection and consciousness differentially. All patients confabulated in the episodic past domain. However, whereas in one patient confabulation affected only recollection of events concerning his personal past, present and future, in another patient confabulation also affected recollection of impersonal knowledge. The third patient showed an intermediate pattern of confabulation, which affected selectively the retrieval of past information, both personal and impersonal. We suggest that our results are in favor of a fractionation of processes involved in recollection underling different disorders of consciousness.

'I ate too much so I must have been sad': Emotions as a confabulated reason for overeating.

BACKGROUND: Emotional eating (i.e., overeating in response to negative affect) is a commonly accepted explanation for eating behaviors that are not in line with personal eating-norms. However, the empirical evidence for a causal link between self-reported emotional eating and overeating is mixed. The present study tested an alternative hypothesis stating that high emotional eating scores are indicative of a susceptibility to use negative affect as a confabulated, post-hoc reason to explain overeating. METHODS: Female students (N = 46) participated in a 'taste-test' and came back to the lab a day later to receive feedback that they either ate too much (norm-violation condition) or an acceptable amount of food (control condition), whereafter emotional eating was assessed. Negative affect was measured several times throughout the study. RESULTS: In the norm-violation condition, participants with high emotional eating scores retrospectively rated their affect prior to eating as more negative than participants with low emotional eating scores. In the control condition, no effect of emotional score on affect ratings was found. DISCUSSION: For some individuals emotional eating scores may represent a tendency to retrospectively attribute overeating to negative affect. This could explain the lack of consistent findings for a link between self-reported emotional eating and overeating.

Schema representation in patients with ventromedial PFC lesions.

Human neuroimaging and animal studies have recently implicated the ventromedial prefrontal cortex (vmPFC) in memory schema, particularly in facilitating new encoding by existing schemas. In humans, the most conspicuous memory disorder following vmPFC damage is confabulation; strategic retrieval models suggest that aberrant schema activation or reinstatement plays a role in confabulation. This raises the possibility that beyond its role in schema-supported memory encoding, the vmPFC is also implicated in schema reinstatement itself. If that is the case, vmPFC lesions should lead to impaired schema-based operations, even on tasks that do not involve memory acquisition. To test this prediction, ten patients with vmPFC damage, four with present or prior confabulation, and a group of twelve matched healthy controls made speeded yes/no decisions as to whether words were closely related to a schema (a visit to the doctor). Ten minutes later, they repeated the task for a new schema (going to bed) with some words related to the first schema included as lures. Last, they rated the degree to which stimuli were related to the second schema. All four vmPFC patients with present or prior confabulation were impaired in rejecting lures and in classifying stimulus belongingness to the schema, even when they were not lures. Nonconfabulating patients performed comparably to healthy adults with high accuracy, comparable reaction times, and similar ratings. These results show for the first time that damage to the human vmPFC, when associated with confabulation, leads to deficient schema reinstatement, which is likely a prerequisite for schema-mediated memory integration.

Implicit bias, confabulation, and epistemic innocence.

In this paper I explore the nature of confabulatory explanations of action guided by implicit bias. I claim that such explanations can have significant epistemic benefits in spite of their obvious epistemic costs, and that such benefits are not otherwise obtainable by the subject at the time at which the explanation is offered. I start by outlining the kinds of cases I have in mind, before characterising the phenomenon of confabulation by focusing on a few common features. Then I introduce the notion of epistemic innocence to capture the epistemic status of those cognitions which have both obvious epistemic faults and some significant epistemic benefit. A cognition is epistemically innocent if it delivers some epistemic benefit to the subject which would not be attainable otherwise because alternative (less epistemically faulty) cognitions that could deliver the same benefit are unavailable to the subject at that time. I ask whether confabulatory explanations of actions guided by implicit bias have epistemic benefits and whether there are genuine alternatives to forming a confabulatory explanation in the circumstances in which subjects confabulate. On the basis of my analysis of confabulatory explanations of actions guided by implicit bias, I argue that such explanations have the potential for epistemic innocence. I conclude that epistemic evaluation of confabulatory explanations of action guided by implicit bias ought to tell a richer story, one which takes into account the context in which the explanation occurs.

Confabulations in schizophrenia.

INTRODUCTION: Current theories of confabulation are based primarily on the observation of neurological patients. The present paper evaluates these theories based on evidence from schizophrenia. Schizophrenia is unique in that it presents with a pathophysiology which differs from that of other neuropsychiatric conditions, and yet the candidate's deficits that various theories of confabulation implicate are often simultaneously present in schizophrenia. METHODS: A selective review of literature on schizophrenic and neurological confabulations was undertaken. RESULTS: Schizophrenic confabulation differs from neurological confabulation in terms of its characteristic features and association with symptoms, cognition and linguistic functions. Current evidence also suggests that confabulation may be conceptualized as a special class of delusions pertaining to memory phenomena. CONCLUSIONS: Schizophrenia presents with confabulations that cannot be fully accounted for by the existing theories. It also presents with confabulations with unique features, which have different cognitive correlates and relation to other symptoms of the condition.