The left hemisphere interpreter refers to a function in the left hemisphere of the brain that search for and produce causal explanations for events, behaviours and feelings, even though no such apparent pattern exists between them. Confabulation is said to occur when a person presents or acts on obviously false information, despite being aware that they are false. People who confabulate also tend to defend their confabulations even when they are presented with counterevidence. Research related to these two areas seems to deal with the same phenomenon, namely the human tendency to infer explanations for events, even if the explanations have no actual bearing in reality. Despite this, research on the left hemisphere interpreter has progressed relatively independently from research related to the concept of confabulation. This thesis has therefore aimed at reviewing each area and comparing them in a search for common relations. What has been found as a common theme is the emphasis they both place on the potentially underlying function of the interpreter and confabulation. Many researchers across the two fields stress the adaptive and vital function of keeping the brain free from both contradiction and unpredictability, and propose that this function is served by confabulations and the left hemisphere interpreter. This finding may provide a possible opening for collaboration across the fields, and for the continued understanding of these exciting and perplexing phenomena.

Diese Arbeit verbindet zwei Publikationen, die sich mit beeinträchtigter Krankheitseinsicht (Anosognosie) bei Patienten mit Alzheimer-Demenz (AD) befassen, sowie mit den Erfassungsmethoden und der Frage, ob Anosognosie bestimmte Bereiche besonders betrifft. Die erste Veröffentlichung stellt die Ergebnisse einer systematischen Literaturübersicht zum Forschungsstand zu Anosognosie bei AD und zu den verschiedenen Erfassungsmethoden für die Krankheitseinsicht von AD-Patienten dar. In der zweiten Publikation sind die Ergebnisse einer empirischen Studie zur Anosognosie bei Patienten mit leichter AD veröffentlicht. Die Ergebnisse dieser Studie weisen zum einen darauf hin, dass die drei Erfassungsmethoden für Anosognosie (klinisches Urteil, Diskrepanz zwischen Selbst- und Fremdeinschätzung, Diskrepanz zwischen Selbsteinschätzung und Testleistung) teils unterschiedliche Facetten der Selbsteinschätzung abbilden. Zum anderen deuten die Befunde darauf hin, dass Unterschiede zwischen den Diskrepanzen zwischen Selbst- und Fremdeinschätzung in verschiedenen Symptombereichen maßgeblich auf unterschiedliche Grade der Beeinträchtigung zurückzuführen sind und nicht Ausdruck einer domänenspezifischen Ausprägung der Einsichtsfähigkeit bei AD-Patienten sind. Diese Studienergebnisse werden in der vorliegenden Arbeit im Zusammenhang mit Erklärungsansätzen für Anosognosie bei AD diskutiert.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from PDF title page (viewed Sept. 23, 2009). Additional advisors: Karlene K. Ball, H. Randall Griffith, Daniel C. Marson, Sylvie Mrug, David E. Vance. Includes bibliographical references (p. 59-80).

La conscience des troubles a un impact important sur la vie quotidienne des personnesatteintes de démence et de leurs proches. Bien qu’il s’agisse d’un élément problématique dans leparcours de soin, un consensus autour des facteurs responsables et de la variation de saprésentation n’a pas pu être établi. Cette thèse cherche à identifier les caractéristiques et lesmécanismes de la conscience des troubles en lien avec la symptomatologie démentielle : lestroubles cognitifs, affectifs et d’autonomie. L’anosognosie est évaluée spécifiquement grâce à laméthode des écarts entre des mesures issues d’auto-évaluations (prédictions de performances etestimations personnelles) et celles issues d’hétéro-évaluations (tests objectifs et proches-aidants).Une première étude avait pour objectif d’expliciter la nature de l’anosognosie cognitive et savariabilité selon le stade de la maladie d’Alzheimer. L’anosognosie pour le fonctionnementcognitif global ainsi que pour tous les processus évalués au travers de la Dementia Rating Scale(DRS) augmente avec la sévérité de la démence. A contrario, l’anosognosie des troubles mnésiquesne suit pas la dégradation cognitive, créant un clivage avec la conscience des troubles des autresprocessus cognitifs. Ces résultats confirment l’hétérogénéité de l’anosognosie et sa variabilitéselon le stade de la maladie. Des outils objectivant des processus plus purs permettraient despécifier les liens entre troubles cognitifs et anosognosie ce que nous avons réalisé dans unedeuxième étude. Des facteurs cognitifs (tests neuropsychologiques) et non cognitifs (anxiété,indépendance fonctionnelle) sont corrélés significativement à tous les scores d’anosognosiecognitive. Chaque score d’anosognosie est prédit par un ensemble de variables qui lui estspécifique : trois scores par un modèle de régression purement cognitif et un score incluant desfacteurs cognitifs et non cognitifs. Nos résultats mettent en évidence le rôle majeur d’un déficitdysexécutif et l’implication de variables non cognitives, confirmant le caractère multifactoriel del’anosognosie. Enfin, une troisième étude investiguait l’anosognosie concernant la perte d’indépendancefonctionnelle via l’échelle ADL. L’intensité de l’anosognosie était significativement comparableentre les groupes vivant à domicile et en EHPAD. La sévérité des troubles cognitifs n’expliquepas directement la présence de cette forme d’anosognosie. De plus, les sous-dimensions del’échelle ADL sont affectées différemment par l’anosognosie, certaines étant préservées etd’autres non. Ces résultats soutiennent l’idée que l’anosognosie est un phénomène à la foismultidimensionnel qui existe hors de la sphère cognitive, et hétérogène qui varie d’une sousdimensionà une autre.Ces travaux vont dans le sens d’une hétérogénéité de l’anosognosie et ce quels que soientl’objet de conscience ou les stades de la démence considérés. L’influence de variables cognitiveset non cognitives suggère une étude plus systématique de leurs rôles respectifs et la nécessitéd’étudier l’anosognosie dans une perspective exhaustive. La conception en tant que phénomènede la conscience de soi en neurologie sera questionnée, puis préférée à celle de symptôme, autravers d’une nouvelle modélisation. Envisager l’anosognosie comme un déficit d’une partie duSelf offre des pistes de remédiation grâce aux éléments non altérés du Self mais également lapossibilité de considérer chaque personne comme un être conscient et en capacité d’agir face à sa maladie. / Awareness of deficits has a significant impact on the daily lives of people with dementia andtheir relatives. While it represents a problematic element in patients’ care path,there is still noconsensus as to its etiological factors and the variability in its presentation. This thesis aims toidentify the cognitive, affective and autonomic mechanisms associated with disorder awarenessimpairment in dementia. This thesis seeks to identify the characteristics and disorder awarenessmechanisms related to the dementia symptomatology: cognitive, affective and autonomicdisorders. Anosognosia is evaluated using the discrepancies method between measurements takenfrom self-assessment (performance predictions and personal estimates) and hetero-evaluationsscales (objective and caregiver tests).A first study aimed to explain the nature of cognitive anosognosia and its variability accordingto Alzheimer's disease stage. Anosognosia for overall cognitive functioning as well as for allprocesses evaluated through the Dementia Rating Scale (DRS) increases with the severity ofdementia. Conversely, anosognosia of memory disorders did not follow cognitive degradation,creating a cleavage with the anosognosia of other cognitive processes. These results confirm theheterogeneity of anosognosia and its variability according to the stage of the disease.The links between cognitive disorders and anosognosia were then quantified in a secondstudy. Cognitive (neuropsychological tests) and non-cognitive factors (anxiety, functionalindependence) turned out to be significantly correlated with all cognitive anosognosia scores.Each anosognosia score was predicted by a specific set of variables: three scores by a purelycognitive regression model and one score by cognitive and non-cognitive factors. Our resultshighlight the major role of dysexecutive deficits and the involvement of non-cognitive variables,confirming anosognosia’s multifactorial character. Finally, a third study investigated anosognosia for the loss of functional independence usingthe ADL scale. The intensity of anosognosia was significantly comparable between the groupsliving at home and in nursing homes. The severity of cognitive disorders did not directly explainthe presence of this form of anosognosia. Additionally, the ADL scale's sub-dimensions weredifferentially affected by anosognosia, some being preserved while others were not. These resultssupport the idea that anosognosia is a multidimensional and heterogeneous phenomenon thatexists outside of the cognitive sphere, and which varies from one subdimension to another.This work suggests that anosognosia is a heterogeneous construct irrespective of the object ofconsciousness or stages of dementia. The influence of cognitive and non-cognitive variablespoints to the need for a more systematic study of their respective roles and the need to studyanosognosia from comprehensive perspective. Anosognosia as self-awareness’ phenomenon inneurology is discussed and a new modelling strategy is proposed to assess its advantages over asymptom-based framework. Considering anosognosia as a deficit of parts of the Self points topossible remedial paths through the unimpaired elements of the Self but also to the possibility ofconsidering each person as a conscious being capable of acting in the face of his disease.

Yes / People living with dementia vary in awareness of their abilities. We explored awareness of the condition and diagnosis in people with mild-to-moderate dementia, and how this relates to quality of life, well-being, life satisfaction, and caregiver stress. This study was a cross-sectional exploratory analysis of data from the IDEAL cohort, which recruited people with dementia living at home and available caregivers from 29 research sites in Great Britain. Our study included 917 people with mild-to-moderate dementia and 755 carers. Low and high awareness groups were derived from self-reported responses to a dementia representation measure. Logistic regression was used to explore predictors of awareness of condition and diagnosis using demographic, cognitive, functional and psychological measures, and the relationship with quality of life, well-being and life satisfaction (‘living well’), and caregiver stress. There were 83 people with low awareness of their condition. The remaining 834 people showed some awareness and 103 of these had high awareness of their condition and diagnosis. Psychosocial factors were stronger predictors of awareness than cognitive and functional ability. Those with higher awareness reported lower mood, and lower scores on indices of living well as well as lower optimism, self-efficacy and self-esteem. Low awareness was more likely in those aged 80y and above, and living in more socially deprived areas. No relationship was seen between caregiver stress and awareness. Awareness of the condition and diagnosis varies in people with mild-to-moderate dementia and is relevant to the capability to live well. Awareness should be considered in person-centered clinical care.

[pt] A falta de consciência dos déficits cognitivos ou da doença (ou anosognosia) é uma característica frequente na doença de Alzheimer (DA). No entanto, existe uma variabilidade na apresentação e na severidade da anosognosia em pacientes com DA. Com base no Cognitive Awareness Model (CAM), esta tese tem como objetivo explorar experimentalmente dois fatores que podem possivelmente influenciar a consciência das habilidades cognitivas, a saber, o estado de humor atual e a perspectiva através da qual a informação é apresentada, na DA. A primeira parte desta tese explora o impacto do estado de humor na consciência dos déficits. Como sugerido no CAM que vieses emocionais podem influenciar o acesso para memórias pessoais, consequentemente levando a anosognosia, uma revisão sistemática da literatura foi conduzida para entender melhor o efeito de memória congruente ao humor em adultos saudáveis (Article 1). Em seguida, apresentamos um estudo experimental investigando esta hipótese na DA (Article 2). Nesse estudo, estados de humor negativos e neutros foram experimentalmente induzidos usando quatro tarefas de Success-Failure Manipulation (SFM), duas tarefas com base no tempo de reação e duas com base na memória. Os resultados mostraram um aumento da consciência dos sintomas após a indução de humor negativo, mas somente quando a tarefa usada no SFM era com base na memória. A segunda parte deste trabalho investiga se a perspectiva através qual a informação é apresentada (auto vs. outro) influencia as habilidades metacognitivas de pacientes com DA. De fato, uma revisão da literatura destacou que estudos explorando o impacto da tomada de perspectiva na metacognição com diferentes populações neurológicas e psiquiátricas mostraram que os pacientes são capazes de reconhecer déficits em outros, apesar da apresentar uma falta de consciência das suas próprias dificuldades (Article 3). Em seguida, um estudo experimental foi conduzido pedindo para pacientes com DA e controles avaliar o seu próprio desempenho em quatro diferentes tarefas, assim como avaliar o desempenho de uma pessoa conhecida (cuidador/esposo/amigo) (Article 4). Nossos resultados destacam que, em geral ambos os grupos superestimaram mais quando avaliavam o desempenho de uma pessoa conhecida. No entanto, pacientes com DA tenderam a superestimar mais o desempenho em comparação com controles, mas somente no experimento envolvendo tarefas de memória. Em resumo, os resultados destes estudos dão suporte experimental a três aspectos sugeridos pelo CAM como fatores influenciando a consciência de déficits. Em primeiro lugar, as achados sobre a relação entre humor e consciência apoiam à ideia de vieses emocionais na memória como uma explicação parcial para anosognosia. Em segundo lugar, os resultados mostrando que os pacientes com DA avaliam o próprio desempenho de uma forma diferente em comparação a avaliação do desempenho de uma pessoa conhecida apoiam à inclusão de diferentes registros de memória para informações pessoais e para informações sobre os outros na versão reformulada do CAM. Em terceiro lugar, nossos achados mostrando diferenças nos resultados dependendo do tipo de tarefa usado no SFM (tempo de reação vs. memória) reforçam o conceito de uma consciência dos déficits como sendo multidimensional, conceito que está na base do aspecto modular do CAM. / [en] Lack of awareness about cognitive deficits or illness, also named anosognosia, is a common feature of Alzheimer s disease (AD). However, there is variability in the presentation and severity of anosognosia in patients with AD. Based on the Cognitive Awareness Model (CAM), this thesis aims to explore experimentally two factors which could possibly influence the awareness of cognitive abilities in AD, namely current mood state and the perspective through which the information is presented. The first section of this thesis explores the impact of mood state on awareness of deficits. As it has been suggested in the CAM that emotional biases could influence the access to personal memories, consequently leading to anosognosia, a systematic literature review was conducted to understand better the mood-congruent memory effect in healthy adults (Article 1). Then, we present an experimental study investigating this hypothesis in AD (Article 2). In this study, negative and neutral mood states were experimentally induced using four Success-Failure Manipulation (SFM) tasks, two based on reaction time tasks and the other on memory tasks. The results showed an improvement of awareness of symptoms after negative mood induction, but only when the task used in the SFM was memory-based. The second section of this work investigates if the perspective through which the information is presented (self vs. other) has an influence on metacognitive abilities of patients with AD. Indeed, a literature review highlighted that studies exploring the impact of perspective taking on metacognition with different neurologic and psychiatric populations showed that patients are able to recognize deficits in others, despite lack of awareness of their own difficulties (Article 3). Then, an experimental study was conducted by asking AD patients and controls to evaluate their own performance on four different tasks, as well as the performance of a well-known person (caregiver/spouse/friend) (Article 4). Our findings highlight that overall both groups made higher overestimation when evaluating the performance of a well-known person. However, AD patients tended to overestimate more the performance compared to controls but only in the memory experiment. In summary, results of these studies give experimental support to three aspects suggested by the CAM as factors influencing awareness of deficits. First, the findings on the relationship between mood and awareness support the idea of emotional biases in memory as a partial explanation for anosognosia. Second, the results showing that AD patients appraise the evaluation of selfperformance differently than the evaluation of a well-known person s performance support the inclusion of different memory records for self- and otherinformation in the reformulated version of the CAM. Third, by presenting differences in results depending on the type of task used in the SFM (reaction time vs. memory), our findings reinforce the concept that awareness is multidimensional, on which is based the modular aspect of the CAM.

For many historians, sociologists, and anthropologists of medicine, "disease" and "illness" are not equivalent. Whereas "disease" denotes the physician's ostensibly objective criteria, "illness" emphasizes the patient's subjective experience. This dissertation examines that distinction precisely at a point where it breaks down, in the history of a diagnosis called "anosognosia," also known as the denial of illness. / History of Science

Diese Arbeit verbindet zwei Publikationen, die sich mit beeinträchtigter Krankheitseinsicht (Anosognosie) bei Patienten mit Alzheimer-Demenz (AD) befassen, sowie mit den Erfassungsmethoden und der Frage, ob Anosognosie bestimmte Bereiche besonders betrifft. Die erste Veröffentlichung stellt die Ergebnisse einer systematischen Literaturübersicht zum Forschungsstand zu Anosognosie bei AD und zu den verschiedenen Erfassungsmethoden für die Krankheitseinsicht von AD-Patienten dar. In der zweiten Publikation sind die Ergebnisse einer empirischen Studie zur Anosognosie bei Patienten mit leichter AD veröffentlicht. Die Ergebnisse dieser Studie weisen zum einen darauf hin, dass die drei Erfassungsmethoden für Anosognosie (klinisches Urteil, Diskrepanz zwischen Selbst- und Fremdeinschätzung, Diskrepanz zwischen Selbsteinschätzung und Testleistung) teils unterschiedliche Facetten der Selbsteinschätzung abbilden. Zum anderen deuten die Befunde darauf hin, dass Unterschiede zwischen den Diskrepanzen zwischen Selbst- und Fremdeinschätzung in verschiedenen Symptombereichen maßgeblich auf unterschiedliche Grade der Beeinträchtigung zurückzuführen sind und nicht Ausdruck einer domänenspezifischen Ausprägung der Einsichtsfähigkeit bei AD-Patienten sind. Diese Studienergebnisse werden in der vorliegenden Arbeit im Zusammenhang mit Erklärungsansätzen für Anosognosie bei AD diskutiert.

Objective: To study awareness of cognitive dysfunction in patients with very mild Alzheimer’s disease (AD) and subjects with mild cognitive impairment (MCI). Methods: A complaint interview covering 13 cognitive domains was administered to 82 AD and 79 MCI patients and their caregivers. The patient groups were comparable according to age and education, and Mini Mental State Examination (MMSE) scores were ≥24 in all cases. The discrepancy between the patients’ and caregivers’ estimations of impairments was taken as a measure of anosognosia. Results: Self-reports of cognitive difficulties were comparable for AD and MCI patients. However, while in comparison to caregivers MCI patients reported significantly more cognitive impairment (p < 0.05), AD patients complained significantly less cognitive dysfunctions (p < 0.001). Conclusions: While most MCI patients tend to overestimate cognitive deficits when compared to their caregiver’s assessment, AD patients in early stages of disease underestimate cognitive dysfunctions. Anosognosia can thus be regarded as a characteristic symptom at a stage of very mild AD (MMSE ≥24) but not MCI. Accordingly, medical history even in mildly affected patients should always include information from both patient and caregiver. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Objective: To study awareness of cognitive dysfunction in patients with very mild Alzheimer’s disease (AD) and subjects with mild cognitive impairment (MCI). Methods: A complaint interview covering 13 cognitive domains was administered to 82 AD and 79 MCI patients and their caregivers. The patient groups were comparable according to age and education, and Mini Mental State Examination (MMSE) scores were ≥24 in all cases. The discrepancy between the patients’ and caregivers’ estimations of impairments was taken as a measure of anosognosia. Results: Self-reports of cognitive difficulties were comparable for AD and MCI patients. However, while in comparison to caregivers MCI patients reported significantly more cognitive impairment (p < 0.05), AD patients complained significantly less cognitive dysfunctions (p < 0.001). Conclusions: While most MCI patients tend to overestimate cognitive deficits when compared to their caregiver’s assessment, AD patients in early stages of disease underestimate cognitive dysfunctions. Anosognosia can thus be regarded as a characteristic symptom at a stage of very mild AD (MMSE ≥24) but not MCI. Accordingly, medical history even in mildly affected patients should always include information from both patient and caregiver. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.