Sebastian Dieguez

Conflicting and puzzling results in bodily illusions research might arise because researchers have been operating under the false premise that they were studying illusions. I suggest that the rubber-hand and full-body illusions are not illusions after all, but something else entirely, and believing otherwise is succumbing to the illusion illusion.

Ganser's syndrome is a rare and controversial condition, whose main and most striking feature is the production of approximate answers (or near misses) to very simple questions. For instance, asked how many legs a horse has, Ganser patients will reply " 5 " , and answers to plain arithmetic questions will likewise be wrong, but only slightly off the mark (e.g., 2 + 2 = 3). This symptom was originally described by Sigbert Ganser in 1897 in prisoners on remand and labeled Vorbeigehen (" to pass by "), although the term Vorbeireden (" to talk beside the point ") is also frequently used. A number of associated symptoms were also reported: " clouding of consciousness, " somatoform conversion disorder , hallucinations, sudden and spontaneous recovery, subsequent amnesia for the episode, pre-morbid traumatic psychosocial experience and/or (usually mild) head trauma. Etiological, epidemiological and diagnostic issues have never been resolved for Ganser's syndrome. Ganser saw it as a form of " twilight hysteria, " whereas others suggested that malingering, psychosis or dissocia-tion were more appropriate labels, oftentimes combined with organic impairment and a subjectively intolerable psychosocial context. A central conundrum of Ganser's syndrome is whether it could simultaneously be a cultural and pathological representation of insanity, whereas cognitive, organic, affective, motivational and social factors would converge towards a naïve idea of what mental illness should look like, especially through the provision of approximate answers.

Cotard's syndrome is often described as the delusional belief that one is dead or non-existent. However , Jules Cotard's initial description (1880) of the " delusion of negations " was much richer and also involved delusions and claims of immortality and enormity, feelings of damnation, and illusions of bodily dissolution and transformation. Alternatively conceived as an extreme case of depression, hypochondria, or psychosis, the condition is considered rare and remains poorly understood. Cotard himself provided a taxonomy and several explanations for the condition, focusing on its distinction from classical persecutory delusions and suggesting that it could be a kind of reversed grandiosity. He proposed a psychosensory basis in the dissolution of mental imagery, which he then extended to a more general psychomotor impairment of volition. Other early authors highlighted a disorder of the bodily self, and more recent theories postulated an impairment of right hemispheric functions, leading to perceptual and somatosensory feelings of unreality, which coupled with reasoning impairments and an internalized attributional style led in turn to beliefs of non-existence. However, despite its striking presentation and its relevance to our understanding of self-awareness, Cotard's syndrome remains an elusive condition, rarely reported and poorly researched.

Patients with supernumerary phantom limb report experiencing an additional limb duplicating its physical counterpart, usually following a stroke with senso-rimotor disturbances. Here, we report a short-lasting case of a right upper supernumerary phantom limb with unusual visuomotor features in a healthy participant during a pure Jacksonian motor seizure unexpectedly induced by continuous Theta-Burst Stimulation over the left primary motor cortex. Elec-tromyographic correlates of the event followed the phenomenological pattern of sudden appearance and brutal dissolution of the phantom, adding credit to the hypothesis that supernumerary phantom limb results from a dynamic resolution of conflictual multimodal information.

Le patriotisme et le nationalisme ont la cote. Avec du bon, et du moins bon. Évidemment, la flamme patriote a été ravivée par les attentats du 13 novembre. Mais ce sursaut a eu lieu sur un fond plus ancien de repli identitaire dont il nous faut démonter les rouages. Un cas d'école : Nadine Morano. Invitée politique de l'émission On n'est pas couché le samedi 26 sep-tembre, l'eurodéputée déclare alors : « Nous sommes un pays judéo-chrétien – le général de Gaulle le disait –, de race blanche, qui accueille des personnes étrangères. J'ai envie que la France reste la France. Je n'ai pas envie que la France devienne musulmane. » Ces propos, et principale-ment l'utilisation du terme « race », ont immédia-tement fait scandale et généré un lot de commen-taires considérable, la plupart franchement indignés. Pour sa défense, l'élue a indiqué que « c'est un mot qui est dans le dictionnaire, je ne vois pas en quoi il est choquant », tout en revendi-quant le droit au « débat » et à la « liberté d'expres-sion », en mettant en avant son « parler vrai », et en dénonçant la « bien-pensance qui consiste à nier ce que nous sommes ».

This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of their sensorimotor underpinnings in healthy participants. The first part of the article describes unilateral disorders of the bodily self, such as asomatognosia, feelings of amputation, supernumerary phantom limbs and somatoparaphrenia, as well as descriptions of non-lateralized disorders of the bodily self, including Alice in Wonderland syndrome and autoscopic hallucinations. Because the sensorimotor mechanisms of these disorders are unclear, we focus on clinical descriptions and insist on the importance of reporting clinical cases to better understand the full range of bodily disorders encountered in neurological diseases. The second part of the article presents the advantages of merging neuroscientific approaches of the bodily self with immersive virtual reality, robotics and neuroprosthetics to foster the understanding of the multisensory, motor and neural mechanisms of bodily representations.

Architectonic embodiment postulates a bidirectional link between bodily awareness and the architectural environment. The standard size and features of the human body, for instance, are thought to influence the structure of interiors and buildings, as well as their perception and appreciation. Whereas architectural practice and theory, the visual arts and more recently the cognitive sciences have explored this relationship of humans with their crafted environments, many fictional literary works have long experimented with alterations of body–environment scaling. This so-called Gulliver theme – popular in the science-fiction genre but also in children's literature and philosophical satire – reveals, as a recurrent thought-experiment, our preoccupation with proportions and our fascination for the infinitely small and large. Here I provide an overview of the altered scaling theme in literature, including classics such as Voltaire's Micromégas, Swift's Gulliver's Travels, Caroll's Alice, and Matheson's The Shrinking man, closely examining issues relevant to architectonic embodiment such as: bodily, perceptual, cognitive, affective, and social changes related to alterations in body size relative to people, objects and architectural environments. I next provide a taxonomy of the Gulliver theme and highlight its main psychological features, and then proceed to review relevant work from cognitive science. Although fictional alterations of body-environment scaling far outreach current possibilities in experimental research, I argue that the peripetiae and morals outlined in the literary realm, as products of the human imagination, provide a unique window into the folk-psychology of body and space.

Anecdotal reports of people having paranormal perceptions during near-death experiences are widespread, and it has been suggested that such claims could be tested scientifically. But is it ethical to research this topic on unresponsive and non consenting patients, as a new study purports to do?
A commentary published in Skeptical Inquirer, vol. 33(5), pp. 44-48, 2009, including rejoinders by Christopher C. French and Susan Blackmore.

Mirror behaviors in advanced dementia are: the mirror sign of Abely and Delmas, where the patient stares at his face (environment-driven behavior of Lhermitte); non recognition of the self in the mirror (autoprosopagnosia and/or delirious auto-Capgras); mirror agnosia of Ramachandran and Binkofski where the patient do not understand the concept of mirror and its use; the psychovisual reflex, or reflex pursuit of the eyes when passively moving a minrror in front of a patient (intact vision); mirror writing (procedural learning). We describe four demented patients with mirror behaviors assessing brain mechanisms of self recognition, social brain and mental and visuo-spatial manipulation of images and objects.

The psychopathology of stroke encompasses several psychiatric and behavioral disorders that have high prevalence in the geriatric population, reduce the patient autonomy and increase the caregiver's burden. These disorders are usually associated with other cognitive and neurological deficits, and are labelled as neuropsychiatric when the whole clinical picture is consistent with the specific dysfunction of a neural system or brain region. Thus the neuropsychiatry of stroke comprises disorders of the perception/identification of the self and the environment (anosognosia of hemiplegia, misidentification syndromes, confabulations, visual hallucinations, delirium and acute confusional state), amotivational syndromes (apathy and athymhormia), disorders of emotional reactivity (blunted affect, emotional incontinence, irritability, catastrophic reactions), poor impulse or ideation control (mania) and personality changes. The clinical profile of the subcortical vascular dementia also po...

The assessment of behavioural manifestations and mood disorders is not always considered an important part of the neurological examination. However, evidence is now overwhelming that these are more than frequent features of a large array of central nervous system disorders. This article reviews the behavioural and mood manifestations of four classical neurological diseases: epilepsy, stroke, Parkinson’s disease and multiple sclerosis.
Epilepsy has long been associated with peculiar affective and cognitive manifestations which can originate from neurobiological, iatrogen and psychosocial factors.The concept of epileptic personality described in patients with temporal seizures, which involves thought, emotional and sexual disorders, is well known. Mood disorders, psychotic features and aggressiveness (against others or oneself) have also been described. However, the mechanisms and the validity of this entity are still under debate.
Stroke, Parkinson’s disease and multiple sclerosis are conditions usually associated with disorders of the sensorimotor and cognitive systems. However, it is now increasingly being recognised that alterations in behaviour and mood are not uncommon in these syndromes. Indeed, these features may well play a critical role in the recovery pattern of those patients.
As much as 64% of stroke patients are liable to suffer from depression or anxiety. Other disorders, labelled as pseudo-depressive, include catastrophic reactions, emotional lability, pathological laughter and crying and psychotic-like complications. Patients with Parkinson’s disease can show a wide variety of neuropsychiatric disorders. Depression and anxiety are frequent and not necessarily correlated to the severity of parkinsonism. Other psychiatric features include obsessive-compulsive behaviours, apathy, alterations of emotional processing and psychotic fits often induced by the medication. These disorders are associated with cognitive impairments involving memory, speech and executive functions, which can ultimately lead to dementia in as much as 60% of cases.
Multiple sclerosis is associated with affective and cognitive disorders in about 50% of cases. Interestingly, these disorders are not correlated to the severity of purely neurological impairments, although they are correlated to the extent of everyday life handicap. The neuropsychiatric disorders include depression, anxiety and sometimes a state of euphoria involving episodes of pathological laughter and crying. Much rarer are cases of dementia, psychotic fits and bipolar disorders. The neurocognitive disorders are not necessarily linked to depression or other psychiatric ailments. Multiple sclerosis patients can show impairments in different domains such as memory, attention, speed of processing, executive functions and visuospatial abilities.

Although body ownershipi.e. the feeling that our bodies belong to us modulates activity within the primary somatosensory cortex (S1), it is still unknown whether this modulation occurs within a somatotopically defined portion of S1. We induced an illusory feeling of ownership for another persons finger by asking participants to hold their palm against another persons palm and to stroke the two joined index fingers with the index and thumb of their other hand. This illusion (numbness illusion) does not occur if the stroking is performed asynchronously or by the other person. We combined this somatosensory paradigm with ultra-high field functional magnetic resonance imaging finger mapping to study whether illusory body ownership modulates activity within different finger-specific areas of S1. The results revealed that the numbness illusion is associated with activity in Brodmann area (BA) 1 within the representation of the finger stroking the other persons finger and in BA 2 contralateral to the stroked finger. These results show that changes in bodily experience modulate the activity within certain subregions of S1, with a different finger topographical selectivity between the representations of the stroking and of the stroked hand, and reveal that the high degree of somatosensory specialization in S1 extends to bodily self-consciousness.

Les conduites spéculaires des démences avancées sont : le signe du miroir d’Abely et Delmas où le patient fixe son visage et s’arrange (comportement de dépendance à l’environnement de Lhermitte) ; la non-reconnaissance de soi dans le miroir (autoprosopagnosie et/ou délire des sosies de soi-même, auto- Capgras) ; l’agnosie du miroir de Ramachandran et Binkofski où le sujet ne comprend plus le concept de miroir et son fonctionnement; le réflexe psychovisuel : poursuite oculaire réflexe lors de la mobilisation passive d’un miroir en face du patient (vision préservée) ; l’écriture en miroir (apprentissage procédural). Nous décrivons quatre patients déments avec des conduites spéculaires interrogeant les réseaux cérébraux de la reconnaissance de soi, du cerveau social et de la manipulation mentale visuospatiale de l’image et de l’objet.

The acclaimed Italian directors Luchino Visconti and Federico Fellini had very different life trajectories that led them to become major figures in the history of cinema. Similarities, however, can be found in their debuts with the neorealist genre, their personalities, creative styles and politicocultural involvement, and ultimately in the neurological disease that struck them at the end of their careers. Both suffered a right-hemispheric stroke that left them hemiplegic on the left side. We review their life and career to put that event into perspective, and then discuss its aftermath for both artists in the light of our current knowledge of right-hemispheric functions. Visconti showed a tremendous resilience following the accident and managed to direct several films and plays as an infirm, whereas Fellini had to put an end to his career but still was able to display his talents to the neuropsychologists that treated him. A speculative account is given of the links between right-hemispheric symptomatology and the premorbid personality of these highly prolific patients.

Sigmund Freud developed a specific interest in hysteria after his stay with Professor Jean-Martin Charcot during the winter of 1885–1886, although his previous activity mainly consisted of neuropathology and general medical practice. Most of his initial studies on hysteria (hysteria in men, influence of subconscious ideas, role of traumas, and psychological and sexual factors) were indeed ‘borrowed’ from Charcot and his immediate followers, such as Pierre Janet and Paul Richer. Subsequently, Freud developed with Breuer a theory of hysteria which encompassed a mixture of Janet’s ‘fixed subconscious ideas’ with the ‘pathological secret’ concept of Moriz Benedikt. After their book Studies on Hysteria (1895), Freud interrupted his collaboration with Breuer and developed the concept of conversion of psychological problems into somatic manifestations, with a strong ‘sexualization’ of hysteria. Firstly, he believed that actual abuses had occurred in these patients (the ‘seduction’ theory), but then blamed them for having deceived him on that issue, so that he subsequently launched a ‘fantasy’ theory to explain the development of hysterical symptoms without the necessity of actual abuses. Like many of his contemporaries, and contrary to his claims, Freud did not follow a scientific process of verified experiments, but rather adapted his theories to the evolution of his own beliefs on psychological conditions, selectively emphasising the aspects of his ‘therapies’ with patients which supported his emerging ideas, with often abrupt changes in theoretical interpretations. While it remains difficult to get a clear, synthetic vision of what was Freud’s definite theory of hysteria, it is obvious that hysteria really was the origin of what would become Freud’s psychoanalytical theory. Indeed, psychoanalysis appears to have been initially developed by him largely in order to absorb and explain his many changes in the interpretation of hysterical manifestations.

Bilingualism beyond language : taking the double personality hypothesis seriously

Les bilingues ont-ils une « double personnalité » ? Au-delà des nombreuses anecdotes personnelles, rapportées par des bilingues, qui semblent venir à l’appui de cette thèse, des recherches relativement récentes lui ajoutent également un certain crédit scientifique. Après avoir rappelé certaines caractéristiques du cerveau bilingue, nous examinons les données suggérant que la première (L1) ou la seconde (L2) langue d’un bilingue déterminent, selon l’usage et le contexte, des perceptions de soi, des attitudes culturelles, des réactions émotionnelles, des stéréotypes sociaux, des prises de décision et des jugements moraux différents. Le bilinguisme dépasse donc largement le seul domaine du langage ou de la communication, intégrant des facteurs culturels et individuels – notamment affectifs –, et modulant l’individu et son comportement dans un vaste registre. L’étendue de cette variabilité intra-individuelle reste à déterminer, de même que ses implications sociales, neuroscientifiques et cliniques.

Do bilinguals have a “double personality” ? In addition to personal anecdotes from bilinguals themselves, recent scientific evidence brings some support to this hypothesis. We first survey some features of the bilingual brain, followed by findings suggesting that the first (L1) and second language (L2) of a bilingual individual determine, depending on the language’s use and context, different self-perceptions, cultural attitudes, emotional reactions, social stereotypes, decision making and moral judgments. Hence, bilingualism largely extends beyond the domains of language and communication, and integrates cultural and individual – especially affective – factors, modulating the individual and his/her behavior in a broad fashion. The magnitude of this intra-individual variability remains to be defined, as well as its social, neuroscientific and clinical implications.

Dieguez S. [Towards a social neuropsychology.] Schweiz Arch Neurol Psychiatr 2005;156:147–72.

The present article makes the case for a social neuropsychology. A number of data from various fields are reviewed that show the intrinsic social nature of our brain processes.Humans, the “social animal”, perceive their fellows and represent them in a very different way than they perceive and represent nonhuman objects and events. This simple insight, now backed up by solid behavioural and brain imaging results, is the heart of the so called social neurosciences.The simulation theory, the chameleon effect and emotional contagion are instances of this burgeoning approach in the behavioural sciences, all of which seem to be underlain by a principle of primitive empathy, which in turn appears to be implemented by a large-scale self-other resonance mechanism. The so-called mirror-system is often presented as a good neurobiological candidate for these phenomena, whereby a single neuronal network operates when a specific action or emotion is self-generated or when that action or emotion is simply perceived in others. In other words, perception and action are linked right down at the neurobiological level, and this overlap may explain our ease in perceiving others as individuals just “like us”. This occurs automatically, rapidly and mainly unconsciously, and may help to understand the many examples of motor, vocal, facial and behavioural mimicry in the human species that we review here. Such an all encompassing tendency, which has been largely overlooked in the scientific literature until recently, cannot be discarded as mere peculiarities and has to be included in cognitive and neuroscientific accounts of human behaviour. Primitive empathy must carefully have been selected during hominid evolution and we propose some of its adaptive functions – including group affiliation,altruism and the rapid spreading of cultural symbols and artefacts – as well as its drawbacks, like chauvinism and conformism. Seeing the human brain as a specialised device for mutual social understanding can shed new light on many of its disorders seen in clinical practice.We review some classic neurobehavioral syndromes, classifying them as empathic disorders, excesses of mimesis, lacks of mimesis and pathological emotional contagion. In light of all these insights, we then argue against what we see as a deep shortcoming in current neuropsychological practice, namely the failure to account for the social and contextual nature of cognitive processes, and make the case for a much needed research programme on those aspects. In the end, a thorough knowledge of how we perceive others and how the social environment modulates our minds may be the right approach to account for the much discussed human ability for self-awareness, as many thinkers already had the insight in the past.

Keywords: social neuroscience; empathy; mirror system; emotional contagion; mimicry; chameleon effect

Honoré de Balzac (1799–1850) is well known for his penetrating observations and descriptions of the burgeoning social life and emerging modernity of 19th century France. This chapter focuses on the novel Louis Lambert, first published in 1832. It is argued that its main character provides the first complete and convincing description of schizophrenia – 69 years before Kraepelin fully developed the concept of dementia praecox and 76 years before Bleuler coined the word ‘schizophrenia’. We consider the history of the concept of schizophrenia and the intriguing possibility that it is a recent disease. Indeed, if schizophrenia had always existed, it would seem odd that Balzac’s novel should be the very first convincing and complete literary account of the disease. This claim is examined by a thorough description of Louis Lambert’s symptoms as they appear in the text, and compared to other claims of priority (namely, Shakespeare’s King Lear and Gogol’s Diary of a Madman). The chapter also provides some background on Balzac’s relationship with mysticism, mental illness, and the world of psychiatry. We conclude with remarks regarding influences of Louis Lambert, the case for the priority of the novel as the princeps case of schizophrenia, and its relevance to the recency hypothesis of schizophrenia.

Ce texte a été initialement rédigé pour figurer dans mon livre Total Bullshit ! (Dieguez, 2018) et s'intitulait « Etude de cas I : La revanche d'un cancre ». Il n'a finalement pas été retenu pour diverses raisons, mais, quoi qu'il en soit, il s'agissait d'appliquer le concept théorique de bullshit, longuement développé dans les 4 premiers chapitres du livre, à un cas particulier afin d'en illustrer l'intérêt heuristique. De fait, on comprend à mon avis beaucoup mieux des anomalies telles que le cas Aberkane une fois qu'on a saisi ce qu'est et comment fonctionne le bullshit. Néanmoins, pour que le texte soit lisible sans que l'on se soit préalablement plongé dans les parties théoriques du livre, j'ai considérablement altéré le chapitre initial afin qu'il soit accessible isolément. Il va sans dire, cependant, que pour profiter d'une expérience de lecture optimale, l'utilisateur serait fort bien avisé de faire l'acquisition du livre, et d'y insérer mentalement le présent texte entre le chapitre 4 et le chapitre 5.
Le texte est également disponible à cette adresse : http://menace-theoriste.fr/bullshittez-votre-cerveau-et-liberez-votre-bullshit-la-methode-aberkane-et-leffet-gourou-inverse/#_ftn5, je remercie l'équipe de La Tronche en Biais (http://menace-theoriste.fr/la-tronche-en-biais/) d'avoir bien voulu l'héberger.