Acute right opercular stroke-associated polyopic heautoscopy and hallucinations caused by disconnection to the inferior parietal lobule through the superior longitudinal fasciculus III: A single case study.

Illusory neuropsychiatric symptoms such as hallucinations or the feeling of a presence (FOP) can occur in diffuse brain lesion or dysfunction, in psychiatric diseases as well as in healthy individuals. Their occurrence due to focal brain lesions is rare, most probably due to underreporting, which limits progress in understanding their underlying mechanisms and anatomical determinants. In this single case study, an 86-year-old patient experienced, in the context of an acute right central opercular ischemic stroke, visual hallucinatory symptoms (including palinopsia), differently lateralized auditory hallucinations and FOP. This unusual clinical constellation could be precisely documented and illustrated while still present, allowing a realistic and immersive visual experience validated by the patient. The acute stroke appeared to be their most plausible cause (after exclusion of other etiologies). Furthermore, accurate analysis of tractographic data suggested that disruption in the posterior bundle of the superior longitudinal fasciculus connecting the stroke lesion to the inferior parietal lobule was the anatomical substrate explaining the FOP and, indirectly, also hallucinations through whiter matter involvement, in coherence with existing literature. We could finally elaborate on symptoms taxonomy and phenomenology (e.g., polyopic heautoscopy, hallucinatory FOP, etc), and on patient's remarkable distancing from them (with some therapeutic implications supported by plausibly engaged mechanisms). This case not only authentically enriched the description of such rare combination of heterogenous illusory symptoms through this novel visualization-based reporting approach, but disclosed an unrevealed anatomo-clinical link relating all of them to the acute stroke lesion through an association fiber, thereby contributing to the understanding of these intriguing symptoms and their determinants.

Awake together: Sociopsychological processes of engagement in conspiracist communities.

Research on conspiracy theories tends to frame conspiracy believers as isolated individuals falling prey to irrational beliefs caused by a variety of pathological traits and cognitive shortcomings. But evidence is accumulating that conspiracy theory believers are also linked together in social movements capable of effectively coordinated collective action. We propose that conspiracy theory beliefs evolve over time, as part of a process of increasing disengagement from mainstream groups, and concomitant engagement in a community of like-minded individuals, capable of coordinated collective action. This approach allows portraying extreme conspiracism as attractive not despite its apparent irrationality, but precisely because of it. As such, conspiracy theories could not only be conceived as "beliefs" but also as "social signals" advertising a subversive "counter-elite" posture.

Pseudoexpertise: A Conceptual and Theoretical Analysis.

Some people publicly pretend to be experts while not being ones. They are pseudoexperts, and their presence seems to be ubiquitous in the current cultural landscape. This manuscript explores the nature and mechanisms of pseudoexpertise. We first provide a conceptual analysis of pseudoexperts based on prototypical cases of pseudoexpertise and recent philosophical work on the concept of expertise. This allows us to propose a definition that captures real-world cases of pseudoexpertise, distinguishes it from related but different concepts such as pseudoscience, and highlights what is wrong with pseudoexpertise. Next, based on this conceptual analysis, we propose a framework for further research on pseudoexpertise, built on relevant empirical and theoretical approaches to cultural cognition. We provide exploratory answers to three questions: why is there pseudoexpertise at all; how can pseudoexperts be successful despite not being experts; and what becomes of pseudoexperts in the long run. Together, these conceptual and theoretical approaches to pseudoexpertise draw a preliminary framework from which to approach the very troubling problem posed by persons usurping the capacities and reputations of genuine experts.

The right thalamic ventral posterolateral nucleus seems to be determinant for macrosomatognosia: a case report.

BACKGROUND: Macrosomatognosiais the illusory sensation of a substantially enlarged body part. This disorder of the body schema, also called "Alice in wonderland syndrome" is still poorly understood and requires careful documentation and analysis of cases. The patient presented here is unique owing to his unusual macrosomatognosia phenomenology, but also given the unreported localization of his most significant lesion in the right thalamus that allowed consistent anatomo-clinical analysis. CASE PRESENTATION: This 45-years old man presented mainly with long-lasting and quasi-delusional macrosomatognosia associated to sensory deficits, both involving the left upper-body, in the context of a right thalamic ischemic lesion most presumably located in the ventral posterolateral nucleus. Fine-grained probabilistic and deterministic tractography revealed the most eloquent targets of the lesion projections to be the ipsilateral precuneus, superior parietal lobule,but also the right primary somatosensory cortex and, to a lesser extent, the right primary motor cortex. Under stationary neurorehabilitation, the patient slowly improved his symptoms and could be discharged back home and, later on, partially return to work. CONCLUSION: We discuss deficient neural processing and integration of sensory inputs within the right ventral posterolateral nucleus lesion as possible mechanisms underlying macrosomatognosia in light of observed anatomo-clinical correlations. On the other hand, difficulty to classify this unique constellation of Alice in wonderland syndrome calls for an alternative taxonomy of cognitive and psychic aspects of illusory body-size perceptions.

Brain structural evidence for a frontal pole specialization in glossolalia.

Glossolalia is defined as the ritual oral production of phoneme sequences without recognizable semantic content. The functional underpinnings of glossolalia, and notably whether it consists of a highly specific or ordinary behavior, remain largely unresolved. We addressed this question by measuring the structural brain remodeling associated with the extensive practice of glossolalia in thirty experts. This approach enabled us to circumvent the limitations of functional imaging to reveal the neural correlates of behaviors elicited in specific contexts and involving movements incompatible with most imaging methods. Whole-brain regression analyses of glossolalia expertise with indices of grey and white matter structure revealed positive associations between practice time and grey matter volume within the left frontal pole and the right middle frontal gyrus. These findings suggest that glossolalia involves a degree of neurocognitive specialization, though not at the level of language control and production networks, but within domain-general executive areas. They further call for including multi-tasking and interference suppression as key processes in models of unrecognizable speech production. Our results also concur with current demonstrations that measures of brain structural remodeling may help identifying whether cognitive skills depend on networks specialization or on a recycling of already existing processes.

Creationism and conspiracism share a common teleological bias.

Teleological thinking - the attribution of purpose and a final cause to natural events and entities - has long been identified as a cognitive hindrance to the acceptance of evolution, yet its association to beliefs other than creationism has not been investigated. Here, we show that conspiracism - the proneness to explain socio-historical events in terms of secret and malevolent conspiracies - is also associated to a teleological bias. Across three correlational studies (N > 2000), we found robust evidence of a teleological link between conspiracism and creationism, which was partly independent from religion, politics, age, education, agency detection, analytical thinking and perception of randomness. As a resilient 'default' component of early cognition, teleological thinking is thus associated with creationist as well as conspiracist beliefs, which both entail the distant and hidden involvement of a purposeful and final cause to explain complex worldly events.

Birth and death of a phantom.

Patients with supernumerary phantom limb report experiencing an additional limb duplicating its physical counterpart, usually following a stroke with sensorimotor 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. Electromyographic 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.

Ganser Syndrome.

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, premorbid 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 dissociation 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 Syndrome.

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.

The bodily self: Insights from clinical and experimental research.

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.

Micromégas: Altered Body-Environment Scaling in Literary Fiction.

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.

Nothing Happens by Accident, or Does It? A Low Prior for Randomness Does Not Explain Belief in Conspiracy Theories.

Belief in conspiracy theories has often been associated with a biased perception of randomness, akin to a nothing-happens-by-accident heuristic. Indeed, a low prior for randomness (i.e., believing that randomness is a priori unlikely) could plausibly explain the tendency to believe that a planned deception lies behind many events, as well as the tendency to perceive meaningful information in scattered and irrelevant details; both of these tendencies are traits diagnostic of conspiracist ideation. In three studies, we investigated this hypothesis and failed to find the predicted association between low prior for randomness and conspiracist ideation, even when randomness was explicitly opposed to malevolent human intervention. Conspiracy believers' and nonbelievers' perceptions of randomness were not only indistinguishable from each other but also accurate compared with the normative view arising from the algorithmic information framework. Thus, the motto "nothing happens by accident," taken at face value, does not explain belief in conspiracy theories.

Experience-based Auditory Predictions Modulate Brain Activity to Silence as do Real Sounds.

Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accounts of filling-in phenomenon. We investigated the neurophysiological effects of internal models by testing whether single-trial electrophysiological responses to omitted sounds in a rule-based sequence of tones with varying pitch could be decoded from the responses to real sounds and by analyzing the ERPs to the omissions with data-driven electrical neuroimaging methods. The decoding of the brain responses to different expected, but omitted, tones in both passive and active listening conditions was above chance based on the responses to the real sound in active listening conditions. Topographic ERP analyses and electrical source estimations revealed that, in the absence of any stimulation, experience-based internal models elicit an electrophysiological activity different from noise and that the temporal dynamics of this activity depend on attention. We further found that the expected change in pitch direction of omitted tones modulated the activity of left posterior temporal areas 140-200 msec after the onset of omissions. Collectively, our results indicate that, even in the absence of any stimulation, internal models modulate brain activity as do real sounds, indicating that auditory filling in can be accounted for by predictive activity.

Distinct contributions of Brodmann areas 1 and 2 to body ownership.

Although body ownership--i.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 person's finger by asking participants to hold their palm against another person's 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 person's 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.

Sigmund Freud and hysteria: the etiology of psychoanalysis?

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 emphasizing 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.

High and low stimulus-driven conflict engage segregated brain networks, not quantitatively different resources.

Task-irrelevant information is constantly present in our environment and may interfere with the processing of the information necessary to achieve goal-directed behavior. While task goals determine which information must be suppressed, the demand for inhibitory control depends on the strength of the interference induced by incoming, task-irrelevant information. Whether the same or distinct inhibitory processes are engaged to suppress various degrees of interference from task-irrelevant information remains largely unresolved. We investigated this question by manipulating the strength of the conflict induced by automatic word reading in a classical color Stroop task. High conflict was induced by presenting words in participant's native language and low conflict by presenting words in a less familiar language. Behavioral performance and electrical neuroimaging analyses of event-related potentials to the words were analyzed following a two-by-two within-subject design with factors conflict strength (high; low) and color word/word ink congruency (congruent; incongruent). Behaviorally, we observed a significant conflict strength × congruency driven by a smaller Stroop effect in the low- than high conflict condition. Electrophysiologically, we observed a significant conflict strength × congruency interaction at the topographic level during the period of the N450 components, indicative of the engagement of distinct configurations of brain networks. No such interaction was found at the level of response strength. Electrical sources analyses localized the topographic effect within the anterior cingulate cortex and basal ganglia, left middle frontal and occipital areas. We interpret our results in terms of qualitatively distinct executive mechanisms for reactive inhibitory control in conditions of high versus low stimulus-driven conflict.

Doubles everywhere: literary contributions to the study of the bodily self.

The topic of the double is a hallmark of romantic, gothic, and fantastic literature. In the guise of the second self, the alter ego or the doppelgänger, fictional doubles have long fascinated critics, clinicians, and scientists. We review classical approaches to the theme and propose a broad clinical and neurocognitive framework from which to examine major instances of the motif in literature. Based on neurological disorders of the bodily self (including unilateral and whole body illusions and duplications), as well as related experimental approaches, we provide examples of literary depictions of bodily fragmentation and splitting; autoscopic hallucinations; the classical doppelgänger, second self, or heautoscopic double; the feeling of a presence; out-of-body experiences; and so-called near-death experiences. Examples include works from Guy de Maupassant, E.T.A. Hoffman, Edgar Allan Poe, Robert Louis Stevenson, Fyodor Dostoevsky, Rudyard Kipling, and others. We discuss these literary cases of doubles from a neurocognitive perspective, and suggest that common mechanisms of the bodily self are involved in the emergence of pathological illusory doubles, literary creations of the double, as well as widespread cultural and religious beliefs about the existence of doubles and the soul.

Stranger than fiction: literary and clinical amnesia.

This chapter broadly covers literary uses of amnesia and memory disorders. Amnesia in fiction offers authors an efficient and dramatic device to tackle themes such as identity, personal liberty, or guilt. We argue against the common complaint that fictional amnesia is scientifically inaccurate, pointing out that the goals of literature are different from those of science, that amnesia is still poorly understood, and that real-life cases can sometimes be stranger than fiction. The chapter provides examples from the neuropsychological literature, media reports, mythology, historical cases, detective stories, war stories, theatrical plays, and other genres. Special attention is given to retrograde and dissociative amnesia, as these are the most frequent types of amnesia portrayed in fiction, while other types of memory disorders are more shortly treated. We argue that the predominance of disorders affecting autobiographical memory in fiction is in itself a revealing fact about the mechanisms of human memory, illustrating how fictional treatments of pathology can inform back neurological and psychological research.

Balzac's Louis Lambert : schizophrenia before Kraepelin and Bleuler.

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.