Temporo-parietal cortex encodes location of the self: joining fMRI with neuroscience robotics to study bodily self-consciousness

Neuroimaging of the self has focused on high-level mechanisms such as language, memory or imagery of the self and implicated widely distributed brain networks. Yet recent evidence suggests that low-level mechanisms such as multisensory and sensorimotor integration may play a fundamental role in self-related processing. In the present study we used visuotactile multisensory conflict, robotics, virtual reality, and fMRI to study such low-level mechanisms by experimentally inducing changes in self-location. Participants saw a video of a person's back (body) or an empty room (no-body) being stroked while a MR-compatible robotic device stroked their back. The latter tactile input was synchronous or asynchronous with respect to the seen stroking. Self-location was estimated behaviorally confirming previous data that self-location only differed between the two body conditions. fMRI results showed a bilateral activation of the temporo-parietal cortex with a significantly higher BOLD signal increase in the synchronous/body condition with respect to the other conditions. Sensorimotor cortex and extrastriate-body-area were also activated. We argue that temporo-parietal activity reflects the experience of the conscious 'I' as embodied and localized within bodily space, compatible with clinical data in neurological patients with out-of-body experiences.

Neuroscience robotics to investigate multisensory integration and bodily awareness.

Humans experience the self as localized within their body. This aspect of bodily self-consciousness can be experimentally manipulated by exposing individuals to conflicting multisensory input, or can be abnormal following focal brain injury. Recent technological developments helped to unravel some of the mechanisms underlying multisensory integration and self-location, but the neural underpinnings are still under investigation, and the manual application of stimuli resulted in large variability difficult to control. This paper presents the development and evaluation of an MR-compatible stroking device capable of presenting moving tactile stimuli to both legs and the back of participants lying on a scanner bed while acquiring functional neuroimaging data. The platform consists of four independent stroking devices with a travel of 16-20 cm and a maximum stroking velocity of 15 cm/s, actuated over non-magnetic ultrasonic motors. Complemented with virtual reality, this setup provides a unique research platform allowing to investigate multisensory integration and its effects on self-location under well-controlled experimental conditions. The MR-compatibility of the system was evaluated in both a 3 and a 7 Tesla scanner and showed negligible interference with brain imaging. In a preliminary study using a prototype device with only one tactile stimulator, fMRI data acquired on 12 healthy participants showed visuo-tactile synchrony-related and body-specific modulations of the brain activity in bilateral temporoparietal cortex.

Multisensory mechanisms in temporo-parietal cortex support self-location and first-person perspective.

Self-consciousness has mostly been approached by philosophical enquiry and not by empirical neuroscientific study, leading to an overabundance of diverging theories and an absence of data-driven theories. Using robotic technology, we achieved specific bodily conflicts and induced predictable changes in a fundamental aspect of self-consciousness by altering where healthy subjects experienced themselves to be (self-location). Functional magnetic resonance imaging revealed that temporo-parietal junction (TPJ) activity reflected experimental changes in self-location that also depended on the first-person perspective due to visuo-tactile and visuo-vestibular conflicts. Moreover, in a large lesion analysis study of neurological patients with a well-defined state of abnormal self-location, brain damage was also localized at TPJ, providing causal evidence that TPJ encodes self-location. Our findings reveal that multisensory integration at the TPJ reflects one of the most fundamental subjective feelings of humans: the feeling of being an entity localized at a position in space and perceiving the world from this position and perspective.

Personality trait risk factors for attempted suicide among young women with eating disorders.

OBJECTIVE: - Clinical observations and a review of the literature led us to hypothesize that certain personality and character traits could provide improved understanding, and thus improved prevention, of suicidal behaviour among young women with eating disorders. METHOD: - The clinical group consisted of 152 women aged between 18 and 24 years, with DSM-IV anorexia nervosa/restrictive type (AN-R = 66), anorexia nervosa/purging type (AN-P = 37), bulimia nervosa/non-purging type (BN-NP = 9), or bulimia nervosa/purging type (BN-P = 40). The control group consisted of 140 subjects. The assessment measures were the Minnesota Multiphasic Personality Inventory-second version (MMPI-2) scales and subscales, the Beck Depression Inventory (BDI) used to control for current depressive symptoms, plus a specific questionnaire concerning suicide attempts. RESULTS: - Suicide attempts were most frequent in subjects with purging behaviour (30.0% for BN-P and 29.7% for AN-P). Those attempting suicide among subjects with eating disorders were mostly students (67.8%). For women with AN-R the scales for 'Depression' and 'Antisocial practices' represented significant suicidal risk, for women with AN-P the scales for 'Hysteria', 'Psychopathic deviate', 'Shyness/Self-consciousness', 'Antisocial Practices', 'Obsessiveness' and 'Low self-esteem' were risk indicators and for women with BN-P the 'Psychasthenia', 'Anger' and 'Fears' scales were risk indicators. CONCLUSION: - This study provides interesting results concerning the personality traits of young women with both eating disorders and suicidal behaviour. Students and those with purging behaviour are most at risk. Young women should be given more attention with regard to the risk of suicide attempts if they: (a). have AN-R with a tendency to self-punishment and antisocial conduct, (b). have AN-P with multiple physical complaints, are not at ease in social situations and have antisocial behaviour, or (c). if they have BN-P and tend to be easily angered with obsessive behaviour and phobic worries. The MMPI-2 is an interesting assessment method for the study of traits indicating a risk of suicidal behaviour in young subjects, after controlling for current depressive pathology.

Dépersonnalisation. Données actuelles.

OBJECTIVE: Depersonalization is a fascinating clinical phenomenon referring to a self-consciousness disorder, characterized by emotional detachment from one's own feelings, thoughts, or actions. This article intends to summarize the current literature in this area. METHOD: Using the Medline data base, we reviewed literature addressing the clinical, etiology, nosology, physiopathology, and treatment of depersonalization. CONCLUSIONS: Derealization means that perception of the world and of external reality are altered. These 2 phenomena are often associated. They are not specific to any psychiatric entity and are reported in many different psychiatric syndromes. Many factors, including use of different substances, are involved in their onset. The physiopathology is still little known. However, some conceptual models suggest partial amygdala inhibition combined with activation of other amygdaloid structures. A serotoninergic functioning impairment is indicated in different pharmacologic studies. Different psychotropic drugs, especially serotoninergic antidepressants, have been proposed for pharmacotherapy; however, there are no conclusive randomized studies, and the contribution of psychotherapy in treating these patients is still questioned

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.

Cultural competency of health-care providers in a Swiss University Hospital: self-assessed cross-cultural skillfulness in a cross-sectional study.

BACKGROUND: As the diversity of the European population evolves, measuring providers' skillfulness in cross-cultural care and understanding what contextual factors may influence this is increasingly necessary. Given limited information about differences in cultural competency by provider role, we compared cross-cultural skillfulness between physicians and nurses working at a Swiss university hospital. METHODS: A survey on cross-cultural care was mailed in November 2010 to front-line providers in Lausanne, Switzerland. This questionnaire included some questions from the previously validated Cross-Cultural Care Survey. We compared physicians' and nurses' mean composite scores and proportion of "3-good/4-very good" responses, for nine perceived skillfulness items (4-point Likert-scale) using the validated tool. We used linear regression to examine how provider role (physician vs. nurse) was associated with composite skillfulness scores, adjusting for demographics (gender, non-French dominant language), workplace (time at institution, work-unit "sensitized" to cultural-care), reported cultural-competence training, and cross-cultural care problem-awareness. RESULTS: Of 885 questionnaires, 368 (41.2%) returned the survey: 124 (33.6%) physicians and 244 (66.4%) nurses, reflecting institutional distribution of providers. Physicians had better mean composite scores for perceived skillfulness than nurses (2.7 vs. 2.5, p < 0.005), and significantly higher proportion of "good/very good" responses for 4/9 items. After adjusting for explanatory variables, physicians remained more likely to have higher skillfulness (β = 0.13, p = 0.05). Among all, higher skillfulness was associated with perception/awareness of problems in the following areas: inadequate cross-cultural training (β = 0.14, p = 0.01) and lack of practical experience caring for diverse populations (β = 0.11, p = 0.04). In stratified analyses among physicians alone, having French as a dominant language (β = -0.34, p < 0.005) was negatively correlated with skillfulness. CONCLUSIONS: Overall, there is much room for cultural competency improvement among providers. These results support the need for cross-cultural skills training with an inter-professional focus on nurses, education that attunes provider awareness to the local issues in cross-cultural care, and increased diversity efforts in the work force, particularly among physicians.

Behavioral changes in brain-injured critical care adults with different levels of consciousness during nociceptive stimulation: an observational study.

PURPOSE: The primary objective of this study was to describe the frequency of behaviors observed during rest, a non-nociceptive procedure, and a nociceptive procedure in brain-injured intensive care unit (ICU) patients with different levels of consciousness (LOC). Second, it examined the inter-rater reliability and discriminant and concurrent validity of the behavioral checklist used. METHODS: The non-nociceptive procedure involved calling the patient and shaking his/her shoulder. The nociceptive procedure involved turning the patient. The frequency of behaviors was recorded using a behavioral checklist. RESULTS: Patients with absence of movement, or stereotyped flexion or extension responses to a nociceptive stimulus displayed more behaviors during turning (median 5.5, range 0-14) than patients with localized responses (median 4, range 0-10) or able to self-report their pain (median 4, range 0-10). Face flushing, clenched teeth, clenched fist, and tremor were more frequent in patients with absence of movement, or stereotyped responses to a nociceptive stimulus. The reliability of the checklist was supported by a high intra-class correlation coefficient (0.77-0.92), and the internal consistency was acceptable in all three groups (KR 20, 0.71-0.85). Discriminant validity was supported as significantly more behaviors were observed during nociceptive stimulation than at rest. Concurrent validity was confirmed as checklist scores were correlated to the patients' self-reports of pain (r s = 0.53; 95 % CI 0.21-0.75). CONCLUSION: Brain-injured patients reacted significantly more during a nociceptive stimulus and the number of observed behaviors was higher in patients with a stereotyped response.

Self-deception as affective coping. An empirical perspective on philosophical issues.

In the philosophical literature, self-deception is mainly approached through the analysis of paradoxes. Yet, it is agreed that self-deception is motivated by protection from distress. In this paper, we argue, with the help of findings from cognitive neuroscience and psychology, that self-deception is a type of affective coping. First, we criticize the main solutions to the paradoxes of self-deception. We then present a new approach to self-deception. Self-deception, we argue, involves three appraisals of the distressing evidence: (a) appraisal of the strength of evidence as uncertain, (b) low coping potential and (c) negative anticipation along the lines of Damasio's somatic marker hypothesis. At the same time, desire impacts the treatment of flattering evidence via dopamine. Our main proposal is that self-deception involves emotional mechanisms provoking a preference for immediate reward despite possible long-term negative repercussions. In the last part, we use this emotional model to revisit the philosophical paradoxes.

Self, mémoire épisodique et narration chez l'enfant de 6 à 9 ans

Le self est une notion polysémique qui fait l'objet d'un consensus relatif dans plusieurs domaines, dont la psychologie du développement. Elle rend compte de la faculté de s'éprouver le même au fil du temps et de distinguer le « je » qui regarde du « moi » regardé. C'est le garant d'un sens de soi plus ou moins cohérent au fil du temps, en dépit des changements qui surviennent au cours de la vie. Le self combine des processus de réflexivité et d'intersubjectivité. Nous en avons analysé trois composantes fonctionnelles : la mémoire de travail, la mémoire épisodique et la narration, à partir d'un protocole expérimental témoignant de son ontogenèse chez des enfants de 6 à 9 ans (n=24 répartis en deux groupes de 6‐7 et 8-9 ans). Nous avons créé le « jeu informatique du lutin » qui propose un parcours semiorienté dans un monde imaginaire. C'est une narration de soi, opérant la mise en sens des temporalités et des espaces auxquels les événements se réfèrent. Deux semaines après cette « aventure », on recueille la narration des souvenirs épisodiques de cette histoire. Nous avons également utilisé un test de mémoire de travail visuospatiale non verbale. Des différences développementales affectent les dimensions narratives de la mémoire de l'épisode du jeu, comme l'efficacité de la mémoire de travail visuospatiale. Ces développements témoignent d'une augmentation de « l'épaisseur temporelle de la conscience» entre 6 et 9 ans. L'épaisseur de la conscience renvoie fondamentalement à la faculté du self de vivre le temps dans une cyclicité incluant le passé, le présent et le futur anticipé. Le développment observé élargit les possibilités de mettre en lien des mémoires et des scénarios futurs, tout comme les mises en sens des relations aux autres et à soi-­même. Self is a polysemic concept of common use in various scientific fields, among which developmental psychology. It accounts for the capacity to maintain the conviction to be « oneself », always the same through circumstances and throughout my life. This important function contributes in maintaining coherence and some sorte of Ariadne's thread in memory. To analyse the ontogeny of the self, we have focused upon three components : working memory, episodic memory and narration in children aged between 6 and 9 years. We used a non verbal working memory task. It was completed by a video game specially designed for our purpose, in which children were engaged in moving an elf in a landscape changing through seasons, in order to deliver a princess from a mischievous wizard. Two weeks after the game, the children had to tell what happened while they moved the elf. It is a self-narrative that creates a link‐up of temporality and spaces to which the events refer. The narrated episode was assessed for its coherence and continuity dimensions. Developmental differences affect the narrative dimensions of the memory of the episode of the game, as the effectiveness of visuospatial working memory. These developments show an increase in "temporal thickness of consciousness" between 6 and 9 years. The thickness of consciousness basically refers to the ability of the self to live in a cyclical time including past, present and anticipated future. The observed development broadens the possibilities to link memories and future scenarios, like setting sense of relations with others and with oneself.

Evaluation de la douleur chez les personnes cérébrolésées non-communicantes aux soins intensifs

La douleur est fréquente en milieu de soins intensifs et sa gestion est l'une des missions des infirmières. Son évaluation est une prémisse indispensable à son soulagement. Cependant lorsque le patient est incapable de signaler sa douleur, les infirmières doivent se baser sur des signes externes pour l'évaluer. Les guides de bonne pratique recommandent chez les personnes non communicantes l'usage d'un instrument validé pour la population donnée et basé sur l'observation des comportements. A l'heure actuelle, les instruments d'évaluation de la douleur disponibles ne sont que partiellement adaptés aux personnes cérébrolésées dans la mesure où ces personnes présentent des comportements qui leur sont spécifiques. C'est pourquoi, cette étude vise à identifier, décrire et valider des indicateurs, et des descripteurs, de la douleur chez les personnes cérébrolésées. Un devis d'étude mixte multiphase avec une dominante quantitative a été choisi pour cette étude. Une première phase consistait à identifier des indicateurs et des descripteurs de la douleur chez les personnes cérébrolésées non communicantes aux soins intensifs en combinant trois sources de données : une revue intégrative des écrits, une démarche consultative utilisant la technique du groupe nominal auprès de 18 cliniciens expérimentés (6 médecins et 12 infirmières) et les résultats d'une étude pilote observationnelle réalisée auprès de 10 traumatisés crâniens. Les résultats ont permis d'identifier 6 indicateurs et 47 descripteurs comportementaux, vocaux et physiologiques susceptibles d'être inclus dans un instrument d'évaluation de la douleur destiné aux personnes cérébrolésées non- communicantes aux soins intensifs. Une deuxième phase séquentielle vérifiait les propriétés psychométriques des indicateurs et des descripteurs préalablement identifiés. La validation de contenu a été testée auprès de 10 experts cliniques et 4 experts scientifiques à l'aide d'un questionnaire structuré qui cherchait à évaluer la pertinence et la clarté/compréhensibilité de chaque descripteur. Cette démarche a permis de sélectionner 33 des 47 descripteurs et valider 6 indicateurs. Dans un deuxième temps, les propriétés psychométriques de ces indicateurs et descripteurs ont été étudiés au repos, lors de stimulation non nociceptive et lors d'une stimulation nociceptive (la latéralisation du patient) auprès de 116 personnes cérébrolésées aux soins intensifs hospitalisées dans deux centres hospitaliers universitaires. Les résultats montrent d'importantes variations dans les descripteurs observés lors de stimulation nociceptive probablement dues à l'hétérogénéité des patients au niveau de leur état de conscience. Dix descripteurs ont été éliminés, car leur fréquence lors de la stimulation nociceptive était inférieure à 5% ou leur fiabilité insuffisante. Les descripteurs physiologiques ont tous été supprimés en raison de leur faible variabilité et d'une fiabilité inter juge problématique. Les résultats montrent que la validité concomitante, c'est-à-dire la corrélation entre l'auto- évaluation du patient et les mesures réalisées avec les descripteurs, est satisfaisante lors de stimulation nociceptive {rs=0,527, p=0,003, n=30). Par contre la validité convergente, qui vérifiait l'association entre l'évaluation de la douleur par l'infirmière en charge du patient et les mesures réalisés avec les descripteurs, ainsi que la validité divergente, qui vérifiait si les indicateurs discriminent entre la stimulation nociceptive et le repos, mettent en évidence des résultats variables en fonction de l'état de conscience des patients. Ces résultats soulignent la nécessité d'étudier les descripteurs de la douleur chez des patients cérébrolésés en fonction du niveau de conscience et de considérer l'hétérogénéité de cette population dans la conception d'un instrument d'évaluation de la douleur pour les personnes cérébrolésées non communicantes aux soins intensifs. - Pain is frequent in the intensive care unit (ICU) and its management is a major issue for nurses. The assessment of pain is a prerequisite for appropriate pain management. However, pain assessment is difficult when patients are unable to communicate about their experience and nurses have to base their evaluation on external signs. Clinical practice guidelines highlight the need to use behavioral scales that have been validated for nonverbal patients. Current behavioral pain tools for ICU patients unable to communicate may not be appropriate for nonverbal brain-injured ICU patients, as they demonstrate specific responses to pain. This study aimed to identify, describe and validate pain indicators and descriptors in brain-injured ICU patients. A mixed multiphase method design with a quantitative dominant was chosen for this study. The first phase aimed to identify indicators and descriptors of pain for nonverbal brain- injured ICU patients using data from three sources: an integrative literature review, a consultation using the nominal group technique with 18 experienced clinicians (12 nurses and 6 physicians) and the results of an observational pilot study with 10 traumatic brain injured patients. The results of this first phase identified 6 indicators and 47 behavioral, vocal and physiological descriptors of pain that could be included in a pain assessment tool for this population. The sequential phase two tested the psychometric properties of the list of previously identified indicators and descriptors. Content validity was tested with 10 clinical and 4 scientific experts for pertinence and comprehensibility using a structured questionnaire. This process resulted in 33 descriptors to be selected out of 47 previously identified, and six validated indicators. Then, the psychometric properties of the descriptors and indicators were tested at rest, during non nociceptive stimulation and nociceptive stimulation (turning) in a sample of 116 brain-injured ICLI patients who were hospitalized in two university centers. Results showed important variations in the descriptors observed during the nociceptive stimulation, probably due to the heterogeneity of patients' level of consciousness. Ten descriptors were excluded, as they were observed less than 5% of the time or their reliability was insufficient. All physiologic descriptors were deleted as they showed little variability and inter observer reliability was lacking. Concomitant validity, testing the association between patients' self report of pain and measures performed using the descriptors, was acceptable during nociceptive stimulation (rs=0,527, p=0,003, n=30). However, convergent validity ( testing for an association between the nurses' pain assessment and measures done with descriptors) and divergent validity (testing for the ability of the indicators to discriminate between rest and a nociceptive stimulation) varied according to the level of consciousness These results highlight the need to study pain descriptors in brain-injured patients with different level of consciousness and to take into account the heterogeneity of this population forthe conception of a pain assessment tool for nonverbal brain-injured ICU patients.