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1.
Comput Psychiatr ; 8(1): 92-118, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38948255

RESUMO

Patients with anorexia nervosa (AN) typically hold altered beliefs about their body that they struggle to update, including global, prospective beliefs about their ability to know and regulate their body and particularly their interoceptive states. While clinical questionnaire studies have provided ample evidence on the role of such beliefs in the onset, maintenance, and treatment of AN, psychophysical studies have typically focused on perceptual and 'local' beliefs. Across two experiments, we examined how women at the acute AN (N = 86) and post-acute AN state (N = 87), compared to matched healthy controls (N = 180) formed and updated their self-efficacy beliefs retrospectively (Experiment 1) and prospectively (Experiment 2) about their heartbeat counting abilities in an adapted heartbeat counting task. As preregistered, while AN patients did not differ from controls in interoceptive accuracy per se, they hold and maintain 'pessimistic' interoceptive, metacognitive self-efficacy beliefs after performance. Modelling using a simplified computational Bayesian learning framework showed that neither local evidence from performance, nor retrospective beliefs following that performance (that themselves were suboptimally updated) seem to be sufficient to counter and update pessimistic, self-efficacy beliefs in AN. AN patients showed lower learning rates than controls, revealing a tendency to base their posterior beliefs more on prior beliefs rather than prediction errors in both retrospective and prospective belief updating. Further explorations showed that while these differences in both explicit beliefs, and the latent mechanisms of belief updating, were not explained by general cognitive flexibility differences, they were explained by negative mood comorbidity, even after the acute stage of illness.

2.
J Neuropsychol ; 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38899773

RESUMO

The neuropsychological disorder of anosognosia for hemiplegia (AHP) can offer unique insights into the neurocognitive processes of body consciousness and representation. Previous studies have found associations between selective social cognition deficits and anosognosia. In this study, we examined how such social cognition deficits may directly interact with representations of one's body as disabled in AHP. We used a modified set of previously validated Theory of Mind (ToM) stories to create disability-related content that was related to post-stroke paralysis and to investigate differences between right hemisphere damage patients with (n = 19) and without (n = 19) AHP. We expected AHP patients to perform worse than controls when trying to infer paralysis-related mental states in the paralysis-related ToM stories and explored whether such differences depended on the inference patients were asked to perform (e.g. self or other referent perspective-taking). Using an advanced structural neuroimaging technique, we expected selective social cognitive deficits to be associated with posterior parietal cortex lesions and deficits in self-referent perspective-taking in paralysis-related mentalising to be associated with frontoparietal disconnections. Group- and individual-level results revealed that AHP patients performed worse than HP controls when trying to infer paralysis-related mental states. Exploratory lesion analysis results revealed some of the hypothesised lesions, but also unexpected white matter disconnections in the posterior body and splenium of the corpus collosum associated with a self-referent perspective-taking in paralysis-related ToM stories. The study has implications for the multi-layered nature of body awareness, including abstract, social perspectives and beliefs about the body.

3.
PLoS One ; 19(6): e0304417, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38865322

RESUMO

Touch offers important non-verbal possibilities for socioaffective communication. Yet most digital communications lack capabilities regarding exchanging affective tactile messages (tactile emoticons). Additionally, previous studies on tactile emoticons have not capitalised on knowledge about the affective effects of certain mechanoreceptors in the human skin, e.g., the C-Tactile (CT) system. Here, we examined whether gentle manual stroking delivered in velocities known to optimally activate the CT system (defined as 'tactile emoticons'), during lab-simulated social media communications could convey increased feelings of social support and other prosocial intentions compared to (1) either stroking touch at CT sub-optimal velocities, or (2) standard visual emoticons. Participants (N = 36) felt more social intent with CT-optimal compared to sub-optimal velocities, or visual emoticons. In a second, preregistered study (N = 52), we investigated whether combining visual emoticons with tactile emoticons, this time delivered at CT-optimal velocities by a soft robotic device, could enhance the perception of prosocial intentions and affect participants' physiological measures (e.g., skin conductance rate) in comparison to visual emoticons alone. Visuotactile emoticons conveyed more social intent overall and in anxious participants affected physiological measures more than visual emoticons. The results suggest that emotional social media communications can be meaningfully enhanced by tactile emoticons.


Assuntos
Emoções , Robótica , Mídias Sociais , Tato , Humanos , Masculino , Feminino , Emoções/fisiologia , Adulto , Tato/fisiologia , Adulto Jovem , Intenção , Percepção do Tato/fisiologia , Comunicação
4.
EClinicalMedicine ; 73: 102673, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38873633

RESUMO

Research has examined the relationship between interoception and anxiety, depression, and psychosis; however, it is unclear which aspects of interoception have been systematically examined, what the combined findings are, and which areas require further research. To answer these questions, we systematically searched and narratively synthesised relevant reviews, meta-analyses, and theory papers (total n = 34). Existing systematic reviews and meta-analyses (anxiety n = 2; depression n = 2; psychosis n = 0), focus on cardiac interoceptive accuracy (heartbeat perception), and indicate that heartbeat perception is not systematically impaired in anxiety or depression. Heartbeat perception might be poorer in people with psychosis, but further evidence is needed. Other aspects of interoception, such as different body systems and processing levels, have been studied but not systematically reviewed. We highlight studies examining these alternative bodily domains and levels, review the efficacy of interoception-based psychological interventions, and make suggestions for future research. Funding: Wellcome Trust UK.

5.
Aesthetic Plast Surg ; 48(13): 2561-2572, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38512407

RESUMO

Cosmetic surgery is ever more affordable and accessible, but carries physical and psychological risks. Yet, no study to date has directly examined risk-taking behaviour under controlled conditions, beyond self-report and in relation to cosmetic surgery attitudes. We used the Balloon Analogue Risk Task and advanced computational modelling to measure decision-making behaviour and identify the latent parameters driving behaviour associated with cosmetic surgery attitudes in women with no cosmetic surgery history (N = 265) and a subsample of women with a cosmetic surgery history (N = 24). Risk taking was higher in women with greater acceptance and history of cosmetic surgery. Computational modelling revealed increased risk taking in women with greater acceptance of cosmetic surgery when decisions were made with greater knowledge of loss (risk) and not when the likelihood of loss was unknown (uncertainty). When women with greater acceptance of cosmetic surgery made decisions, they also placed less emphasis on possible losses (reduced loss aversion). Our findings suggest that women seeking cosmetic procedures may be less sensitive to losses and thus make more risky decisions. Greater emphasis should be placed on communicating potential losses rather than just the associated risks to women considering cosmetic procedures.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Assunção de Riscos , Cirurgia Plástica , Humanos , Feminino , Adulto , Cirurgia Plástica/psicologia , Adulto Jovem , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Tomada de Decisões , Simulação por Computador , Medição de Risco , Pessoa de Meia-Idade
6.
Aust N Z J Psychiatry ; 58(4): 300-307, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38054446

RESUMO

Body dysmorphic disorder is a severe psychiatric condition characterised by a preoccupation with a perceived appearance flaw or flaws that are typically not observable to others. Although significant advances in understanding the disorder have been made in the past decade, current explanations focus on cognitive, behavioural and visual perceptual disturbances that contribute to the disorder. Such a focus does not consider how perception of the internal body or interoception may be involved, despite (1) clinical observations of disturbed perception of the body in body dysmorphic disorder and (2) disturbed interoception being increasingly recognised as a transdiagnostic factor underlying a wide range of psychopathologies. In this paper, we use an existing model of hierarchical brain function and neural (predictive) processing to propose that body dysmorphic disorder involves defective interoception, with perceived appearance flaws being the result of 'interoceptive prediction errors' that cause body parts to be experienced as 'not just right'. We aim to provide a framework for interoceptive research into body dysmorphic disorder, and outline areas for future research.


Assuntos
Transtornos Dismórficos Corporais , Interocepção , Humanos , Transtornos Dismórficos Corporais/diagnóstico
7.
Neuropsychologia ; 194: 108776, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38141962

RESUMO

Patients with a disturbed sense of limb ownership (DSO) offer a unique window of insight into the multisensory processes contributing to the sense of body ownership. A limited amount of past research has examined the role of sensory deficits in DSO, and even less is known regarding the role of patient self-reported somatosensory sensations in the pathogenesis of DSO. To address this lack of knowledge we first conducted a systematic scoping review following PRISMA-SR guidelines, examining current research into somatosensory deficits and patient self-reported somatosensory sensations in patients with DSO. Eighty studies, including 277 DSO patients, were identified. The assessment of sensory deficits was generally limited in scope and quality, and deficits in tactile sensitivity and proprioception were most frequently found. The reporting of somatosensory sensations was even less frequent, with instances of paraesthesia (pins-and-needles), stiffness/rigidity, numbness and warmth, coldness and heaviness amongst the deficits recorded. In a second part of the study, we sought to directly address the lack of evidence concerning the impact of patient self-reported somatosensory sensations in DSO by measuring DSO and self-reported somatosensory sensations in a large (n = 121) sample of right-hemisphere stroke patients including N = 65 with DSO and N = 56 hemiplegic controls. Results show that feelings of coldness and stiffness modulate DSO symptoms. Sense of heaviness and numbness are more frequent in patients with DSO but do not have a clear impact on disownership symptomology. Although preliminary, these results suggest a role of subjective sensations about the felt body in the sense of limb ownership.


Assuntos
Imagem Corporal , Propriedade , Humanos , Autorrelato , Hipestesia/etiologia , Propriocepção
8.
J Exp Psychol Gen ; 152(12): 3418-3432, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37768577

RESUMO

The understanding of eating disorders is hindered by the lack of integration between existing psychosocial and neurobiological approaches. We address this problem by developing a novel transdiagnostic and computational approach to eating restriction decisions. We first validated a novel paradigm which extends an established monetary risk task to involve body stimuli with psychosocial values. We used advanced behavioral data analysis of a large (total N = 539) sample of women from across the eating restraint spectrum, including those with anorexia nervosa (AN; n = 31), recovered from AN (n = 23), and subclinical women with varying levels of eating restraint (n = 485), obtained from an online experiment, public event, and laboratory-based study. We found that social and motivational values regarding body appearance have a significant effect on value-based, decision making in eating restriction. Subsequently, validated descriptive and predictive advanced computational modeling indicated that these behaviors are driven by an aversion to risk rather than loss, with desirable body outcomes being associated with less risk aversion, and undesirable body outcomes linked to greater risk aversion. These findings indicate that cognitive and social factors influence eating decisions by distinct mechanisms. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Anorexia Nervosa , Transtornos da Alimentação e da Ingestão de Alimentos , Humanos , Feminino , Anorexia Nervosa/psicologia , Afeto
9.
Psychiatry Clin Neurosci ; 77(10): 530-540, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37421414

RESUMO

Disturbed interoception (i.e., the sensing, awareness, and regulation of internal body signals) has been found across several mental disorders, leading to the development of interoception-based interventions (IBIs). Searching PubMed and PsycINFO, we conducted the first systematic review of randomized-controlled trials (RCTs) investigating the efficacy of behavioral IBIs at improving interoception and target symptoms of mental disorders in comparison to a non-interoception-based control condition [CRD42021297993]. Thirty-one RCTs fulfilled inclusion criteria. Across all studies, a pattern emerged with 20 (64.5%) RCTs demonstrating IBIs to be more efficacious at improving interoception compared to control conditions. The most promising results were found for post-traumatic stress disorder, irritable bowel syndrome, fibromyalgia and substance use disorders. Regarding symptom improvement, the evidence was inconclusive. The IBIs were heterogenous in their approach to improving interoception. The quality of RCTs was moderate to good. In conclusion, IBIs are potentially efficacious at improving interoception for some mental disorders. In terms of symptom reduction, the evidence is less promising. Future research on the efficacy of IBIs is needed.


Assuntos
Interocepção , Transtornos de Estresse Pós-Traumáticos , Transtornos Relacionados ao Uso de Substâncias , Humanos , Saúde Mental , Intervenção Psicossocial , Transtornos de Estresse Pós-Traumáticos/psicologia , Ensaios Clínicos Controlados Aleatórios como Assunto
10.
Conscious Cogn ; 109: 103480, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36764163

RESUMO

BACKGROUND: Strange face illusions describe a range of visual apparitions that occur when an observer gazes at their image reflected in a mirror or at another person's face in a dimly lit room. The illusory effects range from mild alterations in colour, or contrast, to the perception of distorted facial features, or new strange faces.The current review critically evaluates studies investigating strange face illusions, their methodological quality, and existing interpretations. METHOD: Searches conducted using Scopus, PubMed, ScienceDirect and the grey literature until June 2022 identified 21 studies (N = 1,132; healthy participants n = 1,042; clinical participants n = 90) meeting the inclusion criteria (i.e., providing new empirical evidence relating to strange face illusions). The total sample had a mean age of 28.3 years (SD = 10.31) and two thirds (67 %) of participants tested to date are female. Results are reported using the Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) guidelines. The review was preregistered at the Open Science Framework (OSF: https://osf.io/ek48d). RESULTS: Pooling data across studies, illusory new strange faces are experienced by 58% (95%CI 48 to 68) of nonclinical participants. Study quality as assessed by the Appraisal Tool for Cross-Sectional Studies (AXIS) revealed that 3/21 (14.28%) studies were rated as high, 9/21 (42.86%) as moderate and 9/21 (42.86%) as low quality. Whilst the items relating specifically to reporting quality scored quite highly, those relating to study design and possible biases were lower and more variable. Overall, study quality accounted for 87% of the variance in reporting rates for strange faces, with higher quality being associated with lower illusion rates. The prevalence of illusions was also significantly greater in samples that were older, had higher proportions of female participants and for the interpersonal dyad (IGDT) compared to the mirror gaze paradigm (MGT). The moderating impact of study quality persisted in a multiple meta-regression involving participant age, paradigm type (IGDT vs MGT) and level of feature distortion. Our review point to the importance of reduced light levels, face stimuli and prolonged eye fixation for strange face illusions to emerge. CONCLUSION: Strange face illusions reliably occur in both mirror-gazing and interpersonal gazing dyad paradigms. Further research of higher quality is required to establish the prevalence and particularly, the mechanisms underpinning strange face illusions.


Assuntos
Ilusões , Humanos , Feminino , Adulto , Masculino , Estudos Transversais , Face , Fixação Ocular , Transtornos Dissociativos
11.
iScience ; 26(2): 105955, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36718368

RESUMO

Following positive social exchanges, the neural representation of interactive space around the body (peripersonal space; PPS) expands, whereas we also feel consciously more comfortable being closer to others (interpersonal distance; ID). However, it is unclear how relational traits, such as attachment styles, interact with the social malleability of our PPS and ID. A first, exploratory study (N=48) using a visuo-tactile, augmented reality task, found that PPS depended on the combined effects of social context and attachment anxiety. A follow-up preregistered study (N = 68), showed that those with high attachment anxiety demonstrated a sharper differentiation between peripersonal and extrapersonal space, even in a non-social context. A final, preregistered large-scale survey (N = 19,417) found that people scoring high in attachment anxiety prefer closer ID and differentiate their ID less based on feelings of social closeness. We conclude that attachment anxiety reduces the social malleability of both peripersonal and interpersonal space.

12.
Cereb Cortex ; 33(3): 512-522, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-35235644

RESUMO

Neuropsychological disturbances in the sense of limb ownership provide unique opportunities to study the neurocognitive basis of body ownership. Previous small sample studies that showed discrete cortical lesions cannot explain why multisensory, affective, and cognitive manipulations alter disownership symptoms. We tested the novel hypothesis that disturbances in the sense of limb ownership would be associated not only with discrete cortical lesions but also with disconnections of white-matter tracts supporting specific functional networks. We drew on an advanced lesion-analysis and Bayesian statistics approach in 49 right-hemisphere patients (23 with and 26 without limb disownership). Our results reveal that disturbances in the sense of ownership are associated with lesions in the supramarginal gyrus and disconnections of a fronto-insular-parietal network, involving the frontal-insular and frontal inferior longitudinal tracts, confirming previous disconnection hypotheses. Together with previous behavioral and neuroanatomical results, these findings lead us to propose that the sense of body ownership involves the convergence of bottom-up, multisensory integration, and top-down monitoring of sensory salience based on contextual demands.


Assuntos
Imagem Corporal , Propriedade , Humanos , Imagem Corporal/psicologia , Teorema de Bayes , Lobo Parietal/diagnóstico por imagem
13.
Neuropsychologia ; 170: 108227, 2022 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-35364093

RESUMO

In recent decades, the research traditions of (first-person) embodied cognition and of (third-person) social cognition have approached the study of self-awareness with relative independence. However, neurological disorders of self-awareness offer a unifying perspective to empirically investigate the contribution of embodiment and social cognition to self-awareness. This study focused on a neuropsychological disorder of bodily self-awareness following right-hemisphere damage, namely anosognosia for hemiplegia (AHP). A previous neuropsychological study has shown AHP patients, relative to neurological controls, to have a specific deficit in third-person perspective taking and allocentric stance (the other unrelated to the self) in higher order mentalizing tasks. However, no study has tested if verbal awareness of motor deficits is influenced by perspective-taking and centrism and identified the related anatomical correlates. Accordingly, two novel experiments were conducted with right-hemisphere stroke patients with (n = 17) and without AHP (n = 17) that targeted either their own (egocentric, experiment 1) or another stooge patients (allocentric, experiment 2) motor abilities from a first-or-third person perspective. In both experiments, neurological controls showed no significant difference in perspective-taking, suggesting that social cognition is not a necessary consequence of right-hemisphere damage. More specifically, experiment 1 found AHP patients more aware of their own motor paralysis (egocentric stance) when asked from a third compared to a first-person perspective, using both group level and individual level analysis. In experiment 2, AHP patients were less accurate than controls in making allocentric judgements about the stooge patient, but with only a trend towards significance and with no difference between perspectives. As predicted, deficits in egocentric and allocentric third-person perspective taking were associated with lesions in the middle frontal gyrus, superior temporal and supramarginal gyri, and white matter disconnections were more prominent with deficits in allocentricity. Behavioural and neuroimaging results demonstrate the intersecting relationship between bodily self-awareness and self-and-other-directed metacognition or mentalisation.


Assuntos
Agnosia , Metacognição , Acidente Vascular Cerebral , Agnosia/etiologia , Agnosia/psicologia , Conscientização , Cognição , Hemiplegia/psicologia , Humanos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/psicologia
14.
J Clin Exp Neuropsychol ; 43(1): 91-104, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33588707

RESUMO

Introduction: Anosognosia for hemiplegia (AHP) is a condition in which patients with paralysis are unaware of their motor deficits. Research into AHP is important for improving its treatment and providing insight into the neurocognitive mechanism of motor awareness. Unfortunately, most studies use assessments with widely recognized limitations.The study aims at developing a psychometrically validated assessment of AHP.Method: We developed a 40-item Motor Unawareness Assessment (MUNA) and administered it to 131 right-hemisphere stroke patients. Principal Component Analysis (PCA) was used to identify the underlying factor structure. Receiver Operating Characteristics (ROC) analysis was used to determine diagnostic cutoffs, and Area Under the Curve (AUC) analysis used to assess these cutoffs. Relationships with demographic, clinical and neuropsychological variables were explored.Results: Five factors were identified: explicit motor awareness, implicit motor awareness, impaired sense of ownership, agency and illusory movement, and emotional reactions. Established cutoffs had excellent sensitivity and specificity. Clinical, neuropsychological and demographic variables did not predict overall MUNA score but were related to specific subcomponents.Conclusion: The MUNA can differentiate various facets of AHP and provides a detailed profile of (un)awareness. The MUNA can therefore provide robust assessment for research purposes and assist clinicians when developing targeted rehabilitation.


Assuntos
Agnosia/diagnóstico , Agnosia/fisiopatologia , Conscientização/fisiologia , Hemiplegia/complicações , Testes Neuropsicológicos , Acidente Vascular Cerebral/complicações , Idoso , Agnosia/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Brain Commun ; 2(1): fcaa034, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32954292

RESUMO

Right-hemisphere stroke can impair the ability to recognize one's contralesional body parts as belonging to one's self. The study of this so-called 'disturbed sense of limb ownership' can provide unique insights into the neurocognitive mechanisms of body ownership. In this study, we address a hypothesis built upon experimental studies on body ownership in healthy volunteers. These studies have shown that affective (pleasant) touch, an interoceptive modality associated with unmyelinated, slow-conducting C-tactile afferents, has a unique role in the sense of body ownership. In this study, we systematically investigated whether affective touch stimulation could increase body ownership in patients with a disturbed sense of limb ownership following right-hemisphere stroke. An initial feasibility study in 16 adult patients with acute stroke enabled us to optimize and calibrate an affective touch protocol to be administered by the bedside. The main experiment, conducted with a different sample of 26 right hemisphere patients, assessed changes in limb ownership elicited following self- (patient) versus other- (experimenter) generated tactile stimulation, using a velocity known to optimally activate C-tactile fibres (i.e. 3 cm/s), and a second velocity that is suboptimal for C-tactile activation (i.e. 18 cm/s). We further examined the specificity and mechanism of observed changes in limb ownership in secondary analyses looking at (i) the influence of perceived intensity and pleasantness of touch, (ii) touch laterality and (iii) level of disturbed sense of limb ownership on ownership change and (iv) changes in unilateral neglect arising from touch. Findings indicated a significant increase in limb ownership following experimenter-administered, C-tactile-optimal touch. Voxel-based lesion-symptom mapping identified damage to the right insula and, more substantially, the right corpus callosum, associated with a failure to increase body ownership following experimenter-administered, affective touch. Our findings suggest that affective touch can increase the sense of body-part ownership following right-hemisphere stroke, potentially due to its unique role in the multisensory integration processes that underlie the sense of body ownership.

16.
Elife ; 92020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31975686

RESUMO

Specific, peripheral C-tactile afferents contribute to the perception of tactile pleasure, but the brain areas involved in their processing remain debated. We report the first human lesion study on the perception of C-tactile touch in right hemisphere stroke patients (N = 59), revealing that right posterior and anterior insula lesions reduce tactile, contralateral and ipsilateral pleasantness sensitivity, respectively. These findings corroborate previous imaging studies regarding the role of the posterior insula in the perception of affective touch. However, our findings about the crucial role of the anterior insula for ipsilateral affective touch perception open new avenues of enquiry regarding the cortical organization of this tactile system.


Assuntos
Vias Aferentes , Córtex Cerebral , Prazer/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Percepção do Tato/fisiologia , Adulto , Vias Aferentes/fisiologia , Vias Aferentes/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Córtex Cerebral/fisiologia , Córtex Cerebral/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Física , Tato/fisiologia
17.
Elife ; 82019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31383259

RESUMO

The syndrome of Anosognosia for Hemiplegia (AHP) can provide unique insights into the neurocognitive processes of motor awareness. Yet, prior studies have only explored predominately discreet lesions. Using advanced structural neuroimaging methods in 174 patients with a right-hemisphere stroke, we were able to identify three neural systems that contribute to AHP, when disconnected or directly damaged: the (i) premotor loop (ii) limbic system, and (iii) ventral attentional network. Our results suggest that human motor awareness is contingent on the joint contribution of these three systems.


Assuntos
Agnosia/fisiopatologia , Hemiplegia/fisiopatologia , Desempenho Psicomotor , Acidente Vascular Cerebral/complicações , Idoso , Idoso de 80 Anos ou mais , Mapeamento Encefálico , Neuroimagem Funcional , Humanos , Pessoa de Meia-Idade
18.
Psychophysiology ; 56(10): e13430, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31283023

RESUMO

The vestibular system has been shown to contribute to multisensory integration by balancing conflictual sensory information. It remains unclear whether such modulation of exteroceptive (e.g., vision), proprioceptive, and interoceptive (e.g., affective touch) sensory sources is influenced by epistemically different aspects of tactile stimulation (i.e., felt from within vs. seen, vicarious touch). In the current study, we aimed to (a) replicate previous findings regarding the effects of galvanic stimulation of the right vestibular network in multisensory integration, and (b) examine vestibular contributions to multisensory integration when touch is felt but not seen (and vice versa). During artificial vestibular stimulation (LGVS, i.e., right vestibular stimulation), RGVS (i.e., bilateral stimulation), and sham (i.e., placebo stimulation), healthy participants (N = 36, Experiment 1; N = 37, Experiment 2) looked at a rubber hand while either their own unseen hand or the rubber hand were touched by affective or neutral touch. We found that (a) LGVS led to enhancement of vision over proprioception during visual only conditions (replicating our previous findings), and (b) LGVS (versus sham) favored proprioception over vision when touch was felt (Experiment 1), with the opposite results when touch was vicariously perceived via vision (Experiment 2) and with no difference between affective and neutral touch. We showed how vestibular signals modulate the weight of each sensory modality according to the context in which they are perceived and that such modulation extends to different aspects of tactile stimulation: felt and seen touch are differentially balanced in multisensory integration according to their epistemic relevance.


Assuntos
Tato/fisiologia , Vestíbulo do Labirinto/fisiologia , Adolescente , Adulto , Feminino , Humanos , Ilusões/fisiologia , Masculino , Pessoa de Meia-Idade , Estimulação Física , Propriocepção/fisiologia , Adulto Jovem
19.
BMJ Open ; 9(3): e024913, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30878983

RESUMO

INTRODUCTION: Anorexia nervosa (AN) is an eating disorder characterised by restriction of energy intake, fears of gaining weight and related body image disturbances. The oxytocinergic system has been proposed as a pathophysiological candidate for AN. Oxytocin is a neuropeptide involved in bodily processes (eg, breast feeding) and in the onset of social behaviours (eg, bonding). Studies investigating the effect of intranasal oxytocin (IN-OT) in AN showed that it can improve attentional bias for high-calorie food and fat bodies stimuli, and related stress. However, less is known about the effect of IN-OT on bodily awareness and body image distortions, key features of the disorder linked to its development, prognosis and maintenance. Here, we aim to investigate the effect of IN-OT on the perception of affective, C-tactile-optimal touch, known to be impaired in AN and on multisensory integration processes underlying a body ownership illusion (ie, rubber hand illusion). For exploratory purposes, we will also investigate the effect of IN-OT on another interoceptive modality, namely cardiac awareness and its relationship with affective touch. DESIGN, METHODS AND ANALYSIS: Forty women with AN and forty matched healthy controls will be recruited and tested in two separate sessions; self-administering IN-OT (40 IU) or placebo, intranasally, in a pseudo-randomised manner. The data from this double-blind, placebo-controlled, cross-over study will be analysed using linear mixed models that allow the use of both fixed (treatment levels) and random (subjects) effects in the same analysis. To address our main hypotheses, separate analyses will be run for the affective touch task, where the primary outcome dependent variable will be the pleasantness of the touch, and for the rubber hand illusion, where we will investigate multisensory integration quantified as subjective embodiment towards the rubber hand. In the latter, we will manipulate the synchronicity of touch and the size of the hand. ETHICS AND DISSEMINATION: Ethics approval has been obtained by National Research Ethics Service NRES Committee London (Queen's Square Committee, ref number 14/LO/1593). The results will be disseminated through conference presentations and publication in peer-reviewed journals.


Assuntos
Anorexia Nervosa , Transtornos Dismórficos Corporais , Ocitocina/administração & dosagem , Sensação , Tato/efeitos dos fármacos , Administração Intranasal , Adolescente , Adulto , Anorexia Nervosa/tratamento farmacológico , Anorexia Nervosa/fisiopatologia , Anorexia Nervosa/psicologia , Transtornos Dismórficos Corporais/tratamento farmacológico , Transtornos Dismórficos Corporais/fisiopatologia , Transtornos Dismórficos Corporais/psicologia , Imagem Corporal , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Ocitócicos/administração & dosagem , Estimulação Física , Sensação/efeitos dos fármacos , Sensação/fisiologia
20.
Psychol Assess ; 31(7): 839-850, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30802119

RESUMO

The Eating Disorder Examination Questionnaire (EDE-Q) is a widely used assessment of eating disorder psychopathology; however, EDE-Q norms are yet to be provided within a nonclinical U.K. adult sample. Second, there is considerable disagreement regarding the psychometric properties of this measure. Several alternative factor structures have been previously proposed, but very few have subsequently validated their new structure in independent samples and many are often confined to specific subpopulations. Therefore, in the current study, we provide norms of the original four-factor EDE-Q structure, and subsequently assess the psychometric properties of the EDE-Q in females and males using a large nonclinical U.K. sample (total N = 2459). EDE-Q norms were consistently higher in females compared with males across all samples. Initial confirmatory factor analyses (CFA) did not support the original 4-factor structure for females or males (Phase 1). However, subsequent exploratory factor analyses (EFA) revealed a 3-factor structure as being the optimal fit for both females and males, using an 18-item and 16-item model, respectively (Phase 2). For females, the newly proposed 18-item structure was validated within an independent student sample and further validated in an additional nonstudent sample. The 16-item 3-factor male structure was also validated within an independent nonstudent sample, but was marginally below accepted fit indices within an independent student sample (Phase 3). Taken together, the above findings suggest that the EDE-Q factor structure may require further reassessment, with greater focus on the qualitative differences in interpretation of EDE-Q items between females and males. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Inquéritos e Questionários/normas , Adolescente , Adulto , Análise Fatorial , Feminino , Humanos , Masculino , Psicometria/estatística & dados numéricos , Reino Unido , Adulto Jovem
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