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1.
Behav Brain Sci ; 46: e49, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-37017067

RESUMO

How do we switch between "playing along" and treating robots as technical agents? We propose interaction breakdowns to help solve this "social artifact puzzle": Breaks cause changes from fluid interaction to explicit reasoning and interaction with the raw artifact. These changes are closely linked to understanding the technical architecture and could be used to design better human-robot interaction (HRI).


Assuntos
Robótica , Humanos
2.
Stress ; 25(1): 267-275, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35855548

RESUMO

Several studies suggest a link between acute changes in inflammatory parameters due to an endotoxin or (psychological) stressor and the brain's stress response. The extent to which basal circulating levels of inflammatory markers are associated with the brain's stress response has been hardly investigated so far. In the present study, baseline plasma levels of the cytokine interleukin (IL)-6 were obtained and linked to neural markers of psychosocial stress using a modified version of the Montreal Imaging Stress Task in a sample of N = 65 healthy subjects (N = 39 female). Of three a-priori defined regions of interest - the amygdala, anterior insula, and anterior cingulate cortex - baseline IL-6 was significantly and negatively associated with stress-related neural activation in the right amygdala and left anterior insula. Our results suggest that baseline cytokines might be related to differences in the neural stress response and that this relationship could be inverse to that previously reported for induced acute changes in inflammation markers.


Assuntos
Tonsila do Cerebelo , Interleucina-6 , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/metabolismo , Citocinas , Feminino , Giro do Cíngulo/diagnóstico por imagem , Humanos , Interleucina-6/sangue , Imageamento por Ressonância Magnética/métodos , Estresse Psicológico/sangue
3.
Behav Brain Sci ; 41: e10, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29353573

RESUMO

Humans are highly social animals who critically need to remember information from social episodes in order to successfully navigate future social interactions. We propose that such episodic memories about social encounters are processed during sleep, following the learning experience, with sleep abstracting and consolidating social gist knowledge (e.g., beliefs, first impressions, or stereotypes) about others that supports relationships and interpersonal communication.


Assuntos
Memória Episódica , Animais , Humanos , Relações Interpessoais , Aprendizagem , Rememoração Mental , Sono
4.
Hum Brain Mapp ; 38(8): 4034-4046, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28504364

RESUMO

Mindfulness has been shown to reduce stress, promote health, and well-being, as well as to increase compassionate behavior toward others. It reduces distress to one's own painful experiences, going along with altered neural responses, by enhancing self-regulatory processes and decreasing emotional reactivity. In order to investigate if mindfulness similarly reduces distress and neural activations associated with empathy for others' socially painful experiences, which might in the following more strongly motivate prosocial behavior, the present study compared trait, and state effects of long-term mindfulness meditation (LTM) practice. To do so we acquired behavioral data and neural activity measures using functional magnetic resonance imaging (fMRI) during an empathy for social pain task while manipulating the meditation state between two groups of LTM practitioners that were matched with a control group. The results show increased activations of the anterior insula (AI) and anterior cingulate cortex (ACC) as well as the medial prefrontal cortex and temporal pole when sharing others' social suffering, both in LTM practitioners and controls. However, in LTM practitioners, who practiced mindfulness meditation just prior to observing others' social pain, left AI activation was lower and the strength of AI activation following the mindfulness meditation was negatively associated with trait compassion in LTM practitioners. The findings suggest that current mindfulness meditation could provide an adaptive mechanism in coping with distress due to the empathic sharing of others' suffering, thereby possibly enabling compassionate behavior. Hum Brain Mapp 38:4034-4046, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Córtex Cerebral/fisiologia , Empatia/fisiologia , Meditação , Atenção Plena , Percepção da Dor/fisiologia , Percepção Social , Adulto , Mapeamento Encefálico , Córtex Cerebral/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prática Psicológica
5.
BMC Psychiatry ; 17(1): 206, 2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28577550

RESUMO

BACKGROUND: Autism Spectrum Disorder (ASD) is a severe, lifelong neurodevelopmental disorder with early onset that places a heavy burden on affected individuals and their families. Due to the need for highly specialized health, educational and vocational services, ASD is a cost-intensive disorder, and strain on health care systems increases with increasing age of the affected individual. METHODS: The ASD-Net will study Germany's largest cohort of patients with ASD over the lifespan. By combining methodological expertise from all levels of clinical research, the ASD-Net will follow a translational approach necessary to identify neurobiological pathways of different phenotypes and their appropriate identification and treatment. The work of the ASD-Net will be organized into three clusters concentrating on diagnostics, therapy and health economics. In the diagnostic cluster, data from a large, well-characterized sample (N = 2568) will be analyzed to improve the efficiency of diagnostic procedures. Pattern classification methods (machine learning) will be used to identify algorithms for screening purposes. In a second step, the developed algorithm will be tested in an independent sample. In the therapy cluster, we will unravel how an ASD-specific social skills training with concomitant oxytocin administration can modulate behavior through neurobiological pathways. For the first time, we will characterize long-term effects of a social skills training combined with oxytocin treatment on behavioral and neurobiological phenotypes. Also acute effects of oxytocin will be investigated to delineate general and specific effects of additional oxytocin treatment in order to develop biologically plausible models for symptoms and successful therapeutic interventions in ASD. Finally, in the health economics cluster, we will assess service utilization and ASD-related costs in order to identify potential needs and cost savings specifically tailored to Germany. The ASD-Net has been established as part of the German Research Network for Mental Disorders, funded by the BMBF (German Federal Ministry of Education and Research). DISCUSSION: The highly integrated structure of the ASD-Net guarantees sustained collaboration of clinicians and researchers to alleviate individual distress, harm, and social disability of patients with ASD and reduce costs to the German health care system. TRIAL REGISTRATION: Both clinical trials of the ASD-Net are registered in the German Clinical Trials Register: DRKS00008952 (registered on August 4, 2015) and DRKS00010053 (registered on April 8, 2016).


Assuntos
Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/terapia , Pesquisa Biomédica , Pessoas com Deficiência , Comportamento Cooperativo , Feminino , Alemanha , Humanos , Masculino , Pesquisa
6.
Neuroimage ; 124(Pt A): 977-988, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26439515

RESUMO

Perceiving human faces constitutes a fundamental ability of the human mind, integrating a wealth of information essential for social interactions in everyday life. Neuroimaging studies have unveiled a distributed neural network consisting of multiple brain regions in both hemispheres. Whereas the individual regions in the face perception network and the right-hemispheric dominance for face processing have been subject to intensive research, the functional integration among these regions and hemispheres has received considerably less attention. Using dynamic causal modeling (DCM) for fMRI, we analyzed the effective connectivity between the core regions in the face perception network of healthy humans to unveil the mechanisms underlying both intra- and interhemispheric integration. Our results suggest that the right-hemispheric lateralization of the network is due to an asymmetric face-specific interhemispheric recruitment at an early processing stage - that is, at the level of the occipital face area (OFA) but not the fusiform face area (FFA). As a structural correlate, we found that OFA gray matter volume was correlated with this asymmetric interhemispheric recruitment. Furthermore, exploratory analyses revealed that interhemispheric connection asymmetries were correlated with the strength of pupil constriction in response to faces, a measure with potential sensitivity to holistic (as opposed to feature-based) processing of faces. Overall, our findings thus provide a mechanistic description for lateralized processes in the core face perception network, point to a decisive role of interhemispheric integration at an early stage of face processing among bilateral OFA, and tentatively indicate a relation to individual variability in processing strategies for faces. These findings provide a promising avenue for systematic investigations of the potential role of interhemispheric integration in future studies.


Assuntos
Face , Reconhecimento Facial/fisiologia , Lateralidade Funcional/fisiologia , Recrutamento Neurofisiológico/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Substância Cinzenta/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , Rede Nervosa/fisiologia , Lobo Occipital/fisiologia , Estimulação Luminosa , Pupila/fisiologia , Adulto Jovem
7.
Hum Brain Mapp ; 37(2): 730-44, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26611397

RESUMO

Computational approaches have great potential for moving neuroscience toward mechanistic models of the functional integration among brain regions. Dynamic causal modeling (DCM) offers a promising framework for inferring the effective connectivity among brain regions and thus unraveling the neural mechanisms of both normal cognitive function and psychiatric disorders. While the benefit of such approaches depends heavily on their reliability, systematic analyses of the within-subject stability are rare. Here, we present a thorough investigation of the test-retest reliability of an fMRI paradigm for DCM analysis dedicated to unraveling intra- and interhemispheric integration among the core regions of the face perception network. First, we examined the reliability of face-specific BOLD activity in 25 healthy volunteers, who performed a face perception paradigm in two separate sessions. We found good to excellent reliability of BOLD activity within the DCM-relevant regions. Second, we assessed the stability of effective connectivity among these regions by analyzing the reliability of Bayesian model selection and model parameter estimation in DCM. Reliability was excellent for the negative free energy and good for model parameter estimation, when restricting the analysis to parameters with substantial effect sizes. Third, even when the experiment was shortened, reliability of BOLD activity and DCM results dropped only slightly as a function of the length of the experiment. This suggests that the face perception paradigm presented here provides reliable estimates for both conventional activation and effective connectivity measures. We conclude this paper with an outlook on potential clinical applications of the paradigm for studying psychiatric disorders. Hum Brain Mapp 37:730-744, 2016. © 2015 Wiley Periodicals, Inc.


Assuntos
Encéfalo/fisiologia , Reconhecimento Facial/fisiologia , Imageamento por Ressonância Magnética/métodos , Teorema de Bayes , Mapeamento Encefálico/métodos , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Masculino , Vias Neurais/fisiologia , Testes Neuropsicológicos , Oxigênio/sangue , Estimulação Luminosa , Reprodutibilidade dos Testes , Adulto Jovem
8.
Cereb Cortex ; 25(8): 2065-75, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24518753

RESUMO

The experience of embarrassment provides a highly salient cue for the human moral apparatus. Interestingly, people also experience embarrassment on behalf of others' inappropriate conditions. The perceiver's embarrassment often lacks an equivalent expression of embarrassment in the social counterpart. The present study examines this phenomenon and distinguishes neural circuits involved in embarrassment with and embarrassment for another person's mishaps. Using functional magnetic resonance imaging, we show that the embarrassment on behalf of others engages the temporal pole and the medial prefrontal cortex, central structures of the mentalizing network, together with the anterior insula and anterior cingulate cortex. In contrast, sharing others' embarrassment additionally stimulated the posterior superior temporal sulcus (STS), which exhibited increased functional integration with inferior parietal and insular cortex areas. These findings characterize common neural circuits involved in the embodied representation of embarrassment and further unravel the unique role of the posterior STS in sharing others' affective state.


Assuntos
Emoções/fisiologia , Percepção Social , Lobo Temporal/fisiologia , Teoria da Mente/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiologia , Testes Neuropsicológicos , Acoplamento Neurovascular , Psicofísica , Adulto Jovem
9.
BMC Psychiatry ; 16(1): 329, 2016 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-27655235

RESUMO

BACKGROUND: Autism spectrum disorders are neurodevelopmental conditions with severe impairments in social communication and interaction. Pioneering research suggests that oxytocin can improve motivation, cognition and attention to social cues in patients with autism spectrum disorder. The aim of this clinical trial is to characterize basic mechanisms of action of acute oxytocin treatment on neural levels and to relate these to changes in different levels of socio-affective and -cognitive functioning. METHODS: This clinical study is a randomized, double-blind, cross-over, placebo-controlled, multicenter functional magnetic resonance imaging study with two arms. A sample of 102 male autism spectrum disorder patients, diagnosed with Infantile Autistic Disorder (F84.0 according to ICD-10), Asperger Syndrome (F84.5 according to ICD-10), or Atypical Autism (F84.1 according to ICD-10) will be recruited and will receive oxytocin and placebo nasal spray on two different days. Autism spectrum disorder patients will be randomized to determine who receives oxytocin on the first and who on the second visit. Healthy control participants will be recruited and case-control matched to the autism spectrum disorder patients. The primary outcome will be neural network activity, measured with functional magnetic resonance imaging while participants perform socio-affective and -cognitive tasks. Behavioral markers such as theory of mind accuracy ratings and response times will be assessed as secondary outcomes in addition to physiological measures such as skin conductance. Trait measures for alexithymia, interpersonal reactivity, and social anxiety will also be evaluated. Additionally, we will analyze the effect of oxytocin receptor gene variants and how these potentially influence the primary and secondary outcome measures. Functional magnetic resonance imaging assessments will take place at two time points which will be scheduled at least two weeks apart to ensure a sufficient wash-out time after oxytocin treatment. The study has been approved by an ethical review board and the competent authority. DISCUSSION: Revealing the mechanisms of acute oxytocin administration, especially on the socio-affective and -cognitive domains at hand, will be a further step towards novel therapeutic interventions regarding autism. TRIAL REGISTRATION: German Clinical Trial Register DRKS00010053 . The trial was registered on the 8th of April 2016.

10.
Neuroimage ; 117: 56-66, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26004501

RESUMO

Dynamic causal modeling (DCM) is a Bayesian framework for inferring effective connectivity among brain regions from neuroimaging data. While the validity of DCM has been investigated in various previous studies, the reliability of DCM parameter estimates across sessions has been examined less systematically. Here, we report results of a software comparison with regard to test-retest reliability of DCM for fMRI, using a challenging scenario where complex models with many parameters were applied to relatively few data points. Specifically, we examined the reliability of different DCM implementations (in terms of the intra-class correlation coefficient, ICC) based on fMRI data from 35 human subjects performing a simple motor task in two separate sessions, one month apart. We constructed DCMs of motor regions with fair to excellent reliability of conventional activation measures. Using classical DCM (cDCM) in SPM5, we found that the test-retest reliability of DCM results was high, both concerning the model evidence (ICC=0.94) and the model parameter estimates (median ICC=0.47). However, when using a more recent DCM version (DCM10 in SPM8), test-retest reliability was reduced notably. Analyses indicated that, in our particular case, the prior distributions played a crucial role in this change in reliability across software versions. Specifically, when using cDCM priors for model inversion in DCM10, this not only restored reliability but yielded even better results than in cDCM. Analyzing each component of the objective function in DCM, we found a selective change in the reliability of posterior mean estimates. This suggests that tighter regularization afforded by cDCM priors reduces the possibility of local extrema in the objective function. We conclude this paper with an outlook to ongoing developments for overcoming the software-dependency of reliability observed in this study, including global optimization and empirical Bayesian procedures.


Assuntos
Teorema de Bayes , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Córtex Motor/fisiologia , Córtex Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Modelos Neurológicos , Atividade Motora , Vias Neurais/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
11.
Hum Brain Mapp ; 36(11): 4730-44, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26367817

RESUMO

Autism spectrum disorder (ASD) is characterized by substantial social deficits. The notion that dysfunctions in neural circuits involved in sharing another's affect explain these deficits is appealing, but has received only modest experimental support. Here we evaluated a complex paradigm on the vicarious social pain of embarrassment to probe social deficits in ASD as to whether it is more potent than paradigms currently in use. To do so we acquired pupillometry and fMRI in young adults with ASD and matched healthy controls. During a simple vicarious physical pain task no differences emerged between groups in behavior, pupillometry, and neural activation of the anterior insula (AIC) and anterior cingulate cortex (ACC). In contrast, processing complex vicarious social pain yielded reduced responses in ASD on all physiological measures of sharing another's affect. The reduced activity within the AIC was thereby explained by the severity of autistic symptoms in the social and affective domain. Additionally, behavioral responses lacked correspondence with the anterior cingulate and anterior insula cortex activity found in controls. Instead, behavioral responses in ASD were associated with hippocampal activity. The observed dissociation echoes the clinical observations that deficits in ASD are most pronounced in complex social situations and simple tasks may not probe the dysfunctions in neural pathways involved in sharing affect. Our results are highly relevant because individuals with ASD may have preserved abilities to share another's physical pain but still have problems with the vicarious representation of more complex emotions that matter in life.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiopatologia , Empatia/fisiologia , Percepção da Dor/fisiologia , Pupila/fisiologia , Vergonha , Percepção Social , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
12.
Hum Brain Mapp ; 35(4): 1190-200, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23404764

RESUMO

BACKGROUND: Genome-wide association studies have identified the rs1006737 single nucleotide polymorphism (SNP) in the CACNA1C gene as a susceptibility locus for schizophrenia and bipolar disorder. On the neural systems level this association is explained by altered functioning of the dorsolateral prefrontal cortex (DLPFC) and the hippocampal formation (HF), brain regions also affected by mental illness. In the present study we investigated the association of rs1006737 genotype with prefrontal activation and fronto-hippocampal connectivity. METHODS: We used functional magnetic resonance imaging to measure neural activation during an n-back working memory task in 94 healthy subjects. All subjects were genotyped for the SNP rs1006737. We tested associations of the rs1006737 genotype with changes in working-memory-related DLPFC activation and functional integration using a seed region functional connectivity approach. RESULTS: Rs1006737 genotype was associated with altered right-hemispheric DLPFC activation. The homozygous A (risk) group showed decreased activation compared to G-allele carriers. Further, the functional connectivity analysis revealed a positive association of fronto-hippocampal connectivity with rs1006737 A alleles. CONCLUSIONS: We did not replicate the previous findings of increased right DLPFC activation in CACNA1C rs1006737 A homozygotes. In fact, we found the opposite effect, thus questioning prefrontal inefficiency as rs1006737 genotype-related intermediate phenotype. On the other hand, our results indicate that alterations in the functional coupling between the prefrontal cortex and the medial temporal lobe could represent a neural system phenotype that is mediated by CACNA1C rs1006737 and other genetic susceptibility loci for schizophrenia and bipolar disorder.


Assuntos
Canais de Cálcio Tipo L/genética , Lobo Frontal/fisiologia , Hipocampo/fisiologia , Memória de Curto Prazo/fisiologia , Polimorfismo de Nucleotídeo Único , Córtex Pré-Frontal/fisiologia , Alelos , Transtorno Bipolar/genética , Mapeamento Encefálico , Feminino , Predisposição Genética para Doença , Testes Genéticos , Heterozigoto , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiologia , Testes Neuropsicológicos , Fenótipo , Esquizofrenia/genética , Análise e Desempenho de Tarefas , Adulto Jovem
13.
Hum Brain Mapp ; 34(2): 304-13, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22042765

RESUMO

Genome-wide association studies identified the single nucleotide polymorphism rs1344706 in ZNF804A as a common risk-variant for schizophrenia and bipolar disorder. Whereas the molecular function of ZNF804A is yet unclear, recent imaging genetics studies have started to characterize the neural systems architecture linking rs1344706 genotype to psychosis. Carring rs1344706 risk-alleles was associated with a decrease in functional connectivity within the dorsolateral prefrontal cortices (DLPFCs) as well as an increase in connectivity between the DLPFC and the hippocampal formation (HF) in the context of a working memory task. The present study aimed at replicating these findings in an independent sample of 94 healthy subjects. Subjects were genotyped for rs1344706 and performed a working memory task during functional magnetic resonance imaging. Results indicate no support for a decrease of functional coupling between the bilateral DLPFCs at higher ZNF804A risk status. However, the current data show the previously described alteration in functional coupling between the right DLPFC and the HFs, albeit with weaker effects. Decoupled by default, the functional connectivity between the right DLPFC and anterior HFs increased with the number of rs1344706 risk alleles. The present data support fronto-hippocampal dysconnectivity as intermediate phenotype linking rs1344706 genotype to psychosis. We discuss the issues in replicating the interhemispheric DLPFC coupling in light of the effect sizes rs1344706 genotype has on brain function, concluding that further independent replication studies are fundamentally needed to ascertain the role of rs1344706 in the functional integration of neural systems.


Assuntos
Fatores de Transcrição Kruppel-Like/genética , Vias Neurais/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Mapeamento Encefálico , DNA/genética , Interpretação Estatística de Dados , Feminino , Lateralidade Funcional/fisiologia , Genótipo , Hipocampo/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Memória de Curto Prazo/fisiologia , Desempenho Psicomotor/fisiologia , Risco , Esquizofrenia/genética , Razão de Masculinidade , Adulto Jovem
14.
Neurocase ; 19(4): 348-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22512289

RESUMO

'Crossed language dominance' is a rare form of language lateralization, characterized by a dissociation of anterior and posterior language regions. We present the case of a healthy subject whose language lateralization pattern, as assessed by functional magnetic resonance imaging, is reliably characterized as crossed language dominance based on a word generation task, but typical left-lateralized when a semantic decision task is applied. A single language task is therefore not sufficient to characterize language lateralization, at least not for subjects with rare forms of language dominance. In the pre-surgical diagnostic of language lateralization, several language tasks tapping into different aspects of language functions should be applied.


Assuntos
Córtex Cerebral/fisiologia , Lateralidade Funcional/fisiologia , Idioma , Adulto , Córtex Cerebral/irrigação sanguínea , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue
15.
Behav Brain Sci ; 36(4): 427-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23883756

RESUMO

Second-person neuroscience offers a framework for the study of social emotions, such as embarrassment and pride. However, we propose that an enduring mental representation of oneself in relation to others without a continuous direct social interaction is possible. We call this state "social immersion" and will explain its impact on the neuroscience of social emotions.


Assuntos
Cognição/fisiologia , Relações Interpessoais , Neurônios-Espelho/fisiologia , Percepção Social , Teoria da Mente/fisiologia , Humanos
16.
Behav Brain Sci ; 36(6): 631-3; discussion 634-59, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24304773

RESUMO

Rapid eye movement (REM) dreaming results in "emotionally intelligent encoding," according to the target article. Building on this, we argue that elaborative encoding alters emotional processing of upcoming events and thereby functions as prospective emotion regulation. After elaborative encoding, future events are appraised differently and result in a redirected emotional response. Disturbed elaborative encoding might be relevant for emotional dysregulation in psychopathology.


Assuntos
Córtex Cerebral/fisiologia , Sonhos/fisiologia , Sonhos/psicologia , Hipocampo/fisiologia , Memória Episódica , Sono REM/fisiologia , Humanos
17.
Eur Arch Psychiatry Clin Neurosci ; 262(5): 403-14, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22189657

RESUMO

The N-methyl-D-aspartate receptor (NMDAR) has been implicated in the pathophysiology of schizophrenia. Administered to healthy individuals, a subanesthetic dose of the noncompetitive NMDAR antagonist ketamine reproduces several psychopathological symptoms commonly observed in patients with schizophrenia. In a counterbalanced, placebo-controlled, double-blind, within-participants study, fifteen healthy subjects were administered a continuous subanesthetic S-ketamine infusion while cortical activation was measured using functional magnetic resonance imaging. While being scanned, subjects performed an overt word generation task. Ketamine-induced psychopathological symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Ketamine administration elicited effects on psychopathology, including difficulties in abstract thinking, lack of spontaneity and flow of conversation as well as formal thought disorder. On a behavioral level, verbal fluency performance was unaffected. The PANSS score for formal thought disorder positively correlated with activation measures encompassing the left superior temporal gyrus, the right middle and inferior frontal gyrus and the precuneus. Difficulty in abstract thinking was correlated with pronounced activations in prefrontal as well as in anterior cingulate regions, whereas hyperactivations in the left superior temporal gyrus were found in association with a lack of spontaneity and flow of conversation. In the absence of behavioral impairments during verbal fluency, NMDAR blocking evoked psychopathological symptoms and cortical activations in regions previously reported in schizophrenia patients. The results provide further support for the hypothesis of an NMDAR dysfunction in the pathophysiology of schizophrenia.


Assuntos
Transtornos Cognitivos , Antagonistas de Aminoácidos Excitatórios/efeitos adversos , Ketamina/efeitos adversos , Transtornos Mentais , Comportamento Verbal/efeitos dos fármacos , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Mapeamento Encefálico , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/patologia , Transtornos Cognitivos/psicologia , Método Duplo-Cego , Lateralidade Funcional/efeitos dos fármacos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Transtornos Mentais/induzido quimicamente , Transtornos Mentais/patologia , Transtornos Mentais/psicologia , Oxigênio/sangue , Estimulação Luminosa , Escalas de Graduação Psiquiátrica , Vocabulário
18.
Clin Psychol Rev ; 98: 102204, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36216722

RESUMO

Social interactions are dynamic, context-dependent, and reciprocal events that influence prospective strategies and require constant practice and adaptation. This complexity of social interactions creates several research challenges. We propose a new framework encouraging future research to investigate not only individual differences in capacities relevant for social functioning and their underlying mechanisms, but also the flexibility to adapt or update one's social abilities. We suggest three key capacities relevant for social functioning: (1) social perception, (2) sharing emotions or empathizing, and (3) mentalizing. We elaborate on how adaptations in these capacities may be investigated on behavioral and neural levels. Research on these flexible adaptations of one's social behavior is needed to specify how humans actually "learn to be social". Learning to adapt implies plasticity of the relevant brain networks involved in the underlying social processes, indicating that social abilities are malleable for different contexts. To quantify such measures, researchers need to find ways to investigate learning through dynamic changes in adaptable social paradigms and examine several factors influencing social functioning within the three aformentioned social key capacities. This framework furthers insight concerning individual differences, provides a holistic approach to social functioning, and may improve interventions for ameliorating social abilities in patients.


Assuntos
Saúde Mental , Ajustamento Social , Humanos , Estudos Prospectivos , Percepção Social , Comportamento Social
19.
Commun Biol ; 5(1): 1241, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376497

RESUMO

The feedback people receive on their behavior shapes the process of belief formation and self-efficacy in mastering a particular task. However, the neural and computational mechanisms of how the subjective value of self-efficacy beliefs, and the corresponding affect, influence the learning process remain unclear. We investigated these mechanisms during self-efficacy belief formation using fMRI, pupillometry, and computational modeling, and by analyzing individual differences in affective experience. Biases in the formation of self-efficacy beliefs were associated with affect, pupil dilation, and neural activity within the anterior insula, amygdala, ventral tegmental area/ substantia nigra, and mPFC. Specifically, neural and pupil responses mapped the valence of the prediction errors in correspondence with individuals' experienced affective states and learning biases during self-efficacy belief formation. Together with the functional connectivity dynamics of the anterior insula within this network, our results provide evidence for neural and computational mechanisms of how we arrive at affected beliefs.


Assuntos
Mapeamento Encefálico , Imageamento por Ressonância Magnética , Humanos , Mapeamento Encefálico/métodos , Aprendizagem/fisiologia , Emoções , Substância Negra
20.
Biol Psychiatry Glob Open Sci ; 2(2): 136-146, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36325162

RESUMO

Background: Autism spectrum disorder (ASD) is characterized by difficulties in social communication and interaction, which have been related to atypical neural processing of rewards, especially in the social domain. As intranasal oxytocin has been shown to modulate activation of the brain's reward circuit, oxytocin might ameliorate the processing of social rewards in ASD and thus improve social difficulties. Methods: In this randomized, double-blind, placebo-controlled, crossover functional magnetic resonance imaging study, we examined effects of a 24-IU dose of intranasal oxytocin on reward-related brain function in 37 men with ASD without intellectual impairment and 37 age- and IQ-matched control participants. Participants performed an incentive delay task that allows the investigation of neural activity associated with the anticipation and receipt of monetary and social rewards. Results: Nonsignificant tests suggested that oxytocin did not influence neural processes related to the anticipation of social or monetary rewards in either group. Complementary Bayesian analyses indicated moderate evidence for a null model, relative to an alternative model. Our results were inconclusive regarding possible oxytocin effects on amygdala responsiveness to social rewards during reward consumption. There were no significant differences in reward-related brain function between the two groups under placebo. Conclusions: Our results do not support the hypothesis that intranasal oxytocin generally enhances activation of reward-related neural circuits in men with and without ASD.

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