Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
Neuroimage Clin ; 27: 102324, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32702624

RESUMO

Self-relevant functional abnormalities and identity disorders constitute the core psychopathological components in borderline personality disorder (BPD). Evidence suggests that appraising the relevance of environmental information to the self may be altered in BPD. However, only a few studies have examined self-relevance (SR) in BPD, and the neural correlates of SR processing has not yet been investigated in this patient group. The current study sought to evaluate brain activation differences between female patients with BPD and healthy controls during SR processing. A task-based fMRI paradigm was applied to evaluate SR processing in 23 female patients with BPD and 23 matched healthy controls. Participants were presented with a set of short sentences and were instructed to rate the stimuli. The differences in fMRI signals between SR rating (task of interest) and valence rating (control task) were examined. During SR rating, participants showed elevated activations of the cortical midline structures (CMS), known to be involved in the processing of self-related stimuli. Furthermore, we observed an elevated activation of the supplementary motor area (SMA) and the regions belonging to the mirror neuron system (MNS). Using whole-brain, seed-based connectivity analysis on the task-based fMRI data, we studied connectivity of networks anchored to the main CMS regions. We found a discrepancy in the connectivity pattern between patients and controls regarding connectivity of the CMS regions with the basal ganglia-thalamus complex. These observations have two main implications: First, they confirm the involvement of the CMS in SR evaluations of our stimuli and add evidence about the involvement of an extended network including the MNS and the SMA in this task. Second, the functional connectivity profile observed in BPD provides evidence for an altered functional interplay between the CMS and the brain regions involved in salience detection and reward evaluation, including the basal ganglia and the thalamus.


Assuntos
Transtorno da Personalidade Borderline , Transtorno da Personalidade Borderline/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Tálamo
2.
Biol Psychol ; 154: 107887, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32389836

RESUMO

Auditory mismatch processing is accompanied by activation of a distributed brain network which can be detected by fMRI. However, the impact of different experimental designs such as event-related or block designs and different stimulus characteristics on the auditory mismatch response and the activity of this network remains controversial. In the present study, we applied five auditory mismatch paradigms with standard experimental designs and recorded fMRI in 31 healthy participants. Brain activity was analyzed using general linear models as well as classification approaches. The results stress a greater role of the type of the applied deviant stimulus compared to the experimental design. Moreover, the absolute number of the deviants as well as the length of the experimental run seems to play a greater role than the experimental design. The present study promotes optimization of experimental paradigms in the context of mismatch research. In particular, our findings contribute to designing auditory mismatch paradigms for application in clinical settings.


Assuntos
Percepção Auditiva/fisiologia , Potenciais Evocados Auditivos , Imageamento por Ressonância Magnética , Estimulação Acústica , Adulto , Mapeamento Encefálico , Feminino , Humanos , Masculino
3.
Neuroimage Clin ; 28: 102483, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33395974

RESUMO

BACKGROUND: Traumatic experiences are associated with neurofunctional dysregulations in key regions of the emotion regulation circuits. In particular, amygdala responsivity to negative stimuli is exaggerated while engagement of prefrontal regulatory control regions is attenuated. Successful application of emotion regulation (ER) strategies may counteract this disbalance, however, application of learned strategies in daily life is hampered in individuals afflicted by posttraumatic stress disorder (PTSD). We hypothesized that a single session of real-time fMRI (rtfMRI) guided upregulation of prefrontal regions during an emotion regulation task enhances self-control during exposure to negative stimuli and facilitates transfer of the learned ER skills to daily life. METHODS: In a cross-over design, individuals with a PTSD diagnosis after a single traumatic event (n = 20) according to DSM-IV-TR criteria and individuals without a formal psychiatric diagnosis (n = 21) underwent a cognitive reappraisal training. In randomized order, all participants completed two rtfMRI neurofeedback (NF) runs targeting the left lateral prefrontal cortex (lPFC) and two control runs without NF (NoNF) while using cognitive reappraisal to reduce their emotional response to negative scenes. During the NoNF runs, two %%-signs were displayed instead of the two-digit feedback (FB) to achieve a comparable visual stimulation. The project aimed at defining the clinical potential of the training according to three success markers: (1) NF induced changes in left lateral prefrontal cortex and bilateral amygdala activity during the regulation of aversive scenes compared to cognitive reappraisal alone (primary registered outcome), (2) associated changes on the symptomatic and behavioral level such as indicated by PTSD symptom severity and affect ratings, (3) clinical utility such as indicated by perceived efficacy, acceptance, and transfer to daily life measured four weeks after the training. RESULTS: In comparison to the reappraisal without feedback, a neurofeedback-specific decrease in the left lateral PFC (d = 0.54) alongside an attenuation of amygdala responses (d = 0.33) emerged. Reduced amygdala responses during NF were associated with symptom improvement (r = -0.42) and less negative affect (r = -0.63) at follow-up. The difference in symptom scores exceeds requirements for a minimal clinically important difference and corresponds to a medium effect size (d = 0.64). Importantly, 75% of individuals with PTSD used the strategies in daily life during a one-month follow-up period and perceived the training as efficient. CONCLUSION: Our findings suggest beneficial effects of the NF training indicated by reduced amygdala responses that were associated with improved symptom severity and affective state four weeks after the NF training as well as patient-centered perceived control during the training, helpfulness and application of strategies in daily life. However, reduced prefrontal involvement was unexpected. The study suggests good tolerability of the training protocol and potential for clinical use in the treatment of PTSD.


Assuntos
Neurorretroalimentação , Transtornos de Estresse Pós-Traumáticos , Tonsila do Cerebelo/diagnóstico por imagem , Mapeamento Encefálico , Cognição , Estudos Cross-Over , Emoções , Humanos , Imageamento por Ressonância Magnética , Transtornos de Estresse Pós-Traumáticos/diagnóstico por imagem , Transtornos de Estresse Pós-Traumáticos/terapia
4.
Behav Brain Res ; 281: 326-32, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25461265

RESUMO

Deficits in emotion regulation are a prominent feature of psychiatric conditions and a promising target for treatment. For instance, cognitive reappraisal is regarded as an effective strategy for emotion regulation. Neurophysiological models have established the lateral prefrontal cortex (LPFC) as a key structure in the regulation of emotion processing through modulations of emotion-eliciting structures such as the amygdala. Feedback of the LPFC activity by real-time functional magnetic resonance (fMRI) may thus enhance the efficacy of cognitive reappraisal. During cognitive reappraisal of aversive visual stimuli, LPFC activity was fed back to the experimental group, whereas control participants received no such information. As a result, during reappraisal, amygdala activity was lower in the experimental group than in the controls. Furthermore, an increase of inter-hemispheric functional connectivity emerged in the feedback group. The current study extends the neurofeedback literature by suggesting that fMRI feedback can modify brain activity during a given task.


Assuntos
Tonsila do Cerebelo/fisiologia , Cognição/fisiologia , Emoções/fisiologia , Imageamento por Ressonância Magnética , Neurorretroalimentação/fisiologia , Adulto , Mapeamento Encefálico/métodos , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Percepção Visual/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA