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1.
Schizophr Res ; 270: 220-228, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38924940

RESUMEN

BACKGROUND: Neurocognitive impairment is a core feature of schizophrenia spectrum disorders (SSDs), and the relationship between cognition and symptoms in SSDs has been widely researched. Negative symptoms are related to a wide range of cognitive impairments; however, the aspects of negative symptoms that underpin this relationship have yet to be specified. STUDY DESIGN: We used iterative Constrained Principal Component Analysis (iCPCA) to explore the relationship between 18 cognitive measures (including processing speed, attention, working, spatial and verbal memory and executive functions) and 46 symptoms in schizophrenia at the individual item level while minimizing the risk of Type I errors. ICPCA was conducted on a sample of SSD patients in the early stages of psychiatric treatment (n = 121) to determine the components of cognition overlapping with symptoms measured by the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS). RESULTS: We found that a verbal memory component was associated with items from SANS and SAPS related to impoverished and disorganized emotional communication, language, and thought. In contrast, a working memory component was associated with SANS items related to motor system impoverishment. CONCLUSIONS: The iCPCA allowed us to explore the associations between individual items, optimized to understand the overlap between symptoms and cognition. The specific symptoms linked to verbal and working memory impairments imply distinct brain networks, which further investigation may lead to our deeper understanding of the illness and the development of treatment methods.


Asunto(s)
Individualidad , Análisis de Componente Principal , Esquizofrenia , Psicología del Esquizofrénico , Humanos , Esquizofrenia/fisiopatología , Esquizofrenia/complicaciones , Masculino , Femenino , Adulto , Pruebas Neuropsicológicas , Adulto Joven , Escalas de Valoración Psiquiátrica , Persona de Mediana Edad , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/diagnóstico , Función Ejecutiva/fisiología
2.
Psychiatry Res Neuroimaging ; 341: 111824, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38754348

RESUMEN

Auditory verbal hallucinations (AVHs) involve perceptions, often voices, in the absence of external stimuli, and rank among the most common symptoms of schizophrenia. Metrical stress evaluation requires determination of the stronger syllable in words, and therefore requires auditory imagery, of interest for investigation of hallucinations in schizophrenia. The current functional magnetic resonance imaging study provides an updated whole-brain network analysis of a previously published study on metrical stress, which showed reduced directed connections between Broca's and Wernicke's regions of interest (ROIs) for hallucinations. Three functional brain networks were extracted, with the language network (LN) showing an earlier and shallower blood-oxygen-level dependent (BOLD) response for hallucinating patients, in the auditory imagery condition only (the reduced activation for hallucinations observed in the original ROI-based results were not specific to the imagery condition). This suggests that hypoactivation of the LN during internal auditory imagery may contribute to the propensity to hallucinate. This accords with cognitive accounts holding that an impaired balance between internal and external linguistic processes (underactivity in networks involved in internal auditory imagery and overactivity in networks involved in speech perception) contributes to our understanding of the biological underpinnings of hallucinations.


Asunto(s)
Alucinaciones , Imagen por Resonancia Magnética , Esquizofrenia , Humanos , Alucinaciones/fisiopatología , Alucinaciones/diagnóstico por imagen , Alucinaciones/psicología , Alucinaciones/etiología , Esquizofrenia/fisiopatología , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/complicaciones , Adulto , Masculino , Femenino , Imaginación/fisiología , Lenguaje , Mapeo Encefálico/métodos , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiopatología , Encéfalo/fisiopatología , Encéfalo/diagnóstico por imagen , Percepción Auditiva/fisiología
3.
Indian J Palliat Care ; 30(1): 77-80, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38633677

RESUMEN

Dyspnoea is a debilitating symptom in medicine, especially in palliative care. Opioids are the pharmacological agents of choice in the treatment of dyspnoea in palliative medicine. Morphine is the best-studied opioid, and recent literature on oxycodone is encouraging. In refractory cases, opioid infusion and palliative sedation may have to be used. We present a case that used oxycodone in a patient-controlled device specifically for dyspnoea and its effects in relieving dyspnoea in a fast and timely manner. This helped in meeting the demands of the patient and relieving suffering rapidly with less sedation. This case report is unique in the use of an oxycodone patient-controlled device specifically for dyspnoea.

4.
Indian J Palliat Care ; 30(1): 34-40, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38633688

RESUMEN

Objectives: Our research aimed to examine the characteristics of palliative oncology patients hospitalised through an emergency to look for the symptom profile, characteristics of dyselectrolytemia and blood investigations, and possible associations with mortality. Materials and Methods: After institutional review board approval, a retrospective, observational study of patients hospitalised in our tertiary care specialty oncology hospital was undertaken. Records of hospitalised cancer patients admitted from the emergency department under palliative care from January 2019 to October 2021 were examined. As all admissions during this period were through emergency due to institution COVID-19 protocols, all elective admissions were excluded from the study. Data collected included patient characteristics, blood investigations, and comorbid history of systemic diseases and factors that could be associated with electrolyte imbalance. Results: There were 157 emergency admissions during the study period. A majority were patients with solid tumours (92.4%). Pain was the most frequent cardinal symptom, along with other symptoms (68/157) or in isolation (33/157), followed by reduced oral intake (32/157) and altered sensorium (24/157). sixty-six patients died within the hospitalisation period. On long-term follow-up, only 8 (5.1%) were surviving. Hyponatraemia (43%), Hypoalbuminaemia (66%), and altered renal function (33.1%) were prevalent. We observed a weak positive correlation between sodium levels and outcome (r = 0.199, P = 0.016) and a strong positive correlation between albumin levels and survival outcomes (r = 0.329, P = 0.000). Patients with normal albumin had a higher chance of survival (odds ratio: 33.1225, 95% confidence interval: 3.415-321.20, P = 0.003). Conclusion: Pain-reduced oral intake and altered sensorium are common emergency symptoms in oncology palliative care. Mortality is high in these patients. Hyponatraemia, hypoalbuminaemia, and deranged renal functions were commonly seen. Normal sodium and albumin levels were associated with higher chances of survival, and the association was strong for serum albumin levels. This may have prognostic utility.

5.
Indian J Crit Care Med ; 28(1): 15-17, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38510766

RESUMEN

The Supreme Court (SC) verdict of 2023 has been welcomed by the medical community in India by those who treat patients with terminal or advanced illnesses. The earlier verdict of the apex court in 2018 was ground-breaking in allowing for advanced directives (ADs) by patients in terms of their preferences at the end of life. However, it was an impractical and lengthy process in the Indian context. The recent verdict has simplified the process of withdrawal of life support, making it more practical. The authority to withdraw life support in dying patients is now also with the treating physician, the hospital, the primary medical board, and the secondary board. This article examines ethical issues related to the specifics of the judgment with respect to those who do not have ADs in India. The present article emphasizes the need for self-regulation, credentialing, and continuing medical education in critical care and palliative medicine. In the absence of these, who will guard the guardians? How to cite this article: Menon MR. Ethics and Medicolegal Aspects of Withdrawal of Treatment in Critical Care Patients without Advanced Directives in India: Who will Guard the Guardians Themselves? Indian J Crit Care Med 2024;28(1):15-17.

6.
Artículo en Inglés | MEDLINE | ID: mdl-37918557

RESUMEN

OBJECTIVE: SETD1A encodes a histone methyltransferase involved in various cell cycle regulatory processes. Loss-of-function SETD1A variants have been associated with numerous neurodevelopmental phenotypes, including intellectual disability and schizophrenia. While the association between rare coding variants in SETD1A and schizophrenia has achieved genome-wide significance by rare variant burden testing, only a few studies have described the psychiatric phenomenology of such individuals in detail. This systematic review and case report aims to characterize the neurodevelopmental and psychiatric phenotypes of SETD1A variant-associated schizophrenia. METHODS: A PubMed search was completed in July 2022 and updated in May 2023. Only studies that reported individuals with a SETD1A variant as well as a primary psychotic disorder were ultimately included. Additionally, another two previously unpublished cases of SETD1A variant-associated psychosis from our own sequencing cohort are described. RESULTS: The search yielded 32 articles. While 15 articles met inclusion criteria, only five provided case descriptions. In total, phenotypic information was available for 11 individuals, in addition to our own two unpublished cases. Our findings suggest that although individuals with SETD1A variant-associated schizophrenia may share a number of common features, phenotypic variability nonetheless exists. Moreover, although such individuals may exhibit numerous other neurodevelopmental features suggestive of the syndrome, their psychiatric presentations appear to be similar to those of general schizophrenia populations. CONCLUSIONS: Loss-of-function SETD1A variants may underlie the development of psychosis in a small percentage of individuals with schizophrenia. Identifying such individuals may become increasingly important, given the potential for advances in precision medicine treatment approaches.


Asunto(s)
Discapacidad Intelectual , Trastornos Psicóticos , Esquizofrenia , Humanos , Predisposición Genética a la Enfermedad , Discapacidad Intelectual/genética , Fenotipo , Trastornos Psicóticos/genética , Trastornos Psicóticos/psicología , Esquizofrenia/genética
7.
Heliyon ; 9(9): e19833, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37810078

RESUMEN

Beliefs without strong supporting evidence (BWSSE) are commonplace, such as religious beliefs and conspiracy theories. The goals of the current study were to identify dimensions of BWSSE in the general public and study how reasons for holding each dimension depend on the strength of the belief. Participants completed a BWSSE questionnaire online, and principal component analysis suggested that the questionnaire captured 6 dimensions of beliefs that range in strength: New Age Spiritual, Traditional Spiritual, Nonconformist, Science, Mythical, and Conspiracy Theory. Mixed-model analyses of variance showed that while high-strength believers in both New Age and Traditional Spiritual shifted their reasons-for-belief away from 'just believe' and towards personal experience, only Traditional Spiritual shifted away from 'just believe' to culture. In contrast, for Conspiracy Theory and Mythical, the dominant reason for belief was media, but for Conspiracy Theory only, there was a shift from media to education/personal research for high-strength believers. This demonstrates that although spiritual beliefs are strengthened by personal experience, conspiracy theory beliefs are strengthened by information gathering. Understanding the source of an existing belief is important for debiasing attempts to move people towards beliefs with strong supporting evidence, including greater acceptance of evidence provided by experts, a likely requirement for negotiating global humanitarian emergencies in the not-so-distant future. Statement of Relevance. Beliefs without strong supporting evidence (BWSSE) have been gaining attention in mainstream society; particularly, the sources of information that may contribute to their formation and resistance to correction. Understanding the source of an existing belief is important for debiasing attempts to move people towards beliefs with strong supporting evidence, including greater acceptance of evidence provided by experts, a likely requirement for negotiating global humanitarian emergencies in the not-so-distant future.

8.
JMIR Serious Games ; 11: e43904, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37027183

RESUMEN

BACKGROUND: Major depressive disorder (MDD) is the leading cause of global disability; however, the existing treatments do not always address cognitive dysfunction-a core feature of MDD. Immersive virtual reality (VR) has emerged as a promising modality to enhance the real-world effectiveness of cognitive remediation. OBJECTIVE: This study aimed to develop the first prototype VR cognitive remediation program for MDD ("bWell-D"). This study gathered qualitative data from end users early in the design process to enhance its efficacy and feasibility in clinical settings. METHODS: Semistructured end-user interviews were conducted remotely (n=15 patients and n=12 clinicians), assessing the participants' perceptions and goals for a VR cognitive remediation program. Video samples of bWell-D were also shared to obtain feedback regarding the program. The interviews were transcribed, coded, and analyzed via thematic analysis. RESULTS: End users showed an optimistic outlook toward VR as a treatment modality, and perceived it as a novel approach with the potential of having multiple applications. The participants expressed a need for an engaging VR treatment that included realistic and multisensorial settings and activities, as well as customizable features. Some skepticism regarding its effectiveness was also reported, especially when the real-world applications of the practiced skills were not made explicit, as well as some concerns regarding equipment accessibility. A home-based or hybrid (ie, home and clinic) treatment modality was preferred. CONCLUSIONS: Patients and clinicians considered bWell-D interesting, acceptable, and potentially feasible, and provided suggestions to enhance its real-world applicability. The inclusion of end-user feedback is encouraged when developing future VR programs for clinical purposes.

9.
Eur Arch Psychiatry Clin Neurosci ; 273(4): 811-817, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35338378

RESUMEN

This article provides an overview and retrospective on metacognitive training for psychosis (MCT), which first appeared approximately 2 decades ago. We recount how our empirical understanding of psychosis at that time led to the first preliminary version of the program. We describe setbacks and challenges that led to major changes, including revisions to existing modules (e.g., more focus on metacognitive variables, particularly on decision confidence as one of the primary targets of treatment) and the creation of new modules addressing mood, as well as attempts to improve sustainability of effects via homework exercises and a smartphone app ( www.uke.de/mct_app ). We have also enhanced dissemination efforts by creating new culturally sensitive language versions and facilitating low-threshold training through e-learning courses ( www.uke.de/e-mct ). Finally, we discuss several meta-analyses on the efficacy of MCT that have been published over the last decade. While reviews were initially inconsistent, possibly reflecting the insufficient statistical power and lower design quality of the first MCT studies, more recent meta-analyses have confirmed the efficacy of MCT on positive symptoms, insight, and cognitive biases, which has led to the inclusion of MCT in some national treatment guidelines for schizophrenia.


Asunto(s)
Terapia Cognitivo-Conductual , Metacognición , Trastornos Psicóticos , Esquizofrenia , Humanos , Estudios Retrospectivos , Trastornos Psicóticos/terapia , Esquizofrenia/terapia , Esquizofrenia/diagnóstico , Resultado del Tratamiento
10.
Cogn Neuropsychiatry ; 27(6): 411-429, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35930314

RESUMEN

Introduction: Relationships between subjective cognitive functioning (SCF), objective cognitive functioning (OCF), and depressive symptoms are poorly understood in treatment-resistant psychosis (TRP). This study (a) compares SCF in TRP using positively and negatively worded scales, (b) assess these scales' accuracy, and (c) explores the association between these scales and depressive symptoms. We hypothesised that both SCF scales would be highly correlated, minimally associated with OCF, and similarly associated with depressive symptoms. Methods: Archival clinical data from 52 TRP inpatients was utilised. OCF composite scores were derived from a broad neuropsychological battery. SCF was assessed using the norm-referenced PROMIS 2.0 Cognitive Abilities (positively worded) and Concerns (negatively worded) subscales. A depressive symptom score was derived from the Positive and Negative Syndrome Scale. Results: SCF ratings were higher in patients than OCF. There was a small but significant correlation between PROMIS subscales (r = .30). Neither PROMIS subscale was associated with OCF (r = -.11, r = .01). Depressive symptoms were correlated with the positively (r = -.29) but not negatively worded scale (r = -.13). Conclusion: Individuals with TRP inaccurately rate their cognitive functioning and tend to overestimate their ability. Positively and negatively worded SCF scales associate variably with depressive symptoms, indicating they may not be used interchangeably in TRP.


Asunto(s)
Trastornos del Conocimiento , Trastornos Psicóticos , Cognición , Trastornos del Conocimiento/psicología , Depresión/diagnóstico , Humanos , Pruebas Neuropsicológicas , Trastornos Psicóticos/psicología
11.
Psychiatry Res Neuroimaging ; 323: 111472, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35405574

RESUMEN

Delusions in schizophrenia are false beliefs that are assigned certainty and not afforded the scrutiny that normally gives rise to doubt, even under conditions of weak evidence. The goal of the current functional magnetic resonance imaging (fMRI) study is to identify the brain network(s) involved in gathering information under conditions of weak evidence, in people with schizophrenia experiencing delusions. fMRI activity during probabilistic reasoning in people with schizophrenia experiencing delusions (n = 29) compared to people with schizophrenia not experiencing delusions (n = 41) and healthy controls (n = 41) was observed when participants made judgments based on evidence that weakly or strongly matched (or mismatched) with the focal hypothesis. A brain network involved in visual attention was strongly elicited for conditions of weak evidence for healthy controls and patients not experiencing delusions, but this increase was absent for patients experiencing delusions. This suggests that the state associated with delusions manifests in fMRI as reduced activity in an early visual attentional process whereby weak evidence is incorrectly stamped as conclusive, manifestating as a feeling of fluency and misplaced certainty, short-circuiting the search for evidence, and providing a candidate neural process for 'seeding' delusions.


Asunto(s)
Esquizofrenia , Encéfalo/diagnóstico por imagen , Deluciones/diagnóstico por imagen , Deluciones/etiología , Humanos , Juicio , Imagen por Resonancia Magnética/métodos , Esquizofrenia/complicaciones , Esquizofrenia/diagnóstico por imagen
12.
Schizophr Res Cogn ; 28: 100230, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35242604

RESUMEN

Severe cognitive impairments and cognitive distortions are core to schizophrenia-spectrum disorders (SSDs) and are associated with deteriorated social functioning. Despite well-established efficacy of group psychosocial therapies targeting cognitive health in SSDs, dissemination of these programs remains limited. Remote delivery offers a promising strategy for increasing the programs' accessibility. Yet, little research has evaluated group therapies for cognitive health delivered in this way. Thus, we aimed to assess, from participants' and therapists' perspectives, the feasibility, acceptability, as well as levels and process of engagement in a videoconference delivery of group psychosocial therapies for SSD patients' cognitive health. Participants, outpatients, attended Action Based Cognitive Remediation or Metacognitive Training, both adapted for videoconference. Then, participants and therapists completed post-therapy questionnaires. Of the 28 participants attending at least one session, 75% completed more than half of sessions and seven dropped out. Technology did not appear to significantly hinder participation in the programs. All completing participants reported a positive experience with therapy, 67% were not bothered by the distance from the therapist, and 77% trusted that the information shared was kept confidential. Therapist-rated levels of attention M = 7.5/9 (SD = 1.04), participation M = 6.91/9 (SD = 1.32), and social interactions M = 5.31/9 (SD = 1.96) were satisfactory. Nonetheless, participants indicated that they would have appreciated more social interactions with group members. These positive results validate the earliest stage in the implementation process for remote group therapies targeting cognitive health in SSDs. Remote delivery promises to improve access to therapies targeting cognitive health and, ultimately, facilitate functional recovery for SSD patients.

13.
Schizophrenia (Heidelb) ; 8(1): 14, 2022 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-35249112

RESUMEN

Many individuals living with severe mental illness, such as schizophrenia, present cognitive deficits and reasoning biases negatively impacting clinical and functional trajectories. Remote cognitive assessment presents many opportunities for advancing research and treatment but has yet to be widely used in psychiatric populations. We conducted a scoping review of remote cognitive assessment in severe mental illness to provide an overview of available measures and guide best practices. Overall, 34 studies (n = 20,813 clinical participants) were reviewed and remote measures, psychometrics, facilitators, barriers, and future directions were synthesized using a logic model. We identified 82 measures assessing cognition in severe mental illness across 11 cognitive domains and four device platforms. Remote measures were generally comparable to traditional versions, though psychometric properties were infrequently reported. Facilitators included standardized procedures and wider recruitment, whereas barriers included imprecise measure adaptations, technology inaccessibility, low patient engagement, and poor digital literacy. Our review identified several remote cognitive measures in psychiatry across all cognitive domains. However, there is a need for more rigorous validation of these measures and consideration of potentially influential factors, such as sex and gender. We provide recommendations for conducting remote cognitive assessment in psychiatry and fostering high-quality research using digital technologies.

15.
Br J Clin Pharmacol ; 88(3): 1369-1372, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34427944

RESUMEN

Human leukocyte antigens (HLA) have been linked to adverse drug reactions. Generally, HLA association is phenotype specific and is related to either liver or skin injury. HLA-A*13:01 has been linked to dapsone-induced severe cutaneous drug reactions and its role in drug-induced liver injury (DILI) is unclear. In our series, all of the four patients with immunoallergic dapsone DILI were carrying HLA-B*13:01 compared to its prevalence of 1-12% among Indians. HLA-B*13:01 plays a role not only in dapsone-induced severe cutaneous adverse reaction (SCAR) but also in dapsone-induced liver injury with immunoallergic features and highlights the role of adaptive immune response in the pathogenesis of both liver and skin injury and associated other organ involvement.


Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Enfermedad Hepática Inducida por Sustancias y Drogas , Enfermedad Hepática Inducida por Sustancias y Drogas/epidemiología , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Dapsona/efectos adversos , Antígenos HLA/genética , Antígenos HLA-B/genética , Humanos
16.
Schizophr Bull Open ; 3(1): sgac050, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39144798

RESUMEN

Background: While advances in the field of functional magnetic resonance imaging (fMRI) provide new opportunities to study brain networks underlying the experience of hallucinations in psychosis, there are methodological challenges unique to symptom-capture studies. Study Design: We extracted brain networks activated during hallucination-capture for schizophrenia patients when fMRI data collected from two sites was merged (combined N = 27). A multidimensional analysis technique was applied, which would allow separation of brain networks involved in the hallucinatory experience itself from those involved in the motor response of indicating the beginning and end of the perceived hallucinatory experience. To avoid reverse inference when attributing a function (e.g., a hallucination) to anatomical regions, it was required that longer hallucinatory experiences produce extended brain responses relative to shorter. Study Results: For radio-speech sound files, an auditory perception brain network emerged, and displayed speech-duration-dependent hemodynamic responses (HDRs). However, in the hallucination-capture blocks, no network showed hallucination-duration-dependent HDRs, but a retrieved network that was anatomically classified as motor response emerged. Conclusions: During symptom capture of hallucinations during fMRI, no HDR showed duration dependence, but a brain network anatomically matching the motor response network was retrieved. Previous reports on brain networks detected by fMRI during hallucination capture are reviewed in this context; namely, that the brain networks interpreted as involved in hallucinations may in fact be involved only in the motor response indicating the onset of the hallucination.

17.
Cortex ; 145: 131-144, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34717270

RESUMEN

Hallucinatory experiences (HEs) can be pronounced in psychosis, but similar experiences also occur in nonclinical populations. Cognitive mechanisms hypothesized to underpin HEs include dysfunctional source monitoring, heightened signal detection, and impaired attentional processes. Using data from an international multisite study on non-clinical participants (N = 419), we described the overlap between two sets of variables - one measuring cognition and the other HEs - at the level of individual items. We used a three-step method to extract and examine item-specific signal, which is typically obscured when summary scores are analyzed using traditional methodologies. The three-step method involved: (1) constraining variance in cognition variables to that which is predictable from HE variables, followed by dimension reduction, (2) determining reliable HE items using split-halves and permutation tests, and (3) selecting cognition items for interpretation using a leave-one-out procedure followed by repetition of Steps 1 and 2. The results showed that the overlap between HEs and cognition variables can be conceptualized as bi-dimensional, with two distinct mechanisms emerging as candidates for separate pathways to the development of HEs: HEs involving perceptual distortions on one hand (including voices), underpinned by a low threshold for signal detection in cognition, and HEs involving sensory overload on the other hand, underpinned by reduced laterality in cognition. We propose that these two dimensions of HEs involving distortions/liberal signal detection, and sensation overload/reduced laterality may map onto psychosis-spectrum and dissociation-spectrum anomalous experiences, respectively.


Asunto(s)
Alucinaciones , Trastornos Psicóticos , Atención , Cognición , Humanos , Análisis Multivariante
18.
Schizophr Res ; 216: 302-309, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31839549

RESUMEN

Cognitive biases affecting evidence integration contribute to delusions and delusional ideation in the psychosis continuum. In previously published work we observed hyperactivity in a visual attention network (VsAN) during confirmatory evidence integration, and hypoactivity in a cognitive evaluation network (CEN) during disconfirmatory evidence integration in schizophrenia patients with delusions, suggesting that a task-specific imbalance of these networks may contribute to delusion maintenance. In the current study, we investigated whether patterns of aberrant functional connectivity observed in past work were associated with delusional ideation in 41 healthy individuals by examining associations between cognitive biases, subclinical schizotypal traits, and functional brain activity during evidence integration. Behaviourally, we replicated positive associations between schizotypal traits and cognitive biases and further showed that this association was driven by delusional ideation specifically. Constrained principal component analysis for fMRI (fMRI-CPCA) revealed recruitment of the brain networks observed in our previous clinical and non-clinical evidence integration studies: default-mode network (DMN); cognitive evaluation network (CEN); and visual attention (VsAN) network. Moreover, as with clinically-significant delusions, delusional ideation was associated with decreased CEN activity during the processing of disconfirmatory evidence and increased VsAN activity during the processing of confirmatory evidence. These findings suggest that this altered pattern of activation across networks during evidence integration may underlie delusional ideation and delusions in the psychosis continuum.


Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Encéfalo/diagnóstico por imagen , Deluciones , Humanos , Trastornos Psicóticos/complicaciones , Trastornos Psicóticos/diagnóstico por imagen , Esquizofrenia/complicaciones , Esquizofrenia/diagnóstico por imagen , Pensamiento
19.
Brain Cogn ; 138: 103631, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31835145

RESUMEN

Functional magnetic resonance imaging (fMRI)5 studies on lexical decision (LD)6 attempting to isolate the brain network underlying access to lexical representations can be confounded by attentional and response processes. However, manipulating the "wordlikeness" of the LD stimuli can facilitate functional interpretation of each emerging brain network, providing principles for separation of attentional demand from linguistic processing. This is because activation of difficult-to-access lexical representations (for obscure real words), and avoidance of interfering word properties (for wordlike non-words), are both generally attentionally demanding. Therefore, congruent patterns of activation would be predicted for general-attention-responsive networks, but opposing patterns for language-responsive networks. 59 healthy adults performed a LD task, and multidimensional functional connectivity analysis was used to extract three functional brain networks. A linguistic processing network (LPN) was separated from attention/response networks anatomically (LPN included Broca's and Wernicke's areas), but also temporally by showing reduced activation for the most attentionally demanding condition (i.e., wordlike non-words). This demonstrated that during LD in fMRI a network involved in linguistic processing can be disentangled from attention- and response-specific networks, using a combination of experimental design and multidimensional analysis methods.


Asunto(s)
Corteza Cerebral/fisiología , Conectoma , Toma de Decisiones/fisiología , Lenguaje , Red Nerviosa/fisiología , Adulto , Corteza Cerebral/diagnóstico por imagen , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagen , Adulto Joven
20.
Schizophr Bull ; 46(1): 175-183, 2020 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-31050762

RESUMEN

Integrating evidence that contradicts a belief is a fundamental aspect of belief revision and is closely linked to delusions in schizophrenia. In a previous functional magnetic resonance imaging (fMRI) study on healthy individuals, we identified functional brain networks underlying evidence integration as visual attention network (VsAN; dorsal anterior cingulate cortex, insula, occipital regions), default-mode network (DMN), and cognitive evaluation network (CEN; orbitofrontal cortex, inferior frontal gyrus, parietal cortex). In the current clinical fMRI study, we compared network-based activity during evidence integration between healthy controls (n = 41), nondelusional (n = 37), and delusional (n = 33) patients with schizophrenia, and related this activity to cognitive processing involved in evidence integration measured outside the scanner. Task-induced coordinated activation was measured using group-constrained principal component analysis for fMRI. Increased VsAN activation, reduced DMN deactivation, and reduced CEN activation were observed for schizophrenia, with this pattern being most pronounced for the delusional group. Importantly, poor evidence integration comprehensively measured outside the scanner was significantly associated with increased VsAN activation and reduced DMN deactivation when processing confirmatory evidence, and with reduced CEN activation when processing disconfirmatory evidence. This is the first comprehensive study of the functional brain networks associated with evidence integration in schizophrenia and highlights how an imbalance of functional brain networks responding to confirmatory and disconfirmatory evidence may underlie delusions in schizophrenia.


Asunto(s)
Corteza Cerebral/fisiopatología , Conectoma , Deluciones/fisiopatología , Red Nerviosa/fisiopatología , Reconocimiento Visual de Modelos/fisiología , Trastornos Psicóticos/fisiopatología , Esquizofrenia/fisiopatología , Adulto , Corteza Cerebral/diagnóstico por imagen , Deluciones/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Red Nerviosa/diagnóstico por imagen , Análisis de Componente Principal , Desempeño Psicomotor/fisiología , Trastornos Psicóticos/diagnóstico por imagen , Esquizofrenia/diagnóstico por imagen
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