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1.
Appl Opt ; 63(5): 1241-1246, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38437303

RESUMO

We demonstrate a Sagnac-interferometer-based multiwavelength fiber laser with an intensity-dependent loss (IDL) mechanism in the L-band region using a semiconductor optical amplifier (SOA) as the gain medium. The IDL mechanism flattens and stabilizes the multiwavelength spectrum. We also investigate the effect of rotation angles of polarization controllers (PCs) at different polarization devices on multiwavelength performance. At best settings, 31 lasing lines within 3 dB uniformity were generated with an extinction ratio (ER) of 17 dB. Adjusting the half-wave plate of PC1 and PC2 from 0° to 90° shifted the multiwavelength output by 0.01 nm and 0.072 nm, respectively. PC2 adjustment also affects the multiwavelength flatness as compared to PC1. Furthermore, the number of lasing lines and the ER were directly influenced by the SOA current.

2.
Aust N Z J Psychiatry ; : 48674241235849, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38470085

RESUMO

OBJECTIVE: Auditory hallucinations (hearing voices) have been associated with a range of altered cognitive functions, pertaining to signal detection, source-monitoring, memory, inhibition and language processes. Yet, empirical results are inconsistent. Despite this, several theoretical models of auditory hallucinations persist, alongside increasing emphasis on the utility of a multidimensional framework. Thus, clarification of current evidence across the broad scope of proposed mechanisms is warranted. METHOD: A systematic search of the Web of Science, PubMed and Scopus databases was conducted. Records were screened to confirm the use of an objective behavioural cognitive task, and valid measurement of hallucinations specific to the auditory modality. RESULTS: Auditory hallucinations were primarily associated with difficulties in perceptual decision-making (i.e. reduced sensitivity/accuracy for signal-noise discrimination; liberal responding to ambiguity), source-monitoring (i.e. self-other and temporal context confusion), working memory and language function (i.e. reduced verbal fluency). Mixed or limited support was observed for perceptual feature discrimination, imagery vividness/illusion susceptibility, source-monitoring for stimulus form and spatial context, recognition and recall memory, executive functions (e.g. attention, inhibition), emotion processing and language comprehension/hemispheric organisation. CONCLUSIONS: Findings were considered within predictive coding and self-monitoring frameworks. Of concern was the portion of studies which - despite offering auditory-hallucination-specific aims and inferences - employed modality-general measures, and/or diagnostic-based contrasts with psychologically healthy individuals. This review highlights disparities within the literature between theoretical conceptualisations of auditory hallucinations and the body of rigorous empirical evidence supporting such inferences. Future cognitive investigations, beyond the schizophrenia-spectrum, which explicitly define and measure the timeframe and sensory modality of hallucinations, are recommended.

3.
Cells ; 13(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38334656

RESUMO

Background: Postoperative cognitive dysfunction (POCD) is a common disorder after general anesthesia in elderly patients, the precise mechanisms of which remain unclear. Methods: We investigated the effect of isoflurane with or without dantrolene pretreatment on intracellular calcium concentration ([Ca2+]i), reactive oxygen species (ROS) production, cellular lactate dehydrogenase (LDH) leak, calpain activity, and cognitive function using the Morris water maze test of young (3 months), middle-aged (12-13 months), and aged (24-25 months) C57BL6/J mice. Results: Aged cortical and hippocampal neurons showed chronically elevated [Ca2+]i compared to young neurons. Furthermore, aged hippocampal neurons exhibited higher ROS production, increased LDH leak, and elevated calpain activity. Exposure to isoflurane exacerbated these markers in aged neurons, contributing to increased cognitive deficits in aged mice. Dantrolene pretreatment reduced [Ca2+]i for all age groups and prevented or significantly mitigated the effects of isoflurane on [Ca2+]i, ROS production, LDH leak, and calpain activity in aged neurons. Dantrolene also normalized or improved age-associated cognitive deficits and mitigated the cognitive deficits caused by isoflurane. Conclusions: These findings suggest that isoflurane-induced cytotoxicity and cognitive decline in aging are linked to disruptions in neuronal intracellular processes, highlighting the reduction of [Ca2+]i as a potential therapeutic intervention.


Assuntos
Anestesia , Anestésicos Inalatórios , Disfunção Cognitiva , Isoflurano , Fármacos Neuroprotetores , Camundongos , Humanos , Animais , Pessoa de Meia-Idade , Idoso , Isoflurano/efeitos adversos , Anestésicos Inalatórios/toxicidade , Fármacos Neuroprotetores/uso terapêutico , Calpaína , Espécies Reativas de Oxigênio/efeitos adversos , Dantroleno/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/induzido quimicamente , Camundongos Endogâmicos C57BL , Neurônios
4.
Mol Psychiatry ; 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38243074

RESUMO

Abnormalities in functional brain networks (functional connectome) are increasingly implicated in people at Clinical High Risk for Psychosis (CHR-P). Intranasal oxytocin, a potential novel treatment for the CHR-P state, modulates network topology in healthy individuals. However, its connectomic effects in people at CHR-P remain unknown. Forty-seven men (30 CHR-P and 17 healthy controls) received acute challenges of both intranasal oxytocin 40 IU and placebo in two parallel randomised, double-blind, placebo-controlled cross-over studies which had similar but not identical designs. Multi-echo resting-state fMRI data was acquired at approximately 1 h post-dosing. Using a graph theoretical approach, the effects of group (CHR-P vs healthy control), treatment (oxytocin vs placebo) and respective interactions were tested on graph metrics describing the topology of the functional connectome. Group effects were observed in 12 regions (all pFDR < 0.05) most localised to the frontoparietal network. Treatment effects were found in 7 regions (all pFDR < 0.05) predominantly within the ventral attention network. Our major finding was that many effects of oxytocin on network topology differ across CHR-P and healthy individuals, with significant interaction effects observed in numerous subcortical regions strongly implicated in psychosis onset, such as the thalamus, pallidum and nucleus accumbens, and cortical regions which localised primarily to the default mode network (12 regions, all pFDR < 0.05). Collectively, our findings provide new insights on aberrant functional brain network organisation associated with psychosis risk and demonstrate, for the first time, that oxytocin modulates network topology in brain regions implicated in the pathophysiology of psychosis in a clinical status (CHR-P vs healthy control) specific manner.

5.
bioRxiv ; 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38260485

RESUMO

As the primary Ca 2+ release channel in skeletal muscle sarcoplasmic reticulum (SR), mutations in the type 1 ryanodine receptor (RyR1) or its binding partners underlie a constellation of muscle disorders, including malignant hyperthermia (MH). In patients with MH mutations, exposure to triggering drugs such as the halogenated volatile anesthetics biases RyR1 to an open state, resulting in uncontrolled Ca 2+ release, sarcomere tension and heat production. Restoration of Ca 2+ into the SR also consumes ATP, generating a further untenable metabolic load. When anesthetizing patients with known MH mutations, the non-triggering intravenous general anesthetic propofol is commonly substituted for triggering anesthetics. Evidence of direct binding of anesthetic agents to RyR1 or its binding partners is scant, and the atomic-level interactions of propofol with RyR1 are entirely unknown. Here, we show that propofol decreases RyR1 opening in heavy SR vesicles and planar lipid bilayers, and that it inhibits activator-induced Ca 2+ release from SR in human skeletal muscle. In addition to confirming direct binding, photoaffinity labeling using m- azipropofol (AziP m ) revealed several putative propofol binding sites on RyR1. Prediction of binding affinity by molecular dynamics simulation suggests that propofol binds at least one of these sites at clinical concentrations. These findings invite the hypothesis that in addition to propofol not triggering MH, it may also be protective against MH by inhibiting induced Ca 2+ flux through RyR1.

6.
Psychol Med ; 54(5): 993-1003, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37845827

RESUMO

BACKGROUND: Hippocampal hyperperfusion has been observed in people at Clinical High Risk for Psychosis (CHR), is associated with adverse longitudinal outcomes and represents a potential treatment target for novel pharmacotherapies. Whether cannabidiol (CBD) has ameliorative effects on hippocampal blood flow (rCBF) in CHR patients remains unknown. METHODS: Using a double-blind, parallel-group design, 33 CHR patients were randomized to a single oral 600 mg dose of CBD or placebo; 19 healthy controls did not receive any drug. Hippocampal rCBF was measured using Arterial Spin Labeling. We examined differences relating to CHR status (controls v. placebo), effects of CBD in CHR (placebo v. CBD) and linear between-group relationships, such that placebo > CBD > controls or controls > CBD > placebo, using a combination of hypothesis-driven and exploratory wholebrain analyses. RESULTS: Placebo-treated patients had significantly higher hippocampal rCBF bilaterally (all pFWE<0.01) compared to healthy controls. There were no suprathreshold effects in the CBD v. placebo contrast. However, we found a significant linear relationship in the right hippocampus (pFWE = 0.035) such that rCBF was highest in the placebo group, lowest in controls and intermediate in the CBD group. Exploratory wholebrain results replicated previous findings of hyperperfusion in the hippocampus, striatum and midbrain in CHR patients, and provided novel evidence of increased rCBF in inferior-temporal and lateral-occipital regions in patients under CBD compared to placebo. CONCLUSIONS: These findings suggest that hippocampal blood flow is elevated in the CHR state and may be partially normalized by a single dose of CBD. CBD therefore merits further investigation as a potential novel treatment for this population.


Assuntos
Canabidiol , Transtornos Psicóticos , Humanos , Canabidiol/farmacologia , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/tratamento farmacológico , Hipocampo/diagnóstico por imagem , Corpo Estriado , Método Duplo-Cego
7.
J Laryngol Otol ; 138(4): 436-442, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37212024

RESUMO

OBJECTIVE: To compare supraglottoplasty versus non-surgical treatment in children with laryngomalacia and mild, moderate and severe obstructive sleep apnoea. METHODS: Patients were classified based on their obstructive apnoea hypopnoea index on initial polysomnogram, which was compared to their post-treatment polysomnogram. RESULTS: Eighteen patients underwent supraglottoplasty, and 12 patients had non-surgical treatment. The average obstructive apnoea hypopnoea index after supraglottoplasty fell by 12.68 events per hour (p = 0.0039) in the supraglottoplasty group and 3.3 events per hour (p = 0.3) in the non-surgical treatment group. Comparison of the change in obstructive apnoea hypopnoea index in the surgical versus non-surgical groups did not meet statistical significance (p = 0.09). CONCLUSION: All patients with laryngomalacia and obstructive sleep apnoea had a statistically significant improvement in obstructive apnoea hypopnoea index after supraglottoplasty irrespective of obstructive sleep apnoea severity, whereas patients who received non-surgical treatment had more variable and unpredictable results. Direct comparison of the change between the two groups did not find supraglottoplasty to be superior to non-surgical treatment. Larger prospective studies are recommended.


Assuntos
Laringomalácia , Apneia Obstrutiva do Sono , Criança , Humanos , Laringomalácia/complicações , Laringomalácia/cirurgia , Estudos Prospectivos , Resultado do Tratamento , Apneia Obstrutiva do Sono/cirurgia , Polissonografia
8.
Healthc Manage Forum ; 37(1): 26-29, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37459444

RESUMO

This article underscores the significance of cyberdefences and response processes in healthcare, highlighting their contribution to cyber resilience through adherence to industry best practices. It emphasizes the value of hypothetical scenarios as a common practice in the field to validate the effectiveness of cyber resilient actions, systems, processes, and decision-making in the face of various cyberthreats. Focusing on the ransomware threat, the provided scenario examines its impact on healthcare systems and frontline support staff, while highlighting the time-sensitive challenges faced by response teams striving to restore essential services. Furthermore, it suggests replicating such analyses with key hospital personnel to precisely assess the impact of other types of cyberthreats, such as those originating from malicious insiders or technical data breaches facilitated through social engineering attacks. By doing so, healthcare organizations can develop comprehensive and cyber resilient responses to safeguard their operations.


Assuntos
Resiliência Psicológica , Humanos , Segurança Computacional , Organizações , Atenção à Saúde
9.
J Biol Chem ; 299(8): 104992, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37392848

RESUMO

Malignant hyperthermia susceptibility (MHS) is an autosomal dominant pharmacogenetic disorder that manifests as a hypermetabolic state when carriers are exposed to halogenated volatile anesthetics or depolarizing muscle relaxants. In animals, heat stress intolerance is also observed. MHS is linked to over 40 variants in RYR1 that are classified as pathogenic for diagnostic purposes. More recently, a few rare variants linked to the MHS phenotype have been reported in CACNA1S, which encodes the voltage-activated Ca2+ channel CaV1.1 that conformationally couples to RyR1 in skeletal muscle. Here, we describe a knock-in mouse line that expresses one of these putative variants, CaV1.1-R174W. Heterozygous (HET) and homozygous (HOM) CaV1.1-R174W mice survive to adulthood without overt phenotype but fail to trigger with fulminant malignant hyperthermia when exposed to halothane or moderate heat stress. All three genotypes (WT, HET, and HOM) express similar levels of CaV1.1 by quantitative PCR, Western blot, [3H]PN200-110 receptor binding and immobilization-resistant charge movement densities in flexor digitorum brevis fibers. Although HOM fibers have negligible CaV1.1 current amplitudes, HET fibers have similar amplitudes to WT, suggesting a preferential accumulation of the CaV1.1-WT protein at triad junctions in HET animals. Never-the-less both HET and HOM have slightly elevated resting free Ca2+ and Na+ measured with double barreled microelectrode in vastus lateralis that is disproportional to upregulation of transient receptor potential canonical (TRPC) 3 and TRPC6 in skeletal muscle. CaV1.1-R174W and upregulation of TRPC3/6 alone are insufficient to trigger fulminant malignant hyperthermia response to halothane and/or heat stress in HET and HOM mice.


Assuntos
Halotano , Resposta ao Choque Térmico , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta , Hipertermia Maligna , Animais , Camundongos , Cálcio/metabolismo , Halotano/farmacologia , Resposta ao Choque Térmico/genética , Hipertermia Maligna/genética , Hipertermia Maligna/metabolismo , Hipertermia Maligna/patologia , Músculo Esquelético/metabolismo , Mutação , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/genética
10.
Neuroimage ; 278: 120280, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37460012

RESUMO

The circular inference (CI) computational model assumes a corruption of sensory data by prior information and vice versa, leading at the extremes to 'see what we expect' (through prior amplification) and/or to 'expect what we see' (through sensory amplification). Although a CI mechanism has been reported in a schizophrenia population, it has not been investigated in individuals experiencing psychosis-like experiences, such as people with high schizotypy traits. Furthermore, the neurobiological basis of CI, such as the link between hierarchical amplifications, excitatory neurotransmission, and resting state functional connectivity (RSFC), remains untested. The participants included in the present study consisted of a subsample of those recruited in a study previously published by our group, Kozhuharova et al. (2021b). We included 36 participants with High (n=18) and Low (n=18) levels of schizotypy who completed a probabilistic reasoning task (the Fisher task) for which individual confidence levels were obtained and fitted to the CI model. Participants also underwent a 1H-Magnetic Resonance Spectroscopy (MRS) scan to measure medial prefrontal cortex (mPFC) glutamate metabolite levels, and a functional Magnetic Resonance Imaging (fMRI) scan to measure RSFC of the medial prefrontal cortex (mPFC). People with high levels of schizotypy exhibited changes in CI parameters, altered cortical excitatory neurotransmission and RSFC that were all associated with sensory amplification. Our findings capture a multimodal signature of CI that is observable in people early in the psychosis spectrum.


Assuntos
Ácido Glutâmico , Transtorno da Personalidade Esquizotípica , Humanos , Ácido Glutâmico/metabolismo , Transtorno da Personalidade Esquizotípica/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Córtex Pré-Frontal
11.
J Psychopharmacol ; 37(5): 510-519, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37070169

RESUMO

BACKGROUND: Childhood trauma (CT) has been linked to increased risk for mental illness in adulthood. Although work in experimental animals has shown that early life stressors can affect inhibitory and excitatory neurotransmission in adult rodents, with possible excitotoxic effects on local grey matter volumes (GMV), the neurobiological mechanisms that mediate this relationship in humans remain poorly understood. AIM: To examine glutamate and gamma-aminobutyric acid (GABA) metabolite concentrations and potential excitotoxic effects on GMV, in adults who experienced CT. METHODS: Fifty-six young adults (Mage = 20.41) were assigned to High CT (n = 29) and Low CT (n = 27) groups (by using the CT questionnaire) and underwent magnetic resonance spectroscopy (1H-MRS) to measure temporal lobe metabolite concentrations and volumetric imaging to measure GMV. RESULTS: Glutamate concentrations did not differ between groups; however, relative to the Low CT group, participants in the High CT group had reduced GABA concentrations in the left superior temporal gyrus (STG) voxel. Furthermore, logistic regression showed that participants with low left STG GABA concentrations and low left STG volumes were significantly more likely to be in the high CT group. CONCLUSIONS: This study provides the first evidence that both low GABA concentrations and its interaction with GMV in the left STG are associated with high levels of CT and suggest that altered inhibitory neurotransmission/metabolism may be linked to a lower GMV in the left STG in adults who experienced CT. Future studies are warranted to establish if utilizing these measures can stratify clinical high-risk and predict future clinical outcomes in high CT individuals.


Assuntos
Experiências Adversas da Infância , Neuroquímica , Humanos , Adulto Jovem , Adulto , Imageamento por Ressonância Magnética , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/metabolismo , Lobo Temporal/patologia , Ácido Glutâmico/metabolismo , Ácido gama-Aminobutírico/metabolismo
12.
Front Psychiatry ; 14: 1092213, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36970257

RESUMO

Introduction: The impact of the clinical high-risk for psychosis (CHR-P) construct is dependent on accurately predicting outcomes. Individuals with brief limited intermittent psychotic symptoms (BLIPS) have higher risk of developing a first episode of psychosis (FEP) compared to individuals with attenuated psychotic symptoms (APS). Supplementing subgroup stratification with information from candidate biomarkers based on neurobiological parameters, such as resting-state, regional cerebral blood flow (rCBF), may help refine risk estimates. Based on previous evidence, we hypothesized that individuals with BLIPS would exhibit increased rCBF compared to APS in key regions linked to dopaminergic pathways. Methods: Data from four studies were combined using ComBat (to account for between-study differences) to analyse rCBF in 150 age- and sex-matched subjects (n = 30 healthy controls [HCs], n = 80 APS, n = 20 BLIPS and n = 20 FEP). Global gray matter (GM) rCBF was examined in addition to region-of-interest (ROI) analyses in bilateral/left/right frontal cortex, hippocampus and striatum. Group differences were assessed using general linear models: (i) alone; (ii) with global GM rCBF as a covariate; (iii) with global GM rCBF and smoking status as covariates. Significance was set at p < 0.05. Results: Whole-brain voxel-wise analyses and Bayesian ROI analyses were also conducted. No significant group differences were found in global [F(3,143) = 1,41, p = 0.24], bilateral frontal cortex [F(3,143) = 1.01, p = 0.39], hippocampus [F(3,143) = 0.63, p = 0.60] or striatum [F(3,143) = 0.52, p = 0.57] rCBF. Similar null findings were observed in lateralized ROIs (p > 0.05). All results were robust to addition of covariates (p > 0.05). No significant clusters were identified in whole-brain voxel-wise analyses (p > 0.05FWE). Weak-to-moderate evidence was found for an absence of rCBF differences between APS and BLIPS in Bayesian ROI analyses. Conclusion: On this evidence, APS and BLIPS are unlikely to be neurobiologically distinct. Due to this and the weak-to-moderate evidence for the null hypothesis, future research should investigate larger samples of APS and BLIPS through collaboration across large-scale international consortia.

13.
Brain Sci ; 13(2)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36831783

RESUMO

Recent studies suggest that transcranial direct current stimulation (tDCS) applied over the prefrontal cortex (PFaC) may enhance episodic memory ability. As such, there is ongoing interest in the therapeutic potential of this technique in age-related memory decline. At the same time, the findings are not yet conclusive regarding the magnitude of this effect, and assumptions regarding underlying brain mechanisms of stimulation-induced changes in behaviour are yet to be tested in detail. Here, we evaluated the effect of tDCS over left PFC on verbal episodic memory in young adults. Two separate randomized, double-blind, sham-controlled experiments were carried out using (1) incidental learning followed by a recognition test and (2) intentional learning followed by a free recall. In both studies, participants performed a learning task with active or sham tDCS during the encoding period, followed by retrieval tasks on the same day and the next day. The results suggest that, contrary to expectations, active tDCS did not enhance memory performance relative to sham tDCS. Possible reasons behind the lack of enhancement effects are discussed, including the possibility that memory enhancement effects of tDCS may be smaller than first thought. Scientific practices that could improve estimation accuracy in the field are also discussed.

14.
Science ; 379(6633): eabg2752, 2023 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-36795805

RESUMO

The induction of proinflammatory T cells by dendritic cell (DC) subtypes is critical for antitumor responses and effective immune checkpoint blockade (ICB) therapy. Here, we show that human CD1c+CD5+ DCs are reduced in melanoma-affected lymph nodes, with CD5 expression on DCs correlating with patient survival. Activating CD5 on DCs enhanced T cell priming and improved survival after ICB therapy. CD5+ DC numbers increased during ICB therapy, and low interleukin-6 (IL-6) concentrations promoted their de novo differentiation. Mechanistically, CD5 expression by DCs was required to generate optimally protective CD5hi T helper and CD8+ T cells; further, deletion of CD5 from T cells dampened tumor elimination in response to ICB therapy in vivo. Thus, CD5+ DCs are an essential component of optimal ICB therapy.


Assuntos
Antígenos CD5 , Linfócitos T CD8-Positivos , Células Dendríticas , Inibidores de Checkpoint Imunológico , Imunoterapia , Melanoma , Linfócitos T Auxiliares-Indutores , Humanos , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular , Células Dendríticas/imunologia , Melanoma/tratamento farmacológico , Antígenos CD5/metabolismo , Inibidores de Checkpoint Imunológico/uso terapêutico , Linfócitos T Auxiliares-Indutores/imunologia
15.
Eur Arch Psychiatry Clin Neurosci ; 273(5): 1061-1072, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36738332

RESUMO

Childhood trauma (CT) has been linked to increased risk for psychosis. Moreover, CT has been linked to psychosis phenotypes such as impaired cognitive and sensory functions involved in the detection of novel sensory stimuli. Our objective was to investigate if CT was associated with changes in hippocampal and superior temporal gyrus functional activation and connectivity during a novelty detection task. Fifty-eight young adults were assigned to High-CT (n = 28) and Low-CT (n = 24) groups based on their scores on the childhood trauma questionnaire (CTQ) and underwent functional Magnetic Resonance Imaging during an auditory oddball task (AOT). Relative to the Low CT group, High CT participants showed reduced functional activation in the left hippocampus during the unpredictable tone condition of the AOT. Furthermore, in the High CT group, psychophysiological interaction analysis revealed hypoconnectivity between the hippocampus and temporal and medial regions. The present study indicates both altered hippocampal activation and hippocampal-temporal-prefrontal connectivity during novelty detection in individuals that experienced CT, similarly to that reported in psychosis risk populations. Early stressful experiences and environments may alter hippocampal function during salient events, mediating the relationship between childhood trauma and psychosis risk.


Assuntos
Experiências Adversas da Infância , Transtornos Psicóticos , Humanos , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/patologia , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Imageamento por Ressonância Magnética/métodos , Lobo Temporal
16.
Cogn Emot ; 37(2): 220-237, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36583855

RESUMO

Attentional control theory (ACT) was proposed to account for trait anxiety's effects on cognitive performance. According to ACT, impaired processing efficiency in high anxiety is mediated through inefficient executive processes that are needed for effective attentional control. Here we review the central assumptions and predictions of ACT within the context of more recent empirical evidence from neuroimaging studies. We then attempt to provide an account of ACT within a framework of the relevant cognitive processes and their associated neural mechanisms and networks, particularly the fronto-parietal, cingular-opercula, and default mode networks. Future research directions, including whether a neuroscience-informed model of ACT can provide a platform for novel neurocognitive intervention for anxiety, are also discussed.


Assuntos
Mapeamento Encefálico , Imageamento por Ressonância Magnética , Humanos , Mapeamento Encefálico/métodos , Ansiedade , Transtornos de Ansiedade , Lobo Parietal , Encéfalo , Vias Neurais
17.
Schizophr Bull ; 49(2): 339-349, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36516396

RESUMO

BACKGROUND AND HYPOTHESIS: Around 20% of people at clinical high risk (CHR) for psychosis later develop a psychotic disorder, but it is difficult to predict who this will be. We assessed the incidence of hearing speech (termed speech illusions [SIs]) in noise in CHR participants and examined whether this was associated with adverse clinical outcomes. STUDY DESIGN: At baseline, 344 CHR participants and 67 healthy controls were presented with a computerized white noise task and asked whether they heard speech, and whether speech was neutral, affective, or whether they were uncertain about its valence. After 2 years, we assessed whether participants transitioned to psychosis, or remitted from the CHR state, and their functioning. STUDY RESULTS: CHR participants had a lower sensitivity to the task. Logistic regression revealed that a bias towards hearing targets in stimuli was associated with remission status (OR = 0.21, P = 042). Conversely, hearing SIs with uncertain valence at baseline was associated with reduced likelihood of remission (OR = 7.72. P = .007). When we assessed only participants who did not take antipsychotic medication at baseline, the association between hearing SIs with uncertain valence at baseline and remission likelihood remained (OR = 7.61, P = .043) and this variable was additionally associated with a greater likelihood of transition to psychosis (OR = 5.34, P = .029). CONCLUSIONS: In CHR individuals, a tendency to hear speech in noise, and uncertainty about the affective valence of this speech, is associated with adverse outcomes. This task could be used in a battery of cognitive markers to stratify CHR participants according to subsequent outcomes.


Assuntos
Antipsicóticos , Ilusões , Transtornos Psicóticos , Humanos , Fala , Transtornos Psicóticos/epidemiologia , Transtornos Psicóticos/psicologia , Incidência
18.
Cognit Ther Res ; 47(1): 1-19, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36284796

RESUMO

Background: The COVID-19 pandemic has resulted in many individuals experiencing increased symptoms of anxiety. We predict that this increase may be underpinned by pandemic-related worry (PRW), characterised by repetitive negative thinking about pandemic-specific outcomes; and that this relationship is mediated through reduced attentional capacity required to regulate negative affect. Methods: We developed a novel scale to measure the contents of PRW in an initial sample of 255 participants, and explored its relationship with cognitive functioning and negative affect in a sample of 382 UK-based university students, whilst controlling for recalled pre-pandemic trait anxiety. Results: A five-factor model of PRW was identified, with factors reflecting worry about decline in quality of life (QoL) and probability of infection correlating with attention and memory-related errors. Importantly, attention-related errors partially mediated the positive relationship between PRW and negative affect, even when controlling for pre-pandemic trait anxiety. Conclusion: PRW's relationship with negative affect was partially mediated through attentional function, consistent with models of anxiety and attentional control. In UK-based students PRW may be predominantly focused on the decline in QoL; therefore, interventions targeting worry about the decline in QoL caused by COVID-19 are especially important in this population in the wake of the pandemic. Supplementary Information: The online version contains supplementary material available at 10.1007/s10608-022-10336-7.

20.
J Assoc Res Otolaryngol ; 23(6): 751-758, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36280641

RESUMO

Children with a history of temporary conductive hearing loss (CHL) during early development may show long-term impairments in auditory processes that persist after restoration of normal audiometric hearing thresholds. Tones in noise provide a simplified paradigm for studying hearing in noise. Prior research has shown that adults with sensorineural hearing loss may alter their listening strategy to use single-channel energy cues for tone-in-noise (TIN) detection rather than rove-resistant envelope or spectral profile cues. Our objective was to determine the effect of early CHL on TIN detection in healthy children compared to controls. Children ages 4-7 years, with and without a history of CHL due to otitis media with effusion (OME) before age 3 years, participated in a two-alternative forced choice TIN detection task. Audiometric thresholds were normal at the time of testing. Thresholds for detection of a 1000 Hz tone were measured in fixed-level noise and in roving-level noise that made single-channel energy cues unreliable. Participants included 23 controls and 23 with a history of OME-related CHL. TIN thresholds decreased with increasing age across participants. Children in both groups showed similar TIN sensitivity and little or no threshold elevation in the roving-level condition compared to fixed-level tracks, consistent with use of rove-resistant cues. In contrast to older listeners with sensorineural hearing loss, there was no detectable change in TIN sensitivity with roving level for children with a history of OME-related CHL.


Assuntos
Perda Auditiva Neurossensorial , Otite Média com Derrame , Adulto , Criança , Pré-Escolar , Humanos , Audiometria de Tons Puros , Limiar Auditivo , Audição , Perda Auditiva Condutiva/diagnóstico , Otite Média com Derrame/diagnóstico
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