Testing a Bayesian model of auditory verbal hallucinations in the adolescent brain

测试青少年大脑中幻听的贝叶斯模型

• 批准号: 2775240
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2775240
• 关键词: Testing; Bayesian; model; auditory; verbal

Auditory verbal hallucinations (AVH) are a characteristic symptom of psychotic states such as schizophrenia. Adolescents are particular vulnerable to developing AVH and schizophrenia (Dalsgaard et al., 2020). It is imperative to characterise and model the developmental mechanisms of psychosis and to develop effective methods for early detection and diagnosis to optimize interventions. Little is certain about how the brain produces AVH. Some theories propose that AVH result from a failure to monitor one's own inner speech, verbal thoughts or memories so that they are perceived to be foreign or external (Frith, 2014). Others claim that AVH are intrusive memories (often from childhood traumatic events) that the brain fails to suppress (Waters et al., 2006). Because each of these models localises the pathology of AVH to one symptom dimension or cognitive mechanism, none can explain the full complexity of AVH alone. 'Bayesian inferencing' has become increasingly influential as it has the potential to unify multiple mechanisms of AVH under a generalised theoretical framework. The brain may use different mechanisms to compute the probability of a perception given prior experience and the current sensations. So whether speech is heard ultimately depends on the weight the brain attaches to previous experience (the priors) and to what is currently being heard. AVH may occur in the absence of a stimulus when the brain has a very strong and unchanging prior expectation (Corlett et al., 2019). The current project aims to test the Bayesian model of AVH to characterise and model the developmental mechanisms of AVH in adolescents. We will recruit people aged 15-25yo and: (1) prove the concept of a modelling approach by modelling experimentally manipulated prior beliefs (of hearing a speech) and sensory evidence (of whether the speech is present) in a series of signal detection tasks (Brookwell et al., 2013); (2) test if Bayesian modelling can separate healthy vs. at-risk and clinical groups more reliably than tasks measuring corollary discharge, source monitoring or memory inhibition; (3) localise the changes of prior beliefs to electrophysiological signatures in the brain using EEG (Yao et al., 2021), to identify potential biomarkers for non-invasive brain stimulation treatments. The PhD will benefit from interdisciplinary expertise in cognitive neuroscience and clinical psychology and receive comprehensive training in quantitative skills in Bayesian modelling, statistical analysis and EEG data processing, as well as in clinical assessment of psychotic symptoms and research governance

听觉言语幻觉（AVH）是精神分裂症等精神病状态的特征性症状。青少年特别容易发展成AVH和精神分裂症（Dalsgaard等人，2020年）。因此，有必要对精神病的发展机制进行建模和建模，并开发早期发现和诊断的有效方法，以优化干预措施。关于大脑是如何产生AVH的，目前还不确定。一些理论认为AVH是由于未能监控自己的内心言语，言语思想或记忆，因此它们被认为是外来的或外部的（Frith，2014）。其他人声称AVH是大脑无法抑制的侵入性记忆（通常来自童年创伤事件）（沃茨等人，2006年）。由于这些模型都将AVH的病理局限于一个症状维度或认知机制，因此没有一个模型可以单独解释AVH的全部复杂性。“贝叶斯推理”的影响力越来越大，因为它有可能将AVH的多种机制统一在一个通用的理论框架下。大脑可以使用不同的机制来计算给定先前经验和当前感觉的感知概率。因此，是否能听到言语最终取决于大脑对先前经验（先验）和当前听到的内容的重视程度。AVH可能在没有刺激的情况下发生，此时大脑具有非常强且不变的先前期望（Corlett等人，2019年）。目前的项目旨在测试AVH的贝叶斯模型，以预测和模拟青少年AVH的发展机制。我们将招募15- 25岁的人，并：（1）通过在一系列信号检测任务中对实验操纵的先前信念（听到演讲）和感官证据（演讲是否存在）进行建模来证明建模方法的概念（Brookwell等人，2013年）;（2）测试贝叶斯模型是否可以比测量必然放电、源监测或记忆抑制的任务更可靠地区分健康组、高危组和临床组;（3）使用脑电将先前信念的变化定位到大脑中的电生理特征（Yao等人，2021），以确定用于非侵入性脑刺激治疗的潜在生物标志物。博士将受益于认知神经科学和临床心理学的跨学科专业知识，并在贝叶斯建模，统计分析和EEG数据处理以及精神病症状和研究治理的临床评估方面接受定量技能的全面培训。