Biomarkers of auditory processing in schizophrenia: do they reflect symptom severity? An investigation in schizotypy

精神分裂症患者听觉处理的生物标记物异常，提示它们有潜在的 在精神病发作之前识别正在经历精神分裂症样症状的个人。 然而，为了使这些生物标记物有效，它们需要反映症状的严重程度。有一些 一般人群中表现出精神分裂症样特征但没有精神病的个体， 通常被称为分裂型。大多数一般人口被认为是沿着以下范围下降的 分裂型行为，有些症状较重，被称为“高度分裂型”。 这个项目的目的是测试与精神分裂症相关的听觉生物标记物是否也存在于 高度分裂型的个体，以及不同的生物标记物如何相互关联。如果听觉系统 生物标记物在高度分裂型中受到影响，那么这将支持它们用于识别那些处于- 罹患精神分裂症的风险。如果不是，那么这表明精神分裂症患者绝对是 在听觉处理方面与普通人群不同，并表明在 精神病的发作。在目前的研究中，我们专注于早期感觉记忆(错配)的生物标志物 负性；MMN)和后来的听觉工作记忆(WM)的脑电和行为 心理物理学。我们还将探索感觉记忆和工作记忆如何相互影响，作为一种潜在的机制 在分裂类型中的听觉处理。该项目旨在向本科生介绍临床研究人员。 研究。他们将学习如何收集电生理数据、分析技术，并将参与 传播结果。 该项目将分为三个目标。AIM 1将测量脑电中的MMN进行早期调查 对听觉异常的感觉记忆--音高不同的单音。AIM 2将调查WM性能 在3-back任务中，使用行为和脑电测量(如刺激编码期间的N1)。我们会调查的 MMN和WM相互独立，因此目标1的结果不会影响目标2。对于目标1和目标2，我们 假设与低分裂类型相比，高分裂类型的人的MMN和WM表现都会受到损害。 然后，目标3将研究这两种听觉处理方法之间的关系。我们假设 受损的MMN将预测较差的WM性能(使用回归分析进行检验)，并且这种关系 在高分裂类型下会比低分裂类型更强。这将表明一个潜在的机制可以作为目标 治疗：改善早期听觉记忆，影响后期听觉相关认知。如果没有显著的 感觉记忆和工作记忆之间的关系，那么这将表明第三个影响听觉的变量 正在处理。这两个结果都将有助于建立分裂学中的听觉处理模型。 本科生研究人员将加深对生物标记物在精神病学中的作用的理解，并 如何利用基础科学来研究精神分裂症的发病机制。

Biomarkers of auditory processing are abnormal in schizophrenia, suggesting their potential for identifying individuals who are experiencing schizophrenia-like symptoms before the onset of psychosis. However, for these biomarkers to be effective, they would need to reflect symptom severity. There are some individuals in the general population who exhibit schizophrenia-like traits but do not experience psychosis, commonly known as schizotypy. The majority of the general population is believed to fall along a spectrum of schizotypic behaviors, with some being more symptomatic and who are referred to as having `high schizotypy'. The aim of this project is to test whether auditory biomarkers associated with schizophrenia are also present in individuals with high schizotypy, and how the different biomarkers relate to one another. If the auditory biomarkers are impacted in high schizotypy, then this would support their use for identifying those who are at- risk of developing schizophrenia. If not, then this suggests that individuals with schizophrenia are categorically different in their auditory processing to the general population, and indicates substantial brain-wide changes at the onset of psychosis. In the current study, we focus on biomarkers of early sensory memory (mismatch negativity; MMN) and later auditory working memory (WM) using electroencephalography (EEG) and behavioral psychophysics. We will also explore how sensory memory and WM impact one other, as a potential mechanism of auditory processing in schizotypy. This project is designed to introduce undergraduate researchers to clinical research. They will learn how to collect electrophysiological data, analysis techniques, and will be involved in disseminating the results. The project will be divided into three Aims. Aim 1 will measure MMN in the EEG to investigate early sensory memory to auditory deviants – single tones that differ in pitch. Aim 2 will investigate WM performance in a 3-back task using behavioral and EEG measures (such as N1 during stimulus encoding). We will investigate MMN and WM independently so that the results from Aim 1 do not impact Aim 2. For Aims 1 and 2, we hypothesize that both MMN and WM performance will be impaired in those with high compared to low schizotypy. Aim 3 will then examine the relationship between the two measures of auditory processing. We hypothesize that impaired MMN will predict poorer WM performance (examined using regression analyses), and this relationship will be stronger in high compared to low schizotypy. This will indicate a potential mechanism to target for treatment: improve early auditory memory to impact later auditory-related cognition. If there is no significant relationship between sensory memory and WM, then this will indicate a third variable that impacts auditory processing. Either result will contribute to a model of auditory processing in schizotypy. Undergraduate researchers will develop an understanding of the utility of biomarkers in psychiatry, and how basic science can be used to investigate the mechanisms underlying schizophrenia.