Faculdade de Psicologia, Universidade de Lisboa, Lisboa, Portugal.
Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Neuropsychologia. 2020 Sep;146:107531. doi: 10.1016/j.neuropsychologia.2020.107531. Epub 2020 Jun 14.
Auditory verbal hallucinations (AVH) are a cardinal symptom of psychosis but are also present in 6-13% of the general population. Alterations in sensory feedback processing are a likely cause of AVH, indicative of changes in the forward model. However, it is unknown whether such alterations are related to anomalies in forming an efference copy during action preparation, selective for voices, and similar along the psychosis continuum. By directly comparing psychotic and nonclinical voice hearers (NCVH), the current study specifies whether and how AVH proneness modulates both the efference copy (Readiness Potential) and sensory feedback processing for voices and tones (N1, P2) with event-related brain potentials (ERPs).
Controls with low AVH proneness (n = 15), NCVH (n = 16) and first-episode psychotic patients with AVH (n = 16) engaged in a button-press task with two types of stimuli: self-initiated and externally generated self-voices or tones during EEG recordings.
Groups differed in sensory feedback processing of expected and actual feedback: NCVH displayed an atypically enhanced N1 to self-initiated voices, while N1 suppression was reduced in psychotic patients. P2 suppression for voices and tones was strongest in NCVH, but absent for voices in patients. Motor activity preceding the button press was reduced in NCVH and patients, specifically for sensory feedback to self-voice in NCVH.
These findings suggest that selective changes in sensory feedback to voice are core to AVH. These changes already show in preparatory motor activity, potentially reflecting changes in forming an efference copy. The results provide partial support for continuum models of psychosis.
听觉言语幻觉（AVH）是精神病学的主要症状，但也存在于 6-13%的普通人群中。感觉反馈处理的改变可能是 AVH 的原因，表明前向模型发生了变化。然而，尚不清楚这种改变是否与在动作准备过程中形成针对声音的传出副本的异常有关，并且在精神病连续体中类似。通过直接比较精神病和非临床声音聆听者（NCVH），本研究具体说明了 AVH 倾向是否以及如何调节声音和音调的传出副本（准备电位）和感觉反馈处理（N1、P2）与事件相关脑电位（ERPs）。
低 AVH 倾向的对照组（n=15）、NCVH（n=16）和首次出现 AVH 的首发精神病患者（n=16）在 EEG 记录期间进行按钮按压任务，有两种类型的刺激：自我启动和外部生成的自我声音或音调。
组间在预期和实际反馈的感觉反馈处理上存在差异：NCVH 显示出自我启动声音的异常增强的 N1，而精神病患者的 N1 抑制减少。声音和音调的 P2 抑制在 NCVH 中最强，但在患者中则不存在。在 NCVH 和患者中，按钮按下之前的运动活动减少，特别是在 NCVH 中对自我声音的感觉反馈。
这些发现表明，对声音的感觉反馈的选择性改变是 AVH 的核心。这些变化已经出现在预备运动活动中，可能反映了传出副本形成的变化。结果为精神病的连续体模型提供了部分支持。
