University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251, Hamburg, Germany.
Harvard Medical School, 25 Shattuck St, Boston, MA, 02115, USA; McLean Hospital, 115 Mill St Belmont, MA, 02478, USA.
J Psychiatr Res. 2021 Dec;144:37-44. doi: 10.1016/j.jpsychires.2021.09.034. Epub 2021 Sep 23.
Decreased mismatch negativity (MMN) is a proposed biomarker for psychotic disorders. However, the magnitude of the effect appears to be attenuated in first-episode populations. Furthermore, how mismatch negativity amplitudes are related to brain connectivity in this population is unclear. In this study, we used high-density EEG to record duration-deviant MMN from 22 patients with first-episode psychosis (FEP) and 23 age-matched controls (HC). Consistent with past work, we found decreased MMN amplitude in FEP over a large area of the frontal scalp. We also found decreased latency over the occipital scalp. MMN amplitude was negatively correlated with antipsychotic dose. We used Granger causality to investigate directional connectivity between frontal, midline, left, and right scalp during MMN and found reduced connectivity in FEP compared to HC and following deviant stimuli compared to standard stimuli. FEP participants with smaller decreases in connectivity from standard to deviant stimuli had worse disorganization symptoms. On the other hand, connectivity from the front of the scalp following deviant stimuli was relatively preserved in FEP compared to controls. Our results suggest that a relative imbalance of bottom-up and top-down perceptual processing is present in the early stages of psychotic disorders.
错配负波（MMN）减少被认为是精神障碍的生物标志物。然而，首发患者群体中这种效应的幅度似乎减弱了。此外，在该人群中，错配负波幅度与大脑连通性之间的关系尚不清楚。在这项研究中，我们使用高密度 EEG 从 22 名首发精神病患者（FEP）和 23 名年龄匹配的对照组（HC）中记录了时长偏差 MMN。与过去的研究一致，我们发现 FEP 患者在前额头皮的大面积区域出现 MMN 振幅降低。我们还发现枕叶头皮上的潜伏期降低。MMN 幅度与抗精神病药物剂量呈负相关。我们使用格兰杰因果关系来研究 MMN 期间前额、中线、左侧和右侧头皮之间的定向连通性，发现与 HC 相比，FEP 的连通性降低，与标准刺激相比，偏离刺激后的连通性降低。与标准刺激相比，偏离刺激后，从标准到偏离刺激的连通性减少幅度较小的 FEP 患者的组织障碍症状更严重。另一方面，与对照组相比，FEP 中偏离刺激后的头皮前部的连通性相对保留。我们的结果表明，在精神病障碍的早期阶段，存在自上而下和自下而上的感知处理的相对不平衡。
