Bolton Thomas A W, Wotruba Diana, Buechler Roman, Theodoridou Anastasia, Michels Lars, Kollias Spyros, Rössler Wulf, Heekeren Karsten, Van De Ville Dimitri
Institute of Bioengineering, École Polytechique Fédérale de Lausanne, Lausanne, Switzerland.
Department of Radiology and Medical Informatics, Université de Genève, Geneva, Switzerland.
Front Physiol. 2020 Feb 11;11:66. doi: 10.3389/fphys.2020.00066. eCollection 2020.
Emerging evidence has attributed altered network coordination between the default mode, central executive, and salience networks (DMN/CEN/SAL) to disturbances seen in schizophrenia, but little is known for at-risk psychosis stages. Moreover, pinpointing impairments in specific network-to-network interactions, although essential to resolve possibly distinct harbingers of conversion to clinically diagnosed schizophrenia, remains particularly challenging. We addressed this by a dynamic approach to functional connectivity, where right anterior insula brain interactions were examined through co-activation pattern (CAP) analysis. We utilized resting-state fMRI in 19 subjects suffering from subthreshold delusions and hallucinations (UHR), 28 at-risk for psychosis with basic symptoms describing only self-experienced subclinical disturbances (BS), and 29 healthy controls (CTR) matched for age, gender, handedness, and intelligence. We extracted the most recurring CAPs, compared their relative occurrence and average dwell time to probe their temporal expression, and quantified occurrence balance to assess the putative loss of competing relationships. Our findings substantiate the pivotal role of the right anterior insula in governing CEN-to-DMN transitions, which appear dysfunctional prior to the onset of psychosis, especially when first attenuated psychotic symptoms occur. In UHR subjects, it is longer active in concert with the DMN and there is a loss of competition between a SAL/DMN state, and a state with insula/CEN activation paralleled by DMN deactivation. These features suggest that abnormal network switching disrupts one's capacity to distinguish between the internal world and external environment, which is accompanied by inflexibility and an excessive awareness to internal processes reflected by prolonged expression of the right anterior insula-default mode co-activation pattern.
新出现的证据表明，精神分裂症中出现的紊乱与默认模式网络、中央执行网络和突显网络（DMN/CEN/SAL）之间的网络协调改变有关，但对于精神病风险阶段却知之甚少。此外，确定特定网络间相互作用中的损伤，虽然对于解决可能不同的向临床诊断精神分裂症转变的先兆至关重要，但仍然极具挑战性。我们通过一种动态功能连接方法来解决这个问题，其中通过共激活模式（CAP）分析来检查右前岛叶的脑内相互作用。我们对19名患有阈下妄想和幻觉的受试者（UHR）、28名有精神病风险且仅有自我体验的亚临床紊乱基本症状的受试者（BS）以及29名年龄、性别、利手和智力相匹配的健康对照者（CTR）进行了静息态功能磁共振成像研究。我们提取了最常见的CAP，比较它们的相对出现频率和平均停留时间以探究其时间表达，并量化出现平衡以评估竞争关系的假定丧失。我们的研究结果证实了右前岛叶在控制CEN向DMN转变中的关键作用，这种转变在精神病发作前似乎就已功能失调，尤其是在首次出现轻度精神病症状时。在UHR受试者中，它与DMN协同活动的时间更长，并且在SAL/DMN状态和岛叶/CEN激活且DMN失活的状态之间存在竞争丧失。这些特征表明，异常的网络切换会破坏个体区分内部世界和外部环境的能力，这伴随着僵化以及对内部过程的过度意识，这通过右前岛叶 - 默认模式共激活模式的延长表达得以体现。
