Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Institute for Systems and Robotics - Lisbon (LARSyS) and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.
Schizophr Bull. 2020 Jul 8;46(4):1009-1018. doi: 10.1093/schbul/sbz133.
Visual backward masking (VBM) deficits are candidate endophenotypes of schizophrenia indexing genetic liability of the disorder. In VBM, a target is followed by a mask that deteriorates target perception. Schizophrenia patients and, to a lesser extent, their unaffected relatives show strong and reproducible VBM deficits. In patients, VBM deficits are associated with strongly decreased amplitudes in the evoked-related potentials (ERPs). Here, to unveil the neural mechanisms of VBM in schizophrenia, circumventing illness-specific confounds, we investigated the electroencephalogram correlates of VBM in unaffected siblings of schizophrenia patients. We tested 110 schizophrenia patients, 60 siblings, and 83 healthy controls. As in previous studies, patients showed strong behavioral deficits and decreased ERP amplitudes compared to controls. Surprisingly, the ERP amplitudes of siblings were even higher than the ones of controls, while their performances were similar. ERP amplitudes in siblings were found to correlate with performance. These results suggest that VBM is deteriorated in patients and siblings. However, siblings, unlike patients, can partially compensate for the deficits by over-activating a network of brain regions.
视觉后向掩蔽 (VBM) 缺陷是精神分裂症的候选内表型，反映了该疾病的遗传易感性。在 VBM 中，目标后面跟着一个掩蔽，会降低目标的感知。精神分裂症患者，以及在较小程度上，他们未受影响的亲属表现出强烈且可重复的 VBM 缺陷。在患者中，VBM 缺陷与诱发相关电位 (ERP) 的幅度明显降低有关。在这里，为了揭示精神分裂症中 VBM 的神经机制，我们避免了与疾病特异性相关的混杂因素，研究了精神分裂症患者未受影响的兄弟姐妹的 VBM 与脑电图的相关性。我们测试了 110 名精神分裂症患者、60 名兄弟姐妹和 83 名健康对照者。与之前的研究一样，患者与对照组相比，表现出明显的行为缺陷和 ERP 幅度降低。令人惊讶的是，兄弟姐妹的 ERP 幅度甚至高于对照组，而他们的表现相似。发现兄弟姐妹的 ERP 幅度与表现相关。这些结果表明，VBM 在患者和兄弟姐妹中都受到了损害。然而，与患者不同，兄弟姐妹可以通过过度激活大脑区域网络来部分补偿缺陷。
