In visual backward masking (VBM), a target is followed by a mask that decreases target discriminability. Schizophrenia patients (SZ) show strong and reproducible masking impairments, which are associated with reduced EEG amplitudes. Patients with bipolar disorder (BP) show masking deficits, too. Here, we investigated the neural EEG correlates of VBM in BP. 122 SZ, 94 unaffected controls, and 38 BP joined a standard VBM experiment. 123 SZ, 94 unaffected controls and 16 BP joined a corresponding EEG experiment, analyzed in terms of global field power. As in previous studies, SZ and BP show strong masking deficits. Importantly and similarly to SZ, BP show decreased global field power amplitudes at approximately 200 ms after the target onset, compared to controls. These results suggest that VBM deficits are not specific for schizophrenia but for a broader range of functional psychoses. Potentially, both SZ and BP show deficient target enhancement.

中文翻译：

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双相障碍患者视觉后向掩蔽的电生理相关性

在视觉后向掩蔽 (VBM) 中，目标后面跟着一个掩码，降低了目标的可辨别性。精神分裂症患者 (SZ) 表现出强烈且可重复的掩蔽障碍，这与脑电图振幅降低有关。双相情感障碍 (BP) 患者也表现出掩蔽缺陷。在这里，我们研究了 BP 中 VBM 的神经 EEG 相关性。122 个 SZ、94 个未受影响的对照和 38 个 BP 加入了标准的 VBM 实验。123 个 SZ、94 个未受影响的对照和 16 个 BP 加入了相应的 EEG 实验，根据全局场功率进行分析。与之前的研究一样，SZ 和 BP 表现出强烈的掩蔽缺陷。重要的是，与 SZ 类似，与对照相比，BP 在目标开始后大约 200 毫秒显示出降低的全局场功率振幅。这些结果表明，VBM 缺陷不是精神分裂症所特有的，而是更广泛的功能性精神病。潜在地，SZ 和 BP 都显示出目标增强不足。