Mental Illness Research, Education and Clinical Center, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America.
Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California, United States of America.
PLoS One. 2019 Aug 20;14(8):e0221409. doi: 10.1371/journal.pone.0221409. eCollection 2019.
People with schizophrenia (SZ) or bipolar disorder (BD) experience dysfunction in visual processing. Dysfunctional neural tuning, in which neurons and neuronal populations are selectively activated by specific features of visual stimuli, may contribute to these deficits. Few studies have examined this possibility and there are inconsistent findings of tuning deficits in the literature. We utilized an event-related potential (ERP) paradigm to examine neural adaptation for visual objects, a measure of neural tuning whereby neurons respond less strongly to the repeated presentation of the same stimulus. Seventy-seven SZ, 53 BD, and 49 healthy comparison participants (HC) were examined. In three separate conditions, pictures of objects were presented repeatedly: the same object (SS), different objects from the same category (e.g., two different vases; SD), or different objects from different categories (e.g., a barrel and a clock, DD). Mass-univariate cluster-based permutation analyses identified electrodes and time-windows in which there were significant differences between the SS vs. DD and the SD vs. DD conditions. Mean ERP amplitudes were extracted from these clusters and analyzed for group differences. Results revealed a significant condition difference over parieto-occipital electrodes for the SS-DD comparison between 109-164 ms and for the SD-DD comparison between 78-203 ms, with larger amplitudes in the DD compared to either SS or SD condition. However, there were no significant differences in the pattern of results between groups. Thus, while we found neural adaptation effects using this ERP paradigm, we did not find evidence of group differences. Our results suggest that people with SZ or BD may not exhibit deficits in neural tuning for processing of visual objects using this EEG task with rapidly presented stimuli. However, the results are inconsistent with other studies using different methodologies (e.g., fMRI, behavioral tasks) that have found tuning deficits in people with schizophrenia.
精神分裂症（SZ）或双相情感障碍（BD）患者的视觉处理存在功能障碍。神经调谐功能障碍，即神经元和神经元群体被视觉刺激的特定特征选择性激活，可能导致这些缺陷。很少有研究探讨这种可能性，并且文献中存在调谐缺陷的不一致发现。我们利用事件相关电位（ERP）范式来研究视觉对象的神经适应，这是一种衡量神经调谐的方法，即神经元对相同刺激的重复呈现反应较弱。研究了 77 名 SZ、53 名 BD 和 49 名健康对照组（HC）参与者。在三个单独的条件下，重复呈现物体的图片：相同的物体（SS）、来自同一类别的不同物体（例如，两个不同的花瓶；SD）或来自不同类别的不同物体（例如，一个桶和一个钟，DD）。基于体素的集群多元聚类置换分析确定了在 SS 与 DD 和 SD 与 DD 条件之间存在显著差异的电极和时间窗口。从这些聚类中提取平均 ERP 幅度，并分析组间差异。结果显示，在 SS-DD 比较中，109-164ms 时，在 SD-DD 比较中，78-203ms 时，顶枕部电极存在显著的条件差异，DD 条件下的振幅大于 SS 或 SD 条件。然而，组间的结果模式没有显著差异。因此，虽然我们使用这个 ERP 范式发现了神经适应效应，但我们没有发现组间差异的证据。我们的研究结果表明，SZ 或 BD 患者在使用这种具有快速呈现刺激的 EEG 任务处理视觉对象时，可能不会表现出神经调谐缺陷。然而，这些结果与使用不同方法（例如 fMRI、行为任务）发现精神分裂症患者存在调谐缺陷的其他研究不一致。
