Clinical Research Unit, Brain and Mind Research Institute, The University of Sydney, Sydney, Australia.
Prog Neuropsychopharmacol Biol Psychiatry. 2010 Aug 16;34(6):822-9. doi: 10.1016/j.pnpbp.2010.03.019. Epub 2010 Mar 17.
Mismatch negativity (MMN) is a neurophysiological indicator of the brain's ability to extract relevant information from an irrelevant background. The P3a orienting response often accompanies MMN in deviance detection paradigms. Both MMN and P3a have been described as reliable biomarkers of schizophrenia. MMN/P3a impairments are associated with deficits in verbal memory and attentional switching, reflecting dysfunctions in the temporal and frontal systems, respectively. It remains unresolved whether MMN/P3a are robust biomarkers of psychosis in first-episode patients. Thirty-four young people (18 to 30years) were assessed in this study; 17 first-episode psychosis (FEP) patients were compared to 17 healthy controls. To elicit MMN/P3a, a two-tone passive auditory oddball paradigm with 8% duration deviants was used; event-related potentials were recorded at frontal, central and temporal (mastoid) sites. Neuropsychological assessments included processing speed, attentional switching, simple attention, and verbal learning and memory. Social functioning and quality of life measures were also obtained. The FEP group showed significantly reduced MMN amplitudes compared to controls. The FEP group also showed significantly reduced P3a amplitudes at frontal and central sites compared with controls. As expected, the FEP group also showed significant deficits in attention and verbal learning/memory. Correlational analyses found strong associations between fronto-central MMN/P3a peak amplitude and cognitive/psychosocial functioning. This study provides evidence of early neurobiological markers in young people with FEP. These findings suggest that MMN/P3a impairments are present at early stages of psychosis and that fundamental pre-attentive/deviance detection deficits may mark the beginning of progressive underlying changes with illness onset. Such deficits in FEP appear to have important links with higher-order cognitive and psychosocial functioning.
失匹配负波（MMN）是大脑从无关背景中提取相关信息的能力的神经生理指标。在偏离检测范式中，P3a 朝向反应通常伴随着 MMN。MMN 和 P3a 都被描述为精神分裂症的可靠生物标志物。MMN/P3a 损伤与言语记忆和注意力转换缺陷有关，分别反映了颞叶和额叶系统的功能障碍。MMN/P3a 是否是首发精神分裂症患者的可靠精神病生物标志物仍未解决。本研究评估了 34 名年轻人（18 至 30 岁）；17 名首发精神分裂症（FEP）患者与 17 名健康对照进行比较。为了引出 MMN/P3a，使用了一个具有 8%持续时间偏差的双音被动听觉奇偶校验范式；在额、中、颞（乳突）部位记录事件相关电位。神经心理学评估包括处理速度、注意力转换、简单注意力、言语学习和记忆。还获得了社会功能和生活质量的测量结果。与对照组相比，FEP 组的 MMN 振幅明显降低。与对照组相比，FEP 组在前额和中央部位的 P3a 振幅也明显降低。正如预期的那样，FEP 组在注意力和言语学习/记忆方面也存在明显缺陷。相关分析发现额中央 MMN/P3a 峰振幅与认知/社会心理功能之间存在很强的关联。这项研究为 FEP 年轻人提供了早期神经生物学标志物的证据。这些发现表明，MMN/P3a 损伤存在于精神病的早期阶段，基本的前注意/偏离检测缺陷可能标志着随着疾病发作潜在变化的开始。FEP 中的这些缺陷似乎与更高阶的认知和社会心理功能有重要联系。
