Clementz B A, Geyer M A, Braff D L
Department of Psychology, University of California, La Jolla, San Diego 92093-0109, USA.
Schizophr Res. 1998 Feb 27;30(1):71-80. doi: 10.1016/s0920-9964(97)00122-9.
Normally, when two brief, non-startling auditory stimuli are presented 500 ms apart, with long (e.g., 10 s) interpair intervals, the positive potential occurring approx. 50 ms after the first stimulus (P50) is relatively large, and the P50 to the second stimulus is smaller. In schizophrenia patients, however, the P50 to the second stimulus is larger than normal. In this study, 36 schizophrenia and 36 normal comparison subjects were tested in a two-click paradigm. Data were recorded from six electrode locations (F3, Fz, F4, C3, Cz, C4). The results support the hypothesis that schizophrenia patients have poor P50 suppression that is not an artifact of differential P50 wave morphology or differences in the number of usable trials between groups. In addition, the vertex location alone (Cz) was equal to, if not better than, any combination of sites for differentiating between groups. These results support the use of the Cz site alone in most investigations of P50 suppression deficits among schizophrenia spectrum patients. Further work investigating the neuropathological correlates of poor P50 suppression among schizophrenia patients by recording from multiple electrode locations, however, could be helpful.
通常情况下，当两个短暂、无惊吓作用的听觉刺激相隔500毫秒呈现，且配对间隔时间较长（例如10秒）时，在第一个刺激后约50毫秒出现的正电位（P50）相对较大，而对第二个刺激的P50则较小。然而，在精神分裂症患者中，对第二个刺激的P50比正常情况要大。在本研究中，36名精神分裂症患者和36名正常对照受试者接受了双点击范式测试。数据从六个电极位置（F3、Fz、F4、C3、Cz、C4）记录。结果支持了这样的假设，即精神分裂症患者的P50抑制功能较差，这并非是P50波形态差异或组间可用试验次数差异造成的假象。此外，仅顶点位置（Cz）在区分组间差异方面即便不比任何位点组合更好，至少也是相当的。这些结果支持在大多数对精神分裂症谱系患者P50抑制缺陷的研究中单独使用Cz位点。然而，通过从多个电极位置记录来进一步研究精神分裂症患者P50抑制功能差的神经病理学相关性可能会有所帮助。
