Faux S F, Shenton M E, McCarley R W, Nestor P G, Marcy B, Ludwig A
Harvard Medical School, Department of Psychiatry, Brockton VAMC, MA 02401.
Electroencephalogr Clin Neurophysiol. 1990 May;75(5):378-91. doi: 10.1016/0013-4694(90)90083-v.
Previous studies of the auditory P300 event-related potential (ERP) from our laboratory have reported a left- greater than right-sided attenuation in medicated chronic schizophrenics compared with normal controls. A possible confound in these studies has been the use of the linked-ear reference (LER), which has been criticized on the grounds that it might either induce or suppress topographic asymmetries. To test the effects of LER on P300 asymmetries in schizophrenia, we recorded ERPs with both LER and a nose reference (NR) in a group of 20 chronic medicated schizophrenics and in group of 20 age-matched normal controls. We here report: (1) confirmation of our previous P300 findings of left temporal scalp region deficit using both LER and NR with a 28-electrode montage; this feature was prominent in the wave form associated with the target stimulus, without the use of the wave form subtractions of our previous studies; (2) no statistically significant topographic differences between the LER and NR for either the schizophrenic or normal subjects; and (3) better performance of the LER in differentiating schizophrenics versus normal controls, due to lower wave form variability. We conclude that the LER is preferable for studies using subject groups and methodology similar to the present study.
我们实验室之前关于听觉P300事件相关电位（ERP）的研究报告称，与正常对照组相比，药物治疗的慢性精神分裂症患者左侧的衰减大于右侧。这些研究中一个可能的混淆因素是使用了双耳链接参考（LER），有人批评它可能会诱发或抑制地形不对称。为了测试LER对精神分裂症患者P300不对称性的影响，我们在一组20名接受药物治疗的慢性精神分裂症患者和一组20名年龄匹配的正常对照组中，分别使用LER和鼻参考（NR）记录了ERP。我们在此报告：（1）使用28电极蒙太奇，通过LER和NR均证实了我们之前关于左颞头皮区域缺陷的P300研究结果；这一特征在与目标刺激相关的波形中很突出，无需像我们之前研究那样进行波形减法；（2）对于精神分裂症患者或正常受试者，LER和NR之间在地形上没有统计学上的显著差异；（3）由于波形变异性较低，LER在区分精神分裂症患者与正常对照组方面表现更好。我们得出结论，对于使用与本研究类似的受试者群体和方法的研究，LER更可取。
