Ward P B, Hoffer L D, Liebert B J, Catts S V, O'Donnell M, Adler L E
Department of Psychiatry, Prince of Wales Hospital, Sydney, Australia.
Psychiatry Res. 1996 Sep 27;64(2):121-35. doi: 10.1016/0165-1781(96)02876-4.
Schizophrenic patients reportedly have a deficit in the control of sensitivity to auditory stimuli as shown by the P50 auditory evoked potential wave in a conditioning-testing paradigm that measures suppression of response to a repeated stimulus. Although this finding has been replicated by several US laboratories, one European group has not found differences between schizophrenic patients and normal control subjects. In the present study, investigators in the Schizophrenia Research Center at the Prince of Wales Hospital in Sydney, Australia, selected 22 normal control subjects, 11 acutely ill schizophrenic inpatients, and 11 clinically stable schizophrenic outpatients. Both schizophrenic groups were treated with similar doses of classical neuroleptic medications. Evoked potentials were recorded by an investigator from the US laboratory that initially reported the difference; five averages, each the response to 32 stimulus pairs, were recorded from each subject. The normal control subjects demonstrated significantly more suppression of the P50 response to the repeated stimuli than the schizophrenic groups, as previously reported. There were no significant changes in the suppression measure over the five trials. The suppression of the P50 wave by schizophrenic outpatients was somewhat greater than that by schizophrenic inpatients, but both schizophrenic groups had decreased suppression, compared with the normal subjects. The mean P50 suppression for five averages was successfully used in a logistic regression to classify subjects as normal or schizophrenic. This method was more accurate than attempts to classify subjects with only one average. The mean amplitude of the initial conditioning response did not differ between groups. Schizophrenic patients had slightly shorter mean latencies. There was no direct relationship of P50 suppression to measures of clinical psychopathology.
据报道，精神分裂症患者在控制对听觉刺激的敏感度方面存在缺陷，这在一种条件测试范式中通过P50听觉诱发电位波得以体现，该范式用于测量对重复刺激的反应抑制。尽管这一发现已被多个美国实验室重复验证，但一个欧洲研究小组并未发现精神分裂症患者与正常对照受试者之间存在差异。在本研究中，澳大利亚悉尼威尔士亲王医院精神分裂症研究中心的研究人员选取了22名正常对照受试者、11名急性发病的精神分裂症住院患者以及11名临床症状稳定的精神分裂症门诊患者。两个精神分裂症患者组均接受了相似剂量的经典抗精神病药物治疗。诱发电位由最初报道该差异的美国实验室的一名研究人员记录；从每位受试者记录了五个平均值，每个平均值是对32对刺激的反应。与之前报道的一样，正常对照受试者对重复刺激的P50反应抑制明显多于精神分裂症患者组。在五次试验中，抑制测量结果没有显著变化。精神分裂症门诊患者对P50波的抑制略大于住院患者，但与正常受试者相比，两个精神分裂症患者组的抑制均有所降低。五个平均值的P50平均抑制成功用于逻辑回归，以将受试者分类为正常或精神分裂症患者。这种方法比仅用一个平均值对受试者进行分类更为准确。初始条件反应的平均振幅在各组之间没有差异。精神分裂症患者的平均潜伏期略短。P50抑制与临床精神病理学测量指标之间没有直接关系。
