Patterson J V, Jin Y, Gierczak M, Hetrick W P, Potkin S, Bunney W E, Sandman C A
Department of Neurology, University of California, Irvine, USA.
Arch Gen Psychiatry. 2000 Jan;57(1):57-64. doi: 10.1001/archpsyc.57.1.57.
Deficits in attention and cognition are common in schizophrenia. Using an auditory dual-click paradigm, a number of studies have found that, compared with normal controls, patients with schizophrenia show impaired inhibition, or gating, of repeated stimulation as measured by the average P50 evoked response to the second click. Since responses to many trials are collected to study the average response, fluctuations in the timing of the P50 response from trial to trial may influence the differences observed. We present a computerized, objective procedure that evaluates temporal variability in brain responses of patients with schizophrenia.
Ten normal controls and 10 patients diagnosed with schizophrenia were studied using the dual-click procedure. For each single trial, the temporal shift in P50 that yielded the best alignment with the average P50 response was used to derive a measure of P50 temporal variability from trial to trial and to form P50 averages corrected for temporal variability.
Patients with schizophrenia had significantly more temporal variability than normal controls. Correction for temporal variability in the P50 responses increased the size of P50 for both patients with schizophrenia and normal controls. Patients with schizophrenia had smaller P50 responses to the first click than controls and less inhibition to the second click before, but not after, correction for temporal variability.
These findings suggest that temporal variability contributes significantly to the P50 response as measured using the gating procedure. The measure of temporal variability may provide a new index of inhibitory and attentional function in schizophrenia.
注意力和认知缺陷在精神分裂症中很常见。使用听觉双点击范式，多项研究发现，与正常对照组相比，精神分裂症患者在通过对第二次点击的平均P50诱发反应测量重复刺激的抑制或门控方面表现受损。由于收集了许多试验的反应来研究平均反应，每次试验中P50反应时间的波动可能会影响观察到的差异。我们提出了一种计算机化的客观程序，用于评估精神分裂症患者大脑反应的时间变异性。
使用双点击程序对10名正常对照者和10名诊断为精神分裂症的患者进行研究。对于每个单次试验，使用与平均P50反应最佳对齐的P50时间偏移来得出每次试验之间P50时间变异性的测量值，并形成针对时间变异性校正的P50平均值。
精神分裂症患者的时间变异性明显高于正常对照组。对P50反应的时间变异性进行校正后，精神分裂症患者和正常对照组的P50幅度均增加。在对时间变异性进行校正之前，精神分裂症患者对第一次点击的P50反应小于对照组，对第二次点击的抑制作用也较小，但校正后则不然。
这些发现表明，时间变异性对使用门控程序测量的P50反应有显著贡献。时间变异性的测量可能为精神分裂症的抑制和注意力功能提供一个新的指标。
