Green Michael Foster, Mintz Jim, Salveson Dustin, Nuechterlein Keith H, Breitmeyer Bruno, Light Gregory A, Braff David L
Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, California 90024-1759, USA.
Biol Psychiatry. 2003 Jun 15;53(12):1113-9. doi: 10.1016/s0006-3223(02)01813-9.
Visual masking procedures assess very early stages of visual perception. Patients with schizophrenia consistently show deficits on visual masking tasks, and these deficits likely reflect vulnerability to schizophrenia. We conducted two experiments to determine whether visual masking procedures can reveal underlying abnormalities in gamma range oscillations in schizophrenia.
In the first experiment, we conducted nonlinear modeling of visual masking performance data from 89 male schizophrenic patients and 20 male comparison subjects. In the second experiment, electrophysiological recordings of event-related gamma activity were taken during a visual masking task in a subset of eight patients and seven control subjects.
In the first experiment, nonlinear modeling of the performance data revealed evidence of oscillations in the gamma range (30 and 35 Hz) for the comparison group but not patients. In the second experiment, the comparison group, but not the patients, showed a burst of gamma range activity 200-400 msec following target presentation. The difference between patients and comparison subjects in this time period was significant (p <.05).
Visual masking procedures can serve as a probe for underlying gamma range activity, which appears to be aberrant in schizophrenia. Perceptual problems in schizophrenia may, at least in part, be due to a failure to establish and/or maintain gamma range oscillations.
视觉掩蔽程序用于评估视觉感知的非常早期阶段。精神分裂症患者在视觉掩蔽任务中始终表现出缺陷，这些缺陷可能反映了对精神分裂症的易感性。我们进行了两项实验，以确定视觉掩蔽程序是否能揭示精神分裂症患者γ波段振荡的潜在异常。
在第一个实验中，我们对89名男性精神分裂症患者和20名男性对照受试者的视觉掩蔽性能数据进行了非线性建模。在第二个实验中，对8名患者和7名对照受试者的一个子集在视觉掩蔽任务期间进行了事件相关γ活动的电生理记录。
在第一个实验中，性能数据的非线性建模显示对照组在γ波段（30和35赫兹）存在振荡迹象，而患者组没有。在第二个实验中，对照组在目标呈现后200 - 400毫秒出现了γ波段活动爆发，而患者组没有。患者和对照组在这个时间段的差异具有显著性（p <.05）。
视觉掩蔽程序可作为潜在γ波段活动的探测手段，γ波段活动在精神分裂症中似乎异常。精神分裂症中的感知问题可能至少部分是由于未能建立和/或维持γ波段振荡。
