Green Michael Foster, Nuechterlein Keith H, Breitmeyer Bruno
Department of Psychiatry and Biobehavioral Sciences, UCLA, USA.
Int J Methods Psychiatr Res. 2002;11(2):83-9. doi: 10.1002/mpr.126.
Visual masking provides a highly informative means of assessing the earliest stages of visual processing. This procedure is frequently used in psychopathology research, most commonly in the study of schizophrenia. Deficits in visual masking tasks appear to reflect vulnerability factors in schizophrenia, as opposed to the symptoms of the illness. Visual masking procedures are typically conducted on a tachistoscope, which limits standardization across sites, as well as the number of variables that can be examined in a testing session. Although visual masking can be administered on a computer, most methods used so far have had poor temporal resolution and yielded a limited range of variables. We describe the development of a computerized visual masking battery. This battery includes a staircase procedure to establish an individual's threshold for target detection, and a relatively dense sampling of masking intervals. It includes both forward and backward masking trials for three different masking conditions that have been used previously in experimental psychopathology (target location, target identification with high-energy mask, and target identification with low-energy mask).
视觉掩蔽提供了一种评估视觉处理早期阶段的极具信息价值的方法。该程序常用于精神病理学研究，最常见于精神分裂症的研究中。视觉掩蔽任务中的缺陷似乎反映了精神分裂症的易感性因素，而非该疾病的症状。视觉掩蔽程序通常在速示器上进行，这限制了不同研究地点之间的标准化，以及在一次测试中可检查的变量数量。尽管视觉掩蔽可以在计算机上进行，但迄今为止使用的大多数方法时间分辨率较差，且产生的变量范围有限。我们描述了一种计算机化视觉掩蔽测试组的开发情况。该测试组包括一个用于确定个体目标检测阈值的阶梯程序，以及对掩蔽间隔进行相对密集的采样。它包括先前在实验精神病理学中使用过的三种不同掩蔽条件（目标位置、高能掩蔽下的目标识别以及低能掩蔽下的目标识别）的前向和后向掩蔽试验。
