Varner J L, Rohrbaugh J W
Electrical Engineering Department University of Nebraska-Lincoln.
Biomed Sci Instrum. 1993;29:423-5.
Visual patterns are used to elicit event related potentials. Equipment is available for generating visual geometric patterns such as checkerboards. Slides may be used for patterns which are more complex but preparation is costly and time consuming. A variety of programs exist on PC's for making very elaborate color pictures and in most cases the programs are easy to use making them ideal for generating visual patterns for event related potential experiments. A necessary requirement in event related potential experiments is the ability to control and/or determine precisely when the stimulus is presented to the subject. We have observed that timing is a problem with stimuli generated by the PC as a result of the raster scan and use in many cases of high level system calls in the software. This paper describes a technique which allows for precise control of the time of stimulus presentation using the video control signals to the monitor.
视觉模式用于诱发事件相关电位。有设备可用于生成视觉几何模式，如棋盘格。幻灯片可用于更复杂的模式，但准备成本高且耗时。个人电脑上有各种程序可制作非常精细的彩色图片，在大多数情况下，这些程序易于使用，使其成为生成事件相关电位实验视觉模式的理想选择。事件相关电位实验的一个必要要求是能够精确控制和/或确定何时向受试者呈现刺激。我们观察到，由于光栅扫描以及软件中许多情况下使用高级系统调用，个人电脑生成的刺激存在时间控制问题。本文描述了一种利用发送到显示器的视频控制信号精确控制刺激呈现时间的技术。
