Pilots used a pacing tool called a tachistoscope that flashed images before their eyes at increasing speeds.
飞行员用一种叫做视速仪的仪器，它能在飞行员眼前快速地闪过敌机。
2
Using the reaction time as the indicator and presenting the stimuli ina tachistoscope, these experiments changed systemically the area and reflectance of the inducing fields.