摘要
目的:分析掩蔽物的亮度极性以及目标结束与掩蔽物开始之间的时间间隔(interstimulusinterval,ISI)期间显示器屏幕的亮度极性对视觉模式掩蔽的影响。方法:实验于2006-02/05在中南民族大学电信学院脑认知科学实验室进行。对10名大学本科学生视力正常者(含矫正视力)进行了两组视觉模式后向掩蔽实验。①实验所用的刺激物为两类卡片,其中一个为目标卡片,即(a)卡片,卡片中央是一个“人”字(宋体,小3号),卡片背景为白色;另一个为掩蔽物卡片,即(b)卡片,中央为一个方块,方块及其背景的亮度极性在实验中会作相应地改变。②模式掩蔽实验分为两组:视觉模式掩蔽实验1。在该实验中,依次呈现目标与掩蔽物卡片,无ISI间隔。实验分为两项:a掩蔽物卡片中的方块亮度极性为白色,即黑底白块,调节掩蔽物的显示屏数。b掩蔽物卡片中方块亮度极性为黑色,即白底黑块,调节掩蔽物的显示屏数。视觉模式掩蔽实验2。在该实验中,依次呈现目标卡片、ISI、掩蔽物卡片。ISI期间屏幕亮度极性为黑色,掩蔽物卡片为黑底白块。掩蔽物的显示屏数与ISI的屏数同时改变。③实验以被试按空格键开始,屏幕中央出现注视点,掩蔽物卡片呈现屏数为1～6,每变化一次掩蔽物卡片的显示屏数,均要求被试在掩蔽物结束后立即报告出所看见的目标卡片上的汉字,记录识别结果,计算被试对目标的识别率。结果:10名被试结果均符合标准,通过在感觉记忆所维持的时间范围内调节掩蔽物的显示时间以及ISI,实验结果显示:视觉模式掩蔽实验1,掩蔽物为黑底白块,掩蔽物显示屏数为1时,目标识别率为84.53%,随着掩蔽物屏数的增加,目标的识别率逐渐降低,当掩蔽物屏数增加到6屏时,目标识别率约为13.25%,识别率下降显著,目标几乎完全被掩蔽。当掩蔽物为白底黑块时,随着掩蔽物的屏数增多,目标识别率均在87.62%�
AIM： To investigate the effects of mask luminance polarity and monitor＇s luminance polarity during interstimulus interval （ISI） on visual pattern masking.
METHODS： From February to May 2006, the experiment was conducted at Brain Cognitive Science Laboratory, Department of Electronics and Information, South-Central University for Nationalities. Ten undergraduate students with normal eyesight （including corrected vision） were tested in two sets of visual pattern backward masking experiments.（1） The stimulators used in the experiments were two kinds of cards with a character and a square on them respectively, which were called target card with white background and mask card with different backgrounds in different experiments. （2）The visual pattern masking experiments had two sets： visual pattern masking experiment 1： target card and mask card were displayed successively, without ISI. The experiment involved 2 kinds： （1）The luminance polarity of square on mask card was white with black background. The displaying screen number of mask card was changed. （2）The luminance polarity of square on mask card was black with white background. The displaying screen number of mask card was also changed. Visual pattern masking experiment 2： target card, ISI and mask card were displayed successively. The luminance polarity of monitor during ISI was black, and the square on mask card was white with black background. Both ISI and the displaying screen number of mask were changed. （3）The experiment was started with the press of space bar by the testees, who were required to report the characters on target card as soon as the mask was over. The mask card presented the screen number of 1-6 and the identifying outcomes were recorded.
RESULTS： All the 10 students in accordance with the criteria entered the stage of result analysis. The displaying time and ISI of mask were adjusted. The visual pattern masking experiment 1, when the square on mask card was white with black background and the
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2007年第9期1659-1662,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
