摘要
在被动触觉的微差实验中,将三个点沿一条想象的水平直线排开,其中间的一个点处于外侧两点间想象的连线的中点位置,但向上或向下稍微偏离该线。安排五个作业,按外侧两点间的不同距离而区分。实验时刺激在右食指第一节腹侧表面通过,但手保持不动,实验应用三种不同的刺激速度。根据对偏离想象直线的75%的正确判定来确定阈限。这种微差的辨别阈限低于通常的两点阈并在多数情况下低于触觉定位阈限。在同一作业内,不同的刺激速度没有不同的作用。但在同一速度下,外侧两点间距离大的,其中间一点的辨别阈限较高,反之则较低,作者对微差作业的特点作了分析并从结构效应的角度讨论了实验结果.
In the experiment with LudvighTarget,the stimuli moved across thesurface of the index finger pad,whilethe finger remained immobile.Threestimulus speeds used were 6.3mm/sec,8.3mm/sec and 12.5mm/sec.The dis-tance betweeb the outer two dots was10,14,18,22 and 26mm respectively.Six subjects were tested by means ofthe method of forced choice,with thetask to say whether the third middledot,variable in its position,was in orout of the imaginery horizontal linebetween the outer two.The thresholdwas defined as the stimulus valuewhich gave rise to 75% correct“out”responding.The basic findings were asfollows:1.The thresholds of LudvighTarget,ranged form 0.632 to 1.938mm,were much smaller than that of Two-Point Limen and of Point Localizationin most cases.2.In terms of eachtwe outer-dot separation,the thresh-olds,at three different speeds,had noSignificant diffirence.3.In terms ofeach stimulus speed,the larger the dis-tance between the two outer dots,thehigher the threshold,and vice versa.
基金
国家自然科学基金
