Sanders Abram F J, Kappers Astrid M L
Utrecht University, Helmholtz Instituut, P.O. Box 80000, 3508 TA Utrecht, The Netherlands.
Percept Psychophys. 2006 Oct;68(7):1094-106. doi: 10.3758/bf03193712.
This study explores bimanual curvature discrimination of cylindrically curved, hand-sized surfaces. The setup was designed so that the postures of the observers' left and right arms and hands were thesame as if the observers were holding a large object in their hands. We measured psychometric curves for observers who used active, dynamic touch; these curvatures ranged from 1.18 to 4.05/m. Bimanual discrimination thresholds were found to be between 0.26 and 0.38/m on average; they were in the same range as unimanual thresholds reported in previous studies. Variation of (1) the horizontal distance between the stimuli or (2) the position of the setup had no effect on thresholds. In addition, we found that a number of observers showed discrimination biases in which they judged two physically different curvatures to be equal. Biases were of the same order of magnitude as the thresholds and could be either positive or negative. These biases can possibly be explained by small differences in left and right arm movements, an explanation that is supported by the position dependence of biases for individual observers.
本研究探讨了对圆柱形弯曲、手大小的表面进行双手曲率辨别。实验装置的设计使得观察者左右手臂和手的姿势与他们手中握着一个大物体时相同。我们测量了使用主动动态触觉的观察者的心理测量曲线；这些曲率范围为1.18至4.05/m。发现双手辨别阈值平均在0.26至0.38/m之间；它们与先前研究中报告的单手阈值处于相同范围。（1）刺激之间的水平距离或（2）实验装置的位置变化对阈值没有影响。此外，我们发现许多观察者表现出辨别偏差，即他们将两种物理上不同的曲率判断为相等。偏差与阈值的量级相同，可能为正或负。这些偏差可能可以通过左右手臂运动的微小差异来解释，这一解释得到了个体观察者偏差的位置依赖性的支持。
