Gori Monica, Sciutti Alessandra, Jacono Marco, Sandini Giulio, Morrone Concetta, Burr David C
Robotics Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy.
Multisens Res. 2013;26(1-2):53-68. doi: 10.1163/22134808-00002397.
The human visual system is good at discriminating speed but not acceleration. However, as speed is seldom constant, it is important to be able to extract speed in conditions of acceleration and deceleration. We measured visual, tactile and bimodal speed-matching over a wide range of accelerations and decelerations in a 2IFC procedure. Both visual and tactile stimuli were generated on physical wheels etched with a sinusoidal profile. During different experimental sessions the wheels could be seen, or touched, or both. Comparisons between different unimodal and bimodal matched speeds revealed similar integration times for the two modalities, in both cases around one second, suggesting that it occurs at a relatively high level of processing. Bimodal precision of speed discrimination was better than unimodal discrimination, as predicted by the maximum likelihood model of optimal integration.
人类视觉系统擅长辨别速度，但不擅长辨别加速度。然而，由于速度很少是恒定的，因此在加速和减速条件下能够提取速度就很重要。我们在一个二择一的迫选程序中，测量了在广泛的加速度和减速度范围内的视觉、触觉和双模式速度匹配。视觉和触觉刺激均由蚀刻有正弦轮廓的物理轮产生。在不同的实验环节中，轮子可以被看到、触摸到或两者皆可。不同单模式和双模式匹配速度之间的比较显示，两种模式的整合时间相似，在两种情况下都约为一秒，这表明整合发生在相对较高的处理水平。正如最优整合的最大似然模型所预测的那样，速度辨别的双模式精度优于单模式辨别。
