NTT Communication Science Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, 243-0198, Japan.
Sci Rep. 2022 Feb 2;12(1):1761. doi: 10.1038/s41598-022-05864-x.
Humans can judge the softness of elastic materials through only visual cues. However, factors contributing to the judgment of visual softness are not yet fully understood. We conducted a psychophysical experiment to determine which factors and motion features contribute to the apparent softness of materials. Observers watched video clips in which materials were indented from the top surface to a certain depth, and reported the apparent softness of the materials. The depth and speed of indentation were systematically manipulated. As physical characteristics of materials, compliance was also controlled. It was found that higher indentation speeds resulted in larger softness rating scores and the variation with the indentation speed was successfully explained by the image motion speed. The indentation depth had a powerful effect on the softness rating scores and the variation with the indentation depth was consistently explained by motion features related to overall deformation. Higher material compliance resulted in higher softness rating scores and these variation with the material compliance can be explained also by overall deformation. We conclude that the brain makes visual judgments about the softness of materials under indentation on the basis of the motion speed and deformation magnitude.
人类可以仅通过视觉线索来判断弹性材料的柔软度。然而，对于影响视觉柔软度判断的因素，我们还没有完全了解。我们进行了一项心理物理学实验，以确定哪些因素和运动特征有助于材料的表观柔软度。观察者观看了材料从顶部表面压入一定深度的视频片段，并报告了材料的表观柔软度。压入的深度和速度被系统地操纵。作为材料的物理特性，顺应性也得到了控制。结果发现，较高的压入速度导致较大的柔软度评分，并且压入速度的变化可以通过图像运动速度来很好地解释。压入深度对柔软度评分有很大的影响，并且压入深度的变化可以通过与整体变形相关的运动特征来一致地解释。较高的材料顺应性导致较高的柔软度评分，并且这些评分与材料顺应性的变化也可以通过整体变形来解释。我们得出结论，大脑根据运动速度和变形幅度来进行压入状态下材料柔软度的视觉判断。
