Takeichi Hiroshige, Taniguchi Keito, Shigemasu Hiroaki
Computational Engineering Applications Unit, Head Office for Information Systems and Cybersecurity (ISC), RIKEN, Wako, Saitama, Japan.
Open Systems Information Science Team, Advanced Data Science Project (ADSP), RIKEN Information R&D and Strategy Headquarters (R-IH), RIKEN, Yokohama, Kanagawa, Japan.
Front Psychol. 2023 Mar 10;14:1082557. doi: 10.3389/fpsyg.2023.1082557. eCollection 2023.
Although shape is effective in processing occlusion, ambiguities in segmentation can also be addressed using depth discontinuity given visually and haptically. This study elucidates the contribution of visual and haptic cues to depth discontinuity in processing occlusion.
A virtual reality experiment was conducted with 15 students as participants. Word stimuli were presented on a head-mounted display for recognition. The central part of the words was masked with a virtual ribbon placed at different depths so that the ribbon appeared as an occlusion. The visual depth cue was either present with binocular stereopsis or absent with monocular presentation. The haptic cue was either missing, provided consecutively, or concurrently, by actively tracing a real off-screen bar edge that was positionally aligned with the ribbon in the virtual space. Recognition performance was compared between depth cue conditions.
We found that word recognition was better with the stereoscopic cue but not with the haptic cue, although both cues contributed to greater confidence in depth estimation. The performance was better when the ribbon was at the farther depth plane to appear as a hollow, rather than when it was at the nearer depth plane to cover the word.
The results indicate that occlusion is processed in the human brain by visual input only despite the apparent effectiveness of haptic space perception, reflecting a complex set of natural constraints.
尽管形状在处理遮挡方面很有效，但视觉和触觉所提供的深度不连续性也可用于解决分割中的模糊性问题。本研究阐明了视觉和触觉线索在处理遮挡时对深度不连续性的作用。
以15名学生为参与者进行了一项虚拟现实实验。单词刺激通过头戴式显示器呈现以供识别。单词的中心部分用放置在不同深度的虚拟色带进行遮挡，使得色带呈现为一种遮挡物。视觉深度线索通过双眼立体视觉呈现或通过单眼呈现缺失。触觉线索通过主动追踪与虚拟空间中的色带位置对齐的真实屏幕外条形边缘来缺失、连续提供或同时提供。比较了不同深度线索条件下的识别性能。
我们发现，尽管两种线索都有助于提高深度估计的置信度，但立体线索下的单词识别效果更好，而触觉线索下则不然。当色带出现在较远深度平面以呈现为中空时，识别性能优于色带出现在较近深度平面以覆盖单词时。
结果表明，尽管触觉空间感知具有明显的有效性，但人类大脑仅通过视觉输入来处理遮挡，这反映了一系列复杂的自然限制。
