Choi Ryne, Feldman Jacob, Singh Manish
Department of Psychology and Rutgers Center for Cognitive Science (RuCCS), Rutgers University, Piscataway, NJ 08854, USA.
Vision (Basel). 2024 Jul 4;8(3):43. doi: 10.3390/vision8030043.
Most existing research on the perception of 3D shape from motion has focused on rigidly moving objects. However, many natural objects deform non-rigidly, leading to image motion with no rigid interpretation. We investigated potential biases underlying the perception of non-rigid shape interpretations from motion. We presented observers with stimuli that were consistent with two qualitatively different interpretations. Observers were shown a two-part 3D object with the smaller part changing in length dynamically as the whole object rotated back and forth. In two experiments, we studied the misperception (i.e., perceptual reinterpretation) of the non-rigid length change to a part. In Experiment 1, observers misperceived this length change as a part orientation change (i.e., the smaller part was seen as articulating with respect to the larger part). In Experiment 2, the stimuli were similar, except the silhouette of the part was visible in the image. Here, the non-rigid length change was reinterpreted as a rigidly attached part with an "illusory" non-orthogonal horizontal angle relative to the larger part. We developed a model that incorporated this perceptual reinterpretation and could predict observer data. We propose that the visual system may be biased towards part-wise rigid interpretations of non-rigid motion, likely due to the ecological significance of movements of humans and other animals, which are generally constrained to move approximately part-wise rigidly. That is, not all non-rigid deformations are created equal: the visual systems' prior expectations may bias the system to interpret motion in terms of biologically plausible shape transformations.
大多数现有的关于从运动中感知三维形状的研究都集中在刚性运动的物体上。然而，许多自然物体是非刚性变形的，这导致图像运动没有刚性的解释。我们研究了从运动中感知非刚性形状解释背后的潜在偏差。我们向观察者呈现了与两种质的不同解释相一致的刺激。向观察者展示了一个由两部分组成的三维物体，当整个物体前后旋转时，较小的部分长度会动态变化。在两个实验中，我们研究了对一个部分的非刚性长度变化的错误感知（即感知重新解释）。在实验1中，观察者将这种长度变化错误地感知为部分方向的变化（即较小的部分被视为相对于较大的部分在铰接）。在实验2中，刺激物相似，只是部分的轮廓在图像中可见。在这里，非刚性长度变化被重新解释为一个相对于较大部分具有“虚幻”非正交水平角度的刚性连接部分。我们开发了一个纳入这种感知重新解释的模型，该模型可以预测观察者的数据。我们提出，视觉系统可能倾向于对非刚性运动进行逐部分刚性解释，这可能是由于人类和其他动物运动的生态意义，它们通常被限制为大致逐部分刚性地运动。也就是说，并非所有的非刚性变形都是一样的：视觉系统的先验期望可能会使系统倾向于根据生物学上合理的形状变换来解释运动。
