Department of Psychology, Pusan National University, Busan, Republic of Korea.
Department of Psychology, Pusan National University, Busan, Republic of Korea.
Cortex. 2023 Sep;166:80-90. doi: 10.1016/j.cortex.2023.05.010. Epub 2023 May 31.
Three-dimensional (3D) depth information is important to estimate object sizes. The visual system extracts 3D depth information using both binocular cues and monocular cues. However, how these different depth signals interact with each other to compute the object size in 3D space is unclear. Here, we aim to study the relative contribution of monocular and binocular depth information to size perception in a modified Ponzo context by manipulating their relations in a virtual reality environment. Specifically, we compared the amount of the size illusion in the following two conditions, in which monocular cues and binocular disparity in the Ponzo context can indicate the same depth sign (congruent) or opposite depth sign (incongruent). Our results show an increase in the amount of the Ponzo illusion in the congruent condition. In contrast, in the incongruent condition, we find that the two cues indicating the opposite depth signs do not cancel out the Ponzo illusion, suggesting that the effects of the two cues are not equal. Rather, binocular disparity information seems to be suppressed and the size judgment is mainly dependent on the monocular depth information when the two cues are in conflict. Our results suggest that monocular and binocular depth signals are fused for size perception only when they both indicate the same depth sign and top-down 3D depth information based on monocular cues contributes more to size perception than binocular disparity when they are in conflict in virtual reality.
三维（3D）深度信息对于估计物体大小很重要。视觉系统使用双目线索和单目线索来提取 3D 深度信息。然而，这些不同的深度信号如何相互作用以计算 3D 空间中的物体大小尚不清楚。在这里，我们旨在通过在虚拟现实环境中操纵它们之间的关系，在修改后的彭佐（Ponzo）背景下研究单目和双目深度信息对大小感知的相对贡献。具体来说，我们比较了以下两种情况下大小错觉的程度：在彭佐（Ponzo）背景中单目线索和双目视差可以指示相同的深度信号（一致）或相反的深度信号（不一致）。我们的结果表明，在一致条件下，彭佐错觉的程度增加。相比之下，在不一致条件下，我们发现两个指示相反深度信号的线索并没有抵消彭佐错觉，这表明这两个线索的效果并不相等。相反，当两个线索相互冲突时，似乎抑制了双目视差信息，大小判断主要依赖于单目深度信息。我们的结果表明，只有当两个线索都指示相同的深度信号时，单目和双目深度信号才会融合用于大小感知，并且当它们在虚拟现实中相互冲突时，基于单目线索的自上而下的 3D 深度信息对大小感知的贡献比双目视差更大。
