Department of Human Perception, Cognition, and Action, Max Planck Institute for Biological Cybernetics, Max-Planck-Ring 8, 72076, Tübingen, Germany.
Sci Rep. 2018 Apr 3;8(1):5483. doi: 10.1038/s41598-018-23838-w.
The perceptual upright is thought to be constructed by the central nervous system (CNS) as a vector sum; by combining estimates on the upright provided by the visual system and the body's inertial sensors with prior knowledge that upright is usually above the head. Recent findings furthermore show that the weighting of the respective sensory signals is proportional to their reliability, consistent with a Bayesian interpretation of a vector sum (Forced Fusion, FF). However, violations of FF have also been reported, suggesting that the CNS may rely on a single sensory system (Cue Capture, CC), or choose to process sensory signals based on inferred signal causality (Causal Inference, CI). We developed a novel alternative-reality system to manipulate visual and physical tilt independently. We tasked participants (n = 36) to indicate the perceived upright for various (in-)congruent combinations of visual-inertial stimuli, and compared models based on their agreement with the data. The results favor the CI model over FF, although this effect became unambiguous only for large discrepancies (±60°). We conclude that the notion of a vector sum does not provide a comprehensive explanation of the perception of the upright, and that CI offers a better alternative.
知觉垂直被认为是由中枢神经系统（CNS）构建的矢量和；通过将视觉系统和身体惯性传感器提供的关于垂直的估计与通常位于头部上方的先验知识相结合。最近的发现还表明，各自感觉信号的权重与它们的可靠性成正比，这与矢量和的贝叶斯解释一致（强制融合，FF）。然而，也有违反 FF 的报告，这表明中枢神经系统可能依赖于单个感觉系统（线索捕获，CC），或者根据推断的信号因果关系选择处理感觉信号（因果推理，CI）。我们开发了一种新颖的替代现实系统，可以独立地操纵视觉和物理倾斜。我们要求参与者（n=36）为各种（不）一致的视觉-惯性刺激组合指示感知的垂直，并根据它们与数据的一致性比较模型。结果支持 CI 模型而不是 FF，尽管只有在较大的差异（±60°）时，这种效果才变得明确。我们得出结论，矢量和的概念不能为垂直知觉提供全面的解释，而 CI 提供了一个更好的选择。
