Ogmen Haluk, Shibata Kazuhisa, Yazdanbakhsh Arash
Laboratory of Perceptual and Cognitive Dynamics, Electrical & Computer Engineering, Ritchie School of Engineering & Computer Science, University of Denver, Denver, CO, United States.
Laboratory for Human Cognition and Learning, RIKEN Center for Brain Science, Wako, Japan.
Front Psychol. 2020 Jan 22;10:3000. doi: 10.3389/fpsyg.2019.03000. eCollection 2019.
We live in a three-dimensional (3D) spatial world; however, our retinas receive a pair of 2D projections of the 3D environment. By using multiple cues, such as disparity, motion parallax, perspective, our brains can construct 3D representations of the world from the 2D projections on our retinas. These 3D representations underlie our 3D perceptions of the world and are mapped into our motor systems to generate accurate sensorimotor behaviors. Three-dimensional perceptual and sensorimotor capabilities emerge during development: the physiology of the growing baby changes hence necessitating an ongoing re-adaptation of the mapping between 3D sensory representations and the motor coordinates. This adaptation continues in adulthood and is quite general to successfully deal with joint-space changes (longer arms due to growth), skull and eye size changes (and still being able of accurate eye movements), etc. A fundamental question is whether our brains are inherently limited to 3D representations of the environment because we are living in a 3D world, or alternatively, our brains may have the inherent capability and plasticity of representing arbitrary dimensions; however, 3D representations emerge from the fact that our development and learning take place in a 3D world. Here, we review research related to inherent capabilities and limitations of brain plasticity in terms of its spatial representations and discuss whether with appropriate training, humans can build perceptual and sensorimotor representations of spatial 4D environments, and how the presence or lack of ability of a solid and direct 4D representation can reveal underlying neural representations of space.
我们生活在一个三维（3D）空间世界中；然而，我们的视网膜接收到的是三维环境的一对二维投影。通过使用多种线索，如视差、运动视差、透视等，我们的大脑能够从视网膜上的二维投影构建出三维世界表征。这些三维表征构成了我们对世界的三维感知，并被映射到我们的运动系统中，以产生精确的感觉运动行为。三维感知和感觉运动能力在发育过程中逐渐出现：成长中婴儿的生理机能发生变化，因此需要不断重新调整三维感觉表征与运动坐标之间的映射。这种适应在成年期仍会持续，并且在成功应对关节空间变化（因生长导致手臂变长）、头骨和眼睛大小变化（且仍能进行精确的眼球运动）等方面相当普遍。一个基本问题是，我们的大脑是否由于生活在三维世界中而天生局限于环境的三维表征，或者相反，我们的大脑可能具有表征任意维度的内在能力和可塑性；然而，三维表征的出现是因为我们的发育和学习发生在三维世界中。在此，我们回顾与大脑可塑性在空间表征方面的内在能力和局限性相关的研究，并讨论通过适当训练，人类是否能够构建空间四维环境的感知和感觉运动表征，以及对坚实而直接的四维表征的能力的有无如何揭示潜在的空间神经表征。
