Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
J Neurosci. 2012 Jul 18;32(29):9859-69. doi: 10.1523/JNEUROSCI.5528-11.2012.
How does visual perception shape the way we coordinate movements? Recent studies suggest that the brain organizes movements based on minimizing reaching errors in the presence of motor and sensory noise. We present an alternative hypothesis in which movement trajectories also result from acquired knowledge about the geometrical properties of the object that the brain is controlling. To test this hypothesis, we asked human subjects to control a simulated kinematic linkage by continuous finger motion, a completely novel experience. This paradigm removed all biases arising from influences of limb dynamics and past experience. Subjects were exposed to two different types of visual feedback; some saw the entire simulated linkage and others saw only the moving extremity. Consistent with our hypothesis, subjects learned to move the simulated linkage along geodesic lines corresponding to the geometrical structure of the observed motion. Thus, optimizing final accuracy is not the unique determinant of trajectory formation.
视觉感知如何塑造我们协调运动的方式？最近的研究表明，大脑根据在存在运动和感觉噪声的情况下最小化到达误差来组织运动。我们提出了一个替代假设，即运动轨迹也是基于大脑控制的物体的几何属性的习得知识而产生的。为了检验这一假设，我们要求人类受试者通过连续的手指运动来控制一个模拟的运动链，这是一种全新的体验。这种范式消除了由于肢体动力学和过去经验的影响而产生的所有偏差。受试者接触到两种不同类型的视觉反馈；一些人看到了整个模拟的连接，而另一些人只看到了移动的末端。与我们的假设一致，受试者学会了沿着与观察到的运动的几何结构相对应的测地线移动模拟的连接。因此，优化最终精度并不是轨迹形成的唯一决定因素。
