Pierce Russell S, Bian Zhang, Braunstein Myron L, Andersen George J
Visual Cognition and Human Performance Laboratory, Department of Psychology, University of California Riverside, CA, USA.
Front Behav Neurosci. 2013 Feb 20;7:12. doi: 10.3389/fnbeh.2013.00012. eCollection 2013.
We examined the ability of observers to detect the 3D curvature of motion paths when binocular disparity and motion information were present. On each trial, two displays were observed through shutter-glasses. In one display, a sphere moved along a linear path in the horizontal and depth dimensions. In the other display, the sphere moved from the same starting position to the same ending position as in the linear path, but moved along an arc in depth. Observers were asked to indicate whether the first or second display simulated a curved trajectory. Adaptive staircases were used to derive the observers' thresholds of curvature detection. In the first experiment, two independent variables were manipulated: viewing condition (binocular vs. monocular) and type of curvature (concave vs. convex). In the second experiment, three independent variables were manipulated: viewing condition, type of curvature, and whether the motion direction was approaching or receding. In both experiments, detection thresholds were lower for binocular viewing conditions as compared to monocular viewing conditions. In addition, concave trajectories were easier to detect than convex trajectories. In the second experiment, the direction of motion did not significantly affect curvature detection. These results indicate the detection of curved motion paths from monocular information was improved when binocular information was present. The results also indicate the importance of the type of curvature, suggesting that the rate of change of disparity may be important in detecting curved trajectories.
我们研究了观察者在存在双眼视差和运动信息时检测运动路径三维曲率的能力。在每次试验中，通过快门眼镜观察两个显示器。在一个显示器中，一个球体在水平和深度维度上沿直线路径移动。在另一个显示器中，球体从与直线路径相同的起始位置移动到相同的结束位置，但在深度上沿弧线移动。要求观察者指出第一个或第二个显示器是否模拟了弯曲轨迹。使用自适应阶梯法来得出观察者的曲率检测阈值。在第一个实验中，操纵了两个自变量：观察条件（双眼观察与单眼观察）和曲率类型（凹形与凸形）。在第二个实验中，操纵了三个自变量：观察条件、曲率类型以及运动方向是接近还是远离。在两个实验中，与单眼观察条件相比，双眼观察条件下的检测阈值更低。此外，凹形轨迹比凸形轨迹更容易检测。在第二个实验中，运动方向对曲率检测没有显著影响。这些结果表明，当存在双眼信息时，单眼信息对弯曲运动路径的检测得到了改善。结果还表明了曲率类型的重要性，这表明视差变化率在检测弯曲轨迹中可能很重要。
