Psychophysical investigation of sensitivity to disparity information and of perception of 3D subjective contours in the first year of life

在第一个项目阶段，从2个月大开始，对交叉水平差异的敏感性和对竞争的感知被确定。因此，本研究继续调查了对未交叉水平视差的敏感度（实验1）和提取立体形状的能力（实验2）。实验1将采用经典的自然偏好法和强迫选择偏好法（FPL）测量注视时间。该程序的目的是验证FPL方法在项目第一阶段所证明的优越性。其余的婴儿实验将采用习惯化-不习惯化技术。实验3、4和5关注的是立体深度信息丰富的主观轮廓感知。实验3研究婴儿分辨三维主观轮廓的能力。由于增加了水平视差，3D主观轮廓似乎漂浮在诱导元素的上方或下方。在实验3和4中，将使用Kanisza图的一个变体。实验4使用对象统一范式处理模态完成过程。遮挡面将是一个三维主观轮廓。在实验3和4中，立体深度信号的效果将通过与使用图形指定的主观轮廓的控制条件的比较来测试。实验5研究立体主观轮廓的知觉。与Kanizsa图不同，这些轮廓只能在立体条件下被感知。这种主观轮廓强调了水平视差和半遮挡的影响，即单眼信息对深度和物体相干性的影响。在纵向实验1中，6 - 18周龄的婴儿每周进行一次测试。在剩下的实验中，将对两个年龄组进行测试。第一步，对5-6个月大的婴儿进行评估。如果3-4个月大的婴儿能够表现出关键的表现，随后将对他们进行测试，以评估他们是否也表现出实验能力。否则，将对7-8个月大的婴儿进行调查。将使用一种新开发的自动立体显示器。该显示器配备了一个跟踪系统，该系统也用于眼球跟踪设备。两个摄像头跟随婴儿的眼睛来确定婴儿的确切位置，因此，保持高度连贯的立体效果。

In the first project phase, sensitivity for crossed horizontal disparity and perception of rivalry from 2 months of age onwards were identified. Therefore, the research continues by investigating the onset of sensitivity to uncrossed horizontal disparity (Experiment 1) and the ability to extract stereoscopically defined shapes (Experiment 2).Experiment 1 will apply the classical natural preference method of measuring looking times as well as the forced-choice preferential looking (FPL) method. The goal of this procedure is to validate the superiority of the FPL method demonstrated in the first project phase. The remaining experiments with infants will apply the habituation-dishabituation technique.Experiments 3, 4, and 5 focus on the perception of subjective contours that were enriched by stereoscopic depth information. Experiment 3 investigates infants` ability to discern 3D subjective contours. 3D subjective contours, as a consequence of adding horizontal disparity, appear to float either above or below the inducing elements. In Experiments 3 and 4, a variant of the Kanisza figure will be used.Experiment 4 deals with amodal completion processes using the object unity paradigm. The occluding surface will be a 3D subjective contour. In Experiments 3 and 4, the effect of stereoscopic depth signals will be tested by comparisons with control conditions that use pictorially specified subjective contours.Experiment 5 investigates the perception of stereoscopic subjective contours. Unlike the Kanizsa figure, these contours can be perceived under stereoscopic conditions only. This kind of subjective contours highlights both the impact of horizontal disparity and half occlusions, i.e. monocular information on depth and object coherence.In the longitudinal Experiment 1, infants between 6 and 18 weeks of age will be tested weekly. In the remaining experiments, two age groups will be tested. In the first step, infants 5-6 months of age will be assessed. If they can perform the critical performance, infants 3-4 months of age will be tested subsequently to assess whether they also display the experimental ability. Otherwise, older infants aged 7-8 months, will be investigated.A newly developed autostereoscopic monitor will be employed. This monitor is equipped with a tracking system that is also used in eye-tracking devices. Two cameras follow the infant´s eyes to determine the exact position of the infant and, as a consequence, to maintain a highly coherent stereoscopic effect.