Experimental Studies on Locomotor Experience

BCS-0002001PI：约瑟夫·坎波斯在过去的几年里，我们发现婴儿开始爬行后，有一段时间会出现非凡的心理变化。这些变化非常广泛，涉及感知、空间理解、积极和消极情绪以及家庭内部的社会互动。这些发现是通过使用各种方法得出的，包括对早期和晚期爬行婴儿、使用步行器的婴儿、有运动障碍的婴儿以及不同文化中的婴儿的研究。虽然研究结果高度暗示，运动经验以某种方式导致了这些变化，但运动的开始可能仅仅是对即将到来的心理变化的成熟预测，运动经验和心理发展之间没有内在的因果联系。拟议的研究旨在澄清这种情况。只有将参与者随机分配到条件下的真正实验才能确保对因果关系的可靠推断。因此，我们将对运动经验在心理发展中的作用进行实验研究。为了进行真正的实验，我们设计了一种电动移动装置(PMD)，这是一种小型电动小车，可以通过操纵杆控制其运动。先前的研究表明，运动前期婴儿实际上可以学习控制这样的PMD。在这些发现的基础上，我们现在随机将婴儿分配到可以自愿控制PMD的条件下，或者像其他匹配的婴儿一样被动地乘坐PMD。来自这笔赠款的资金将允许对这种实验性操纵进行初步调查。为了评估与PMD经验相关的结果，我们将在两项测试中评估婴儿，这两项测试在早期研究中已被证明是运动经验的可靠结果。其中一个结果将决定婴儿对周围光流的体位补偿程度(即视觉本体感觉)，另一个结果将测试对高度的警惕(在所谓的“视觉悬崖”上)。在开始结果测试之前，我们将进行广泛的试点工作，使用视觉本体感觉和视觉悬崖任务的修改，旨在提高婴儿在这两种测试中的反应能力。此外，我们还将开展其他试点工作，以探索婴儿对PMD的控制是否涉及目标导向行动(即自愿停在可以找到母亲的地方)，以及婴儿是否能够学会引导PMD绕过阻碍婴儿达到预期目标的障碍。这项研究对理解婴儿期潜在的发展过渡过程具有重要意义。此外，这项研究还对儿童的自我体验可能如何影响大脑生长和发育的过程和组织产生了影响。

BCS-0002001PI: Joseph Campos Over the past several years, we have discovered a period of extraordinary psychological changes after the infant begins to crawl. These changes are very broad, and involve perception, spatial understanding, positive and negative emotions, and social interactions within the family. These discoveries have come about through the use of a variety of methods, including studies of early and late crawling infants, infants who use walker devices, infants with locomotor handicaps, and infants in different cultures. While yielding findings highly suggestive that locomotor experience in some way causes these changes, it remains possible that the onset of locomotion may serve merely as a maturational forecaster of psychological changes to come, and that there is no intrinsic causal link between locomotor experience and psychological development. The proposed studies are designed to clarify this state of affairs. Only a true experiment involving the random assignment of participants to conditions can ensure confident inference about causation. Consequently, we will conduct such an experimental investigation into the role of locomotor experience on psychological development. To carry out a true experiment, we have devised a Powered Mobility Device (PMD), a small electric-powered cart the movement of which can be controlled by a joystick. Prior studies have shown that prelocomotor infants can, in fact, learn to control such a PMD. Building on these findings, we will now randomly assign infants into conditions in which the infant can voluntarily control the PMD, or passively ride in the PMD in the same way as another matched infant. Funding from this grant will permit preliminary investigation of such an experimental manipulation. To assess outcomes related to PMD experience, we will assess the infants on two tests that have been shown to be robust consequences of locomotor experience in earlier studies. One of these outcomes will determine the extent of infant postural compensation to peripheral optic flow (i.e., visual proprioception), and the other will test wariness of heights (on the so-called "visual cliff"). Prior to initiating the outcome testing, we will conduct extensive pilot work using modifications of the visual proprioception and visual cliff tasks that are designed to increase the responsiveness of infants on both tests. In addition, we will conduct other pilot work to explore whether the control by the infant of the PMD will involve goal-directed action (i.e., voluntary stopping at a location where the mother can be found), and whether the infant can learn to steer the PMD around obstacles that prevent the infant from reaching a desired goal.This study has important implications for understanding the processes underlying developmental transitions in infancy. In addition, the research has implications for how self-produced experiences by a child may affect the course and organization of brain growth and development.