Development of Eye-Hand Coordination in Infant Reaching

描述（由申请人提供）：标志着婴儿在生命第一年的出现和发展的步骤通常被认为是由于运动计划和执行背后的视觉运动过程的变化。例如，先前的研究表明，在早期阶段，婴儿依靠视觉来控制和引导他们的手到达预定的目标。然后，随着手部视觉引导的下降，婴儿越来越多地使用视觉来识别物体特征，并在接触前预测手的形状和轨迹。然而，最近的发现对这些解释提出了质疑。研究发现，在早期阶段，婴儿可以在黑暗中伸手，这表明他们不需要看到自己的手来引导它到达目标。而且，其他研究发现，在较晚的阶段，婴儿会退回到与物体无关的触摸配置，就好像他们不再关注物体的物理特征，失去了之前的预测触摸技能。鉴于这些最近的发现，我们还不清楚视觉运动过程是如何促进第一年伸手能力的出现和发展的。由于以前的研究没有提供婴儿在伸手时眼球运动的直接测量，因此很难准确地理解视力如何有助于婴儿的运动计划和执行。

DESCRIPTION (provided by applicant): The steps marking the emergence and development of infant reaching in the first year of life have often been thought to result from changes in the visual-motor processes underlying the planning and execution of movements. For instance, previous accounts proposed that, at the early stages, infants relied on vision to control and guide their hand to the intended goal. Then, as visual guidance of the hand declined, infants used vision increasingly to identify object characteristics and predict the configuration and trajectory of their hand before contact. Recent discoveries, however, have questioned these interpretations. Studies have found that, at the early stages, infants can reach in the dark, suggesting that they do not need to see their hand to guide it to the target. And, other studies have found that at the later stages, infants regress to non-object-related reaching configurations as if they stopped attending to object physical characteristics and lost previous predictive reaching skills. In the light of these recent findings, it has become unclear how visual motor processes contribute to the emergence and development of reaching in the first year. Because previous research has omitted providing direct measures of infant eye movements during reaching it is difficult to understand exactly how vision contributes to movement planning and execution in infancy. The present proposal aims to perform direct measures of infant visual patterns before, during, and after the act of reaching in the 1st year in order to determine whether, when, and how vision is used in the formation and development of reaching. Specifically, experiments will simultaneously acquire precise patterns of eye movements and arm kinematics in one group of infants followed longitudinally over the 1st year and in one group of adult controls. Recordings will be obtained while infants and adults are reaching for objects varying in size and orientation, and while they are simply looking at these objects without reaching. Eye-scanning patterns and point of regard will be compared across age, groups, and object conditions, and will be mapped onto patterns of reaching. These data will allow to determine what information is attended to before and during reaching, and also when not planning to reach. From these data, hypotheses regarding the processes underlying the development of infants' eye-hand coordination in the 1st year will be assessed.