Infants' development of joint attention shows significant advances between 9 and 12 months of age, but we still need to learn much more about how infants coordinate their attention with others during this process. The objective of this study was to use eye tracking to systematically investigate how 8- and 12-month-old infants as well as adults dynamically select their focus of attention while observing a social partner demonstrate infant-directed actions. Participants were presented with 16 videos of actors performing simple infant-directed actions from a first-person perspective. Looking times to faces as well as hands-and-objects were calculated for participants at each age, and developmental differences were observed, although all three groups looked more at hands-and-objects than at faces. In order to assess whether visual attention was coordinated with the actors' behaviors, we compared participants looking at faces and objects in response to gaze direction as well as infant-directed actions vs. object-directed actions. By presenting video stimuli that involved continuously changing actions, we were able to document that the likelihood of joint attention changes in both real and developmental time. Overall, adults and 12-month-old infants' visual attention was modulated by gaze cues as well as actions, whereas this was only partially true for 8-month-old infants. Our results reveal that joint attention is not a monolithic process nor does it develop all at once.

中文翻译：

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婴儿共同注意力的时间动态：他人注视提示和手动动作的影响。

婴儿的共同注意力发展显示出9到12个月大的进步，但是我们仍然需要更多地了解婴儿在此过程中如何与他人协调注意力。这项研究的目的是使用眼动追踪系统地调查8个月和12个月大的婴儿以及成年人如何动态地选择关注的焦点，同时观察社交伙伴展示婴儿指导的行为。从第一人称视角向参与者展示了16个演员的视频，这些视频是演员进行的简单的针对婴儿的动作。计算了各个年龄段参与者的面对脸以及手和物体的看时间，并且观察到了发育差异，尽管三组的人看脸和手指的时间都多于脸。为了评估视觉注意力是否与演员的行为相协调，我们比较了参与者根据注视方向以及婴儿定向动作与对象定向动作看脸和物体的情况。通过呈现涉及不断变化的动作的视频刺激，我们能够证明共同注意力的可能性在实时和发育时间内都发生了变化。总体而言，成年人和12个月大婴儿的视觉注意力受到注视提示和动作的调节，而对于8个月大婴儿来说，这仅是部分正确的。我们的结果表明，共同注意不是一个整体的过程，也不是一次全部发展起来的。对象导向的动作。通过呈现涉及不断变化的动作的视频刺激，我们能够证明共同注意力的可能性在实时和发育时间内都发生了变化。总体而言，成年人和12个月大婴儿的视觉注意力受注视提示和动作的调节，而对于8个月大婴儿而言，这仅部分正确。我们的结果表明，共同注意不是一个整体的过程，也不是一次全部发展起来的。对象导向的动作。通过展示涉及不断变化的动作的视频刺激，我们能够证明共同注意力的可能性在实时和发育时间内都发生了变化。总体而言，成年人和12个月大婴儿的视觉注意力受到注视提示和动作的调节，而对于8个月大婴儿来说，这仅是部分正确的。我们的结果表明，共同注意不是一个整体的过程，也不是一次全部发展起来的。