Vida Mark D, Wilson Hugh R, Maurer Daphne
McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L8, Canada.
York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada.
Vision Res. 2014 May;98:72-82. doi: 10.1016/j.visres.2014.03.005. Epub 2014 Mar 25.
Adults use the orientation of people's heads as a cue to the focus of their attention. We examined developmental changes in mechanisms underlying sensitivity to head orientation during childhood. Eight-, 10-, 12-year-olds, and adults were adapted to a frontal face view or a 20° left or right side view before judging the orientation of a face at or near frontal. After frontal adaptation, there were no age differences in judgments of head orientation. However, after adaptation to a 20° left or right side view, aftereffects were larger and sensitivity to head orientation was lower in 8- and 10-year-olds than in adults, with no difference between 12-year-olds and adults. A computational model indicates that these results can be modeled as a consequence of decreasing neural tuning bandwidths and decreasing additive internal noise during childhood, and/or as a consequence of increasing inhibition during childhood. These results provide the first evidence that neural mechanisms underlying sensitivity to head orientation undergo considerable refinement during childhood.
成年人会将人们头部的朝向作为其注意力焦点的线索。我们研究了儿童期对头部朝向敏感度的潜在机制的发育变化。8岁、10岁、12岁儿童以及成年人先适应正面人脸视图或向左或向右20°的侧面视图，然后判断处于或接近正面的人脸的朝向。在正面适应后，头部朝向判断方面不存在年龄差异。然而，在适应向左或向右20°的侧面视图后，8岁和10岁儿童的后效更大且对头部朝向的敏感度低于成年人，12岁儿童与成年人之间则没有差异。一个计算模型表明，这些结果可以被模拟为儿童期神经调谐带宽减小和加性内部噪声降低的结果，和/或儿童期抑制作用增强的结果。这些结果提供了首个证据，证明对头部朝向敏感度的潜在神经机制在儿童期会经历相当大的优化。
