Brown Angela M, Lindsey Delwin T, Satgunam Premnandhini, Miracle Jaime A
College of Optometry, The Ohio State University, Columbus, Ohio, USA.
Invest Ophthalmol Vis Sci. 2007 Mar;48(3):1424-34. doi: 10.1167/iovs.06-0718.
To determine what critical immaturity is responsible for the poor binocular stereopsis of human infants.
Infant and adult psychometric functions were measured for detection of stereoscopic depth in a random-texture display. A test stimulus defined by horizontal binocular disparity and a distracter stimulus defined by vertical disparity were used. Adults were tested by direct psychophysical methods at several contrast values, and infants by forced-choice preferential looking at 100% contrast.
Infant stereoacuity matured from unmeasurable at age 12 weeks to 7.9 arc min at 20 weeks, which was still far from the nominal adult value of 5 to 10 arc seconds. In contrast, infant d-max (maximum disparity) was 86.8 minutes at 20 weeks, which was near the adult d-max of 110.6 minutes. The average maximum level of infant performance at 20 weeks was 77% correct, still far below adult performance. When the adult stereogram was low contrast, adult extrafoveal performance was similar to infant performance. Infant and adult stereo performance was predicted quantitatively, using infant and adult monocular performance in detecting the stereogram texture. Infant and adult stereopsis performance approached, but did not reach, the predicted values.
The infantlike performance of adults tested at low contrast and the similarity of infant maximum percentage of correct data relative to the predicted values suggested that the critical immaturity limiting infant stereopsis is the well-known insensitivity of the infant visual system to contrast. This conclusion supports the clinical use of stereopsis as a screening test for bilateral monocular function in infants.
确定导致人类婴儿双眼立体视觉不佳的关键不成熟因素。
测量婴儿和成人在随机纹理显示中检测立体深度的心理测量函数。使用由水平双眼视差定义的测试刺激和由垂直视差定义的干扰刺激。成人通过直接心理物理学方法在几个对比度值下进行测试，婴儿通过在100%对比度下的强迫选择优先注视进行测试。
婴儿的立体视敏度从12周龄时无法测量发展到20周龄时的7.9角分，仍远低于成人标称的5至10角秒的值。相比之下，婴儿在20周龄时的d-最大值（最大视差）为86.8分，接近成人的d-最大值110.6分。20周龄时婴儿表现的平均最高水平为77%正确，仍远低于成人表现。当成人立体图对比度较低时，成人中央凹外的表现与婴儿表现相似。利用婴儿和成人在检测立体图纹理时的单眼表现，对婴儿和成人的立体视觉表现进行了定量预测。婴儿和成人的立体视觉表现接近但未达到预测值。
在低对比度下测试的成人的婴儿样表现以及婴儿正确数据的最大百分比相对于预测值的相似性表明，限制婴儿立体视觉的关键不成熟因素是婴儿视觉系统对对比度的众所周知的不敏感性。这一结论支持将立体视觉作为婴儿双侧单眼功能筛查测试的临床应用。
