Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
Department of Psychology, Rutgers University, New Brunswick, NJ, USA.
Infancy. 2021 Jan;26(1):47-62. doi: 10.1111/infa.12373. Epub 2020 Oct 27.
Preverbal infants represent the approximate numerosity of visual and auditory arrays: By 6 months old, they reliably discriminate eight dots or tones from 16 (a 1:2 ratio), but not eight from 12 (a 2:3 ratio). The precision of this approximate number sense improves gradually over childhood and into adulthood. However, less is known about numerical abilities in younger infants, and in particular, whether there is developmental change in the number sense in the first half year of life. Here, in four experiments, we measured numerical precision in 4-month-old infants (N = 128) using a visual habituation task comparable to that in studies of older infants. We found that 4-month-olds exhibited poorer numerical discrimination than the 6-month-olds tested in previous studies, dishabituating to a 1:4 change in numerical ratio, but not a 1:3 change. Like older infants, 4-month-olds' numerical precision improved when they were provided with redundant visual and auditory input; when both visual and auditory information were present, 4-month-olds discriminated a 1:3 but not a 1:2 ratio. These results suggest that Approximate Number System precision develops in early infancy and may be sensitive to intersensory redundancy as early as four months of age.
6 个月大时，他们可以可靠地区分 8 个点或音调和 16 个（1:2 的比例），但不能区分 8 个和 12 个（2:3 的比例）。这种近似数量感的精度在儿童期和成年期逐渐提高。然而，对于年幼婴儿的数字能力知之甚少，特别是在生命的前半年是否存在数量感的发展变化。在这里，我们通过与研究较大婴儿的视觉习惯化任务相媲美的视觉习惯化任务，在四个实验中测量了 4 个月大婴儿（N=128）的数字精度。我们发现，4 个月大的婴儿在数字比例上的辨别能力比之前研究中 6 个月大的婴儿差，他们对 1:4 的数字比例变化不适应，但对 1:3 的数字比例变化适应。与较大婴儿一样，4 个月大婴儿的数字精度在提供冗余的视觉和听觉输入时会提高；当同时存在视觉和听觉信息时，4 个月大的婴儿可以区分 1:3 的比例，但不能区分 1:2 的比例。这些结果表明，近似数量系统的精度在婴儿早期发展，并且可能早在 4 个月大时就对感觉冗余敏感。
