Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
Dev Psychol. 2013 Jun;49(6):1103-12. doi: 10.1037/a0029472. Epub 2012 Aug 13.
From very early in life, humans can approximate the number and surface area of objects in a scene. The ability to discriminate between 2 approximate quantities, whether number or area, critically depends on the ratio between the quantities, with the most difficult ratio that a participant can reliably discriminate known as the Weber fraction. While developmental improvements in the Weber fraction have been demonstrated for number, the developmental trajectory of improvement in area discrimination remains unknown. Here we investigated whether the development of area discrimination parallels that of number discrimination. We tested forty 3- to 6-year-old children and adults in both a number and an area discrimination task in which participants selected the greater of 2 quantities across a range of ratios. We used formal psychophysical models to derive, for each participant and each age group, the Weber fraction for both number and area discrimination. We found that, like number acuity, area acuity steadily improves during childhood. However, we also found area acuity to be consistently higher than number acuity, suggesting a potential difference in the underlying mechanisms that encode and/or represent approximate area and approximate number. We discuss these findings in the context of quantity processing and its development.
从很小的时候起，人类就能大致估计场景中物体的数量和面积。区分两个近似数量（无论是数量还是面积）的能力，关键取决于数量之间的比例，而参与者能够可靠区分的最困难的比例被称为韦伯分数。虽然已经证明了数量的韦伯分数在发育过程中有所提高，但面积辨别力的发展轨迹仍然未知。在这里，我们研究了面积辨别力的发展是否与数量辨别力的发展平行。我们在数量和面积辨别任务中测试了 40 名 3 至 6 岁的儿童和成年人，参与者在一系列比例中选择两个数量中的较大者。我们使用正式的心理物理模型，为每个参与者和每个年龄组推导出数量和面积辨别力的韦伯分数。我们发现，与数量敏锐度一样，面积敏锐度在儿童时期稳步提高。然而，我们也发现面积敏锐度始终高于数量敏锐度，这表明编码和/或表示近似面积和近似数量的潜在机制存在差异。我们在数量处理及其发展的背景下讨论这些发现。
