Department of Developmental Psychology and Socialisation, University of Padova, Padova, Italy; Department of Neuroscience, University of Padova, Padova, Italy.
Department of Developmental Psychology and Socialisation, University of Padova, Padova, Italy.
Cognition. 2021 Aug;213:104637. doi: 10.1016/j.cognition.2021.104637. Epub 2021 Mar 6.
Coordinated studies provide evidence that very young infants, like human adults and nonhuman animals, readily discriminate small and large number of visual displays on the basis of numerical information. This capacity has been considerably less studied in the auditory modality. Surprisingly, the available studies yielded mixed evidence concerning whether numerical representations of auditory items in the small number range (1 to 3) are present early in human development. Specifically, while newborns discriminate 2- from 3-syllable sequences, older infants at 6 and 9 months of age fail to differentiate 2 from 3 tones. This study tested the hypothesis that infants can represent small sets more precisely when listening to ecologically relevant linguistic sounds. The aim was to probe 9- to 10-month-olds' (N = 74) ability to represent sound sets in a working memory test. In experiments 1 and 2, infants successfully discriminated 2- and 3-syllable sequences on the basis of their numerosity, when continuous variables, such as individual item duration, inter-stimulus duration, pitch, intensity, and total duration, were controlled for. In experiment 3, however, infants failed to discriminate 3- from 4-syllable sequences under similar conditions. Finally, in experiment 4, infants were tested on their ability to distinguish 2 and 3 tone sequences. The results showed no evidence that infants discriminated these non-linguistic stimuli. These findings indicate that, by means of linguistic sounds, infants can access a numerical system that yields precise auditory representations in the small number range.
协调一致的研究提供了证据，表明非常年幼的婴儿（就像人类成年人和非人类动物一样）能够根据数字信息轻松区分小数量和大数量的视觉显示。在听觉模式中，这种能力的研究要少得多。令人惊讶的是，关于人类在小数量范围内（1 到 3）的听觉项目的数值表示是否存在于早期发展中，现有研究提供了混合证据。具体而言，虽然新生儿可以区分 2 音节和 3 音节序列，但 6 至 9 个月大的婴儿无法区分 2 个和 3 个音调。本研究检验了这样一种假设，即当婴儿听到生态相关的语言声音时，他们可以更准确地表示小集合。目的是在工作记忆测试中探测 9 至 10 个月大的婴儿（N=74）代表声音集合的能力。在实验 1 和 2 中，当控制连续变量（如单个项目持续时间、刺激间持续时间、音高、强度和总持续时间）时，婴儿成功地根据数量区分了 2 音节和 3 音节序列。然而，在实验 3 中，婴儿在类似条件下无法区分 3 音节和 4 音节序列。最后，在实验 4 中，婴儿接受了区分 2 个和 3 个音调序列的能力测试。结果表明，婴儿没有区分这些非语言刺激的证据。这些发现表明，通过语言声音，婴儿可以访问一个数字系统，该系统在小数量范围内产生精确的听觉表示。
