Social and Statistical Mechanisms of Prelinguistic Vocal Learning

描述（由申请人提供）：婴儿如何学习发出他们的语言的声音？婴儿的发音能力在出生后的第一年发生了巨大的变化。从最早的、不成熟的发声开始，婴儿进步很快，通常在12个月大的时候会说第一个单词。在这个过程中，他们开始产生类似语音的音节，并根据他们的语言环境的语音规则来组织音节序列。虽然第一年的发声成就被很好地描述，但对推动发声发展的变化机制知之甚少。大多数研究都集中在声道的成熟上，但对鸣禽的声音发育的研究发现，发育变化也有社会来源。例如，年轻的雄牛椋鸟（Molothrus ater）依靠雌性的反应将其未成熟的声音塑造成功能性的歌声。基于对鸟类的研究，研究人员的初步研究表明，婴儿可以从照顾者对他们咿呀学语的反应中学习新的发声模式。婴儿如何利用社会反馈来创造新的、更先进的发声方式？这项研究的目的是了解婴儿将语言的语音模式融入他们的声音库的机制。在初步研究的基础上，研究者假设照顾者对婴儿咿呀学语的偶然反应促进了婴儿对其语言语音模式的统计学习。为了验证这一假设，我们将对9个月大的婴儿的语言变异性和时间偶然性进行研究，以评估其对声乐学习的影响。本研究对教育父母为婴儿提供最佳学习环境具有重要意义。了解社会引导学习在言语和语言中的作用，可以帮助父母对婴儿的行为更加敏感，从而促进发展。研究社会对语音发展的影响也有助于言语语言病理学的研究，以及成功和障碍交际发展背后的过程。

DESCRIPTION (provided by applicant): How do infants learn to produce the sounds of their language? The vocal abilities of infants change dramatically over the first year of life. Beginning with the earliest, immature vocalizations, infants make rapid progress, typically producing their first words by 12 months of age. Along the way, they begin to produce speech-like syllables and to structure sequences of syllables in accordance with the phonological rules of their language environment. While the vocal achievements of the first year are well-described, not nearly as much is known about the mechanisms of change that drive vocal development. Most work focuses on the maturation of the vocal tract, but studies of vocal development in songbirds found that there are also social sources of developmental change. For example, young male cowbirds (Molothrus ater) rely on the reactions of females to shape their immature sounds into functional song. Based on the avian work, the investigators' preliminary studies have shown that infants can learn new patterns of vocalizing from caregivers' reactions to their babbling. How do infants use social feedback to create new, more developmentally advanced, vocalizations? The goal of the proposed research is to understand the mechanisms by which infants incorporate the phonological patterns of their language into their vocal repertoires. Based on preliminary studies, the investigators hypothesize that the contingent responses of caregivers to babbling facilitate infants' statistical learning of the phonological patterns of their language. To investigate this hypothesis, the variability and temporal contingency of speech to 9-month-old infants will be manipulated to assess their effects on vocal learning. The proposed research has important implications for educating parents in providing optimal learning environments for their infants. An understanding of the role of socially guided learning in speech and language could be used to help parents to be more sensitive to their infants' behavior in ways that would facilitate development. Investigating social influences on phonological development can also contribute to the study of speech-language pathology and of processes underlying both successful and disordered communicative development. PUBLIC HEALTH RELEVANCE: By illuminating mechanisms by which infants learn to produce the sounds of their language from caregivers' contingent speech, the findings could inform interventions for disordered language development. The results could also be used to help parents and child care providers create social environments that foster and support language growth. Eventually, this research could be used to design preventive programs for infants with a higher risk of language delay (e.g., children with Down Syndrome or SLI).