Social influences on sensorimotor integration of speech production and perception during early vocal learning

婴儿在感知和发出母语声音的能力上表现出巨大的变化 在生命的第一年。我们的概念框架在编码奖励的背景下解释了这种可塑性 在联想学习中起作用的预测误差。我们的研究将测试一个重要的机制 问题：在婴儿中， 不同的社会-声音经验的历史是由咿呀学语与社会-声音的偶然配对来调节的。 照顾者的强化。信号与预测器的偶然配对诱导学习预测， 联想学习模型因此，当看护者的社会-声音奖励取决于婴儿的牙牙学语时， 了解到他们的话语预测伴随着成熟的声音模式的社会强化，并开始 产生模仿看护者提供的语音模式的类似语音的形式。我们将这个社会 强化是在发声发展的最早阶段（6 - 12个月）学习的有力驱动力。 典型听力（TH）婴儿。相比之下，患有先天性听力损失（HL）的婴儿 社会-声音互动的贫乏历史，损害了早期的声音学习。但听到 通过人工耳蜗进行补救，社会声音强化将促进学习超越收益 仅仅是因为听力水平的提高。目的1将检验HL婴儿是较差的发声学习者的假设 因为他们没有从牙牙学语和社会声音奖励的偶然配对中获得同样程度的好处 如婴儿。我们将比较TH和HL婴儿学习产生新的发声形式的能力 基于实验操作：看护者的社会声音强化将是暂时的， 偶然的或随机的。我们预测，咿呀学语的社会-声乐 强化在促进HL婴儿学习更多的语言样模式方面效果较差， 在HL和TH条件下，匹配偶然和随机对照组之间的听力水平。 随后通过接受人工耳蜗植入进行听力补救将促进发声学习 基于咿呀学语的社会声音奖励。一个平行的目标2将测试学习的程度是否 产生目标1中的新声音形式可以预测对这些声音的感知改善。如果社会奖励 基于学习加强感知与产出的整合，那么应变训练应该 提高生产性（目标1）和知觉（目标2）学习。我们预测，特遣队增援将 诱导TH婴儿发声和感知之间的相关性，但将发挥有限的 HL婴儿的影响，与更有限的生产学习的婴儿最低的相关性。整治 人工耳蜗植入后的听力将使社会-声音奖励加强知觉-生产 随着听力水平的提高。这些研究是第一次调查社会因素在 基于预测误差的联想学习中的感觉运动整合。

Infants show dramatic changes in their ability to perceive and produce vocal sounds of their native language over the first year of life. Our conceptual framework interprets this plasticity in the context of encoding reward prediction errors that play a role in associative learning. Our studies will test an important mechanistic question: the extent to which linked perceptual and motor learning of speech-like vocalizations in infants with different histories of social-vocal experience is regulated by contingent pairings of babbling with social-vocal reinforcement by caregivers. Contingent pairings of a signal with a reinforcer induce learning of a prediction in models of associative learning. Thus when social-vocal reward by caregivers is contingent on babbling, infants learn that their utterances predict social reinforcement accompanied by mature vocal patterns and begin to produce speech-like forms that emulate the phonological pattern provided by caregivers. We posit that social reinforcement is a potent driver of learning during the earliest stages of vocal development (6-12 months) in infants with typical hearing (TH). In contrast, infants with congenital hearing loss (HL) will have an impoverished history of social-vocal interactions that impair early vocal learning. However, after hearing remediation via a cochlear implant, social-vocal reinforcement will facilitate learning above and beyond gains due to improved hearing levels alone. Aim 1 will test the hypothesis that HL infants are poorer vocal learners because they do not benefit from contingent pairings of babbling with social-vocal reward to the same extent as TH infants. We will compare the ability of infants with TH versus HL to learn to produce new vocal forms based on experimental manipulations: social-vocal reinforcement by caregivers will be either temporally contingent or random with respect to their infants’ babbling. We predict that babbling-contingent social-vocal reinforcement will be less effective in promoting learning of more speech-like patterns in HL infants, despite matching hearing levels between contingent and random-control groups within both HL and TH conditions. Subsequent remediation of hearing via receipt of a cochlear implant will facilitate vocal production learning based on babbling-contingent social-vocal reward. A parallel Aim 2 will test whether degree of learning to produce the new vocal forms in Aim 1 can predict improved perception of those same sounds. If social-reward based learning strengthens integration between perception and production, then contingent training should improve both productive (Aim 1) and perceptual (Aim 2) learning. We predict that contingent reinforcement will induce correlations between production and perception of vocal sounds in TH infants but will exert limited effects in HL infants, with lowest correlations in infants with more limited production learning. Remediation of hearing following cochlear implantation will enable social-vocal reward to strengthen perception-production links as hearing levels improve. These studies are the first to investigate the role of social factors during sensorimotor integration in the context of prediction-error based associative learning.