科学家们最近发现了一个秘密：为什么有些人在失去听力后的许多年里能保持清晰说话的能力。这一日前在线发表在《自然—神经学》期刊上的研究显示，成年时期丧失听力的人能够利用声道的感觉来补偿语言动作的失调。
在一组聋人的下巴运动紊乱时，David Ostry和Sazzad Nasir要求他们说一些简单的语言。最初，受试者出现了弯曲状的下巴运动，但在经过几百次的重复后，他们能够调整自己的语言肌肉动作来减少错误。研究人员发现，聋人和拥有听力的人在接受训练后拥有同样的适应能力。
新工作显示，语言的产生依赖于声道的肌肉、皮肤和软组织的感觉，在成年期失去听力的人能够应用这些非耳朵的输入信号来学会说话。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Neuroscience，11, 1217 - 1222，Sazzad M Nasir，David J Ostry
Speech motor learning in profoundly deaf adults
Sazzad M Nasir1 & David J Ostry1,2
Abstract
Speech production, like other sensorimotor behaviors, relies on multiple sensory inputs—audition, proprioceptive inputs from muscle spindles and cutaneous inputs from mechanoreceptors in the skin and soft tissues of the vocal tract. However, the capacity for intelligible speech by deaf speakers suggests that somatosensory input alone may contribute to speech motor control and perhaps even to speech learning. We assessed speech motor learning in cochlear implant recipients who were tested with their implants turned off. A robotic device was used to alter somatosensory feedback by displacing the jaw during speech. We found that implant subjects progressively adapted to the mechanical perturbation with training. Moreover, the corrections that we observed were for movement deviations that were exceedingly small, on the order of millimeters, indicating that speakers have precise somatosensory expectations. Speech motor learning is substantially dependent on somatosensory input.
1 Department of Psychology, McGill University, 1205 Dr. Penfield Avenue, Montreal, Quebec H3A 1B1, Canada.
2 Haskins Laboratories, 300 George Street, New Haven, Connecticut 06511, USA.
