Data from: Contralateral noise stimulation delays P300 latency in school-aged children

Background and objective: The auditory cortex modulates auditory afferents through the olivocochlear system, which innervates the outer hair cells and the afferent neurons under the inner hair cells in the cochlea. Most of the studies that investigated the efferent activity in humans focused on evaluating the suppression of the otoacoustic emissions by stimulating the contralateral ear with noise, which assesses the activation of the medial olivocochlear bundle. The neurophysiology and the mechanisms involving efferent activity on higher regions of the auditory pathway, however, are still unknown. Also, the lack of studies investigating the effects of noise on human auditory cortex, especially in peadiatric population, points to the need for recording the late auditory potentials in noise conditions. Assessing the auditory efferents in schoolaged children is highly important due to some of its attributed functions such as selective attention and signal detection in noise, which are important abilities related to the development of language and academic skills. For this reason, the aim of the present study was to evaluate the effects of noise on P300 responses of children with normal hearing. Methods: P300 was recorded in 27 children aged from 8 to 14 years with normal hearing in two conditions: with and whitout contralateral white noise stimulation. Results: P300 latencies were significantly longer at the presence of contralateral noise. No significant changes were observed for the amplitude values. Conclusion: Contralateral white noise stimulation delayed P300 latency in a group of school-aged children with normal hearing. These results suggest a possible influence of the medial olivocochlear activation on P300 responses under noise condition.

研究背景与目的：听觉皮层经橄榄耳蜗系统（olivocochlear system）调控听觉传入通路，该系统支配耳蜗内的外毛细胞以及内毛细胞下方的传入神经元。既往针对人类传出活动的相关研究多通过噪声刺激对侧耳，评估耳声发射（otoacoustic emissions）的抑制效应，以此评价内侧橄榄耳蜗束（medial olivocochlear bundle）的激活状态。但目前关于听觉通路高级区域传出活动的神经生理学机制仍未明确。此外，现有研究对噪声影响人类听觉皮层的探讨较为匮乏，针对儿科人群的相关研究尤其不足，因此有必要在噪声条件下记录迟发性听觉电位（late auditory potentials）。对学龄儿童的听觉传出通路进行评估具有重要意义，因其相关功能包括噪声环境下的选择性注意与信号检测，而这些能力与语言及学业技能的发展密切相关。本研究的目的即在于探讨噪声对听力正常儿童P300电位（P300）应答的影响。

研究方法：纳入27名年龄8至14岁的听力正常儿童，分别在存在对侧白噪声刺激与无对侧白噪声刺激两种实验条件下记录P300电位。

研究结果：对侧噪声存在时，P300电位潜伏期显著延长，而振幅未出现显著变化。

研究结论：对侧白噪声刺激可使本研究中的学龄听力正常儿童的P300电位潜伏期延迟，上述结果提示，噪声条件下内侧橄榄耳蜗束的激活可能对P300电位应答存在调控作用。