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（auditory cortex）可通过橄榄耳蜗系统（olivocochlear system）对听觉传入神经进行调控，该系统可支配耳蜗内的外毛细胞以及内毛细胞下方的传入神经元。过往针对人类传出活动的研究，大多聚焦于通过噪声刺激对侧耳来评估耳声发射（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。然而，有关听觉通路更高层级区域传出活动的神经生理学机制，目前仍未明确。此外，目前缺乏针对噪声对人类听觉皮层影响的相关研究，尤其是在儿科人群中，这表明有必要在噪声环境下记录迟发性听觉电位（late auditory potentials）。对学龄儿童的听觉传出系统进行评估具有重要意义，因为其具备多项相关功能，例如噪声环境下的选择性注意与信号检测能力，而这些能力与语言及学业技能的发展密切相关。基于上述原因，本研究的目的在于评估噪声对正常听力儿童P300反应的影响。 研究方法：本研究纳入27名年龄介于8至14岁的正常听力儿童，分别在两种实验条件下记录其P300反应：施加对侧白噪声刺激，以及不施加对侧白噪声刺激。 研究结果：施加对侧噪声时，P300潜伏期显著延长；而波幅未出现明显变化。 研究结论：对正常听力的学龄儿童施加对侧白噪声刺激，可延长其P300潜伏期。上述结果表明，在噪声环境下，内侧橄榄耳蜗束的激活可能对P300反应产生影响。