Wang Yuyang, Wu Meiyun, Wu Kun, Liu Haotian, Wu Shinan, Zhang Zhikai, Liu Min, Wei Chaogang, Zhang Yu-Xuan, Liu Yuhe
Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
Department of Otolaryngology Head and Neck Surgery, Hunan Provincial People's Hospital (First Affiliated Hospital of Hunan Normal University), Changsha 610041, China.
Cereb Cortex. 2022 Nov 21;32(23):5438-5454. doi: 10.1093/cercor/bhac025.
Unilateral aural stimulation has been shown to cause massive cortical reorganization in brain with congenital deafness, particularly during the sensitive period of brain development. However, it is unclear which side of stimulation provides most advantages for auditory development. The left hemisphere dominance of speech and linguistic processing in normal hearing adult brain has led to the assumption of functional and developmental advantages of right over left implantation, but existing evidence is controversial. To test this assumption and provide evidence for clinical choice, we examined 34 prelingually deaf children with unilateral cochlear implants using near-infrared spectroscopy. While controlling for age of implantation, residual hearing, and dominant hand, cortical processing of speech showed neither developmental progress nor influence of implantation side weeks to months after implant activation. In sharp contrast, for nonspeech (music signal vs. noise) processing, left implantation showed functional advantages over right implantation that were not yet discernable using clinical, questionnaire-based outcome measures. These findings support the notion that the right hemisphere develops earlier and is better preserved from adverse environmental influences than its left counterpart. This study thus provides, to our knowledge, the first evidence for differential influences of left and right auditory peripheral stimulation on early cortical development of the human brain.
单侧听觉刺激已被证明会导致先天性耳聋患者大脑中的大量皮质重组，尤其是在大脑发育的敏感期。然而，尚不清楚哪一侧的刺激对听觉发育最为有利。正常听力成年人的大脑中，左半球在言语和语言处理方面占主导地位，这导致人们认为右耳植入比左耳植入具有功能和发育优势，但现有证据存在争议。为了验证这一假设并为临床选择提供依据，我们使用近红外光谱法对34名语前聋儿童进行了单侧人工耳蜗植入研究。在控制植入年龄、残余听力和优势手的情况下，植入激活数周乃至数月后，言语的皮质处理既未显示出发育进展，也未显示出植入侧的影响。与之形成鲜明对比的是，对于非言语（音乐信号与噪声）处理，左耳植入显示出比右耳植入更具功能优势，而这一优势在基于问卷的临床结果测量中尚未显现。这些发现支持了这样一种观点，即右半球比左半球发育更早，并且受不利环境影响的程度更小。据我们所知，这项研究首次提供了证据，证明左右耳听觉外周刺激对人类大脑早期皮质发育具有不同影响。
