在整个生命周期中，胎儿期到青春期早期大脑处于快速发育阶段。婴儿在出生时就表现出惊人的言语学习能力，但是语言感知的脑发育机制尚不清楚。本文针对不同年龄段的具体科学问题，拟阐明生命早期的听知觉发育图谱。

实验一使用包含辅音偏差，声调偏差，基频（F0）偏差和类别偏差的多特征范式（multi-feature paradigm），追踪了植入人工耳蜗的语前聋幼儿的听皮质神经功能，拟阐明生命早期的听知觉发育轨迹。结果发现，随着听觉经验增加，听觉皮层诱发电位（cortical auditory evoked potential, CAEP）显著发展，而保存相对完好的失匹态反应（mismatch response, MMR）只有小幅度的提升。从发育轨迹结果来看，对于CAEP，N1潜伏期呈线性下降，P2幅值、P2潜伏期和N300幅值发展曲线为U型。对于MMR，有2个偏差刺激反应的发展效应显著，声调偏差刺激诱发的MMR的早、晚成分幅值的发展轨迹均为三次函数；类别偏差诱发的早MMR幅值变化为线性，而晚MMR成分幅值为三次函数，且与声调偏差的发育轨迹相位相反。此外，神经行为结果表明，残余听力会影响早期的P2幅值发育，而植入早期声调诱发的MMR晚成分可以显著预测言语行为的变化。

实验二是一个长达五年的纵向追踪研究，使用一系列行为测验对学龄儿童的听觉、言语和音乐功能进行了评估，拟阐明言语习得之后的听知觉和认知能力发展规律。结果发现，听知觉在7至11岁显著发展，且发展速率逐渐减小。认知功能中，只有视觉执行注意和工作记忆呈线性发展趋势，直到11岁达到成人水平。而视觉警觉注意、朝向注意、听觉执行注意和听觉朝向注意在7岁时就已经达到成人水平，且在随后五年没有显著变化。我们的研究结果还表明7-9岁存在认知功能分化，由7岁的认知两因素发展为9岁时的认知四因素，即由一般的认知功能分化为三个特异性认知能力，具体为视觉注意、加工速度和执行功能。交叉滞后面板模型结果表明听觉功能和执行功能存在显著的交叉滞后效应，早期更好的听觉功能往往伴随着后期更好的执行功能。

Throughout the lifespan, the brain showed a rapid development from mid fetal to early adolescence. Newborns showed an extremely surprising readiness for speech learning. However, the developmental mechanism of such a readiness remains unclear. Therefore, the present study aims to clarify the developmental patterns of auditory perception based on the specific scientific questions of different ages.

To draw the developmental trajectory of cortical auditory functions in early life, experiment 1 tracked the auditory brain function of prelingually deaf children with electroencephalogram (EEG) using the multi-feature mismatch paradigm, where listeners passively listened sound sequences including a standard sound (ma1, female voice) and four deviant sounds (consonant deviant, lexical tone deviant, fundamental frequency (F0) deviant and backward speech deviant). We found that cortical auditory evoked potential (CAEP) showed a developmental effect with increasing auditory experience, while mismatch response (MMR), 40-60% of children demonstrated deviance detection (i.e., significant MMR) upon CI activation, with at best moderate improvement with cochlear implant (CI) experiences.

For developmental trajectories of CAEP components for CI children, N1 latency decreased further with increasing CI experiences following a linear trajectory over the examined days, and P2 peak amplitude, latency and N300 amplitude developed following a sharp bell shape. For developmental trajectories of MMRs for CI children, significant development was observed for two out of the four deviants (lexical tone and backward speech). For lexical tone deviant, the amplitude of both early and late MMRs changed following a cubic function with increasing CI experiences. For backward speech deviant, latency developed following a linear trajectory, while peak amplitude changed following a cubic trajectory. Interestingly, there was an anti-phasic oscillatory development of tone and backward deviant.

Furthermore, multivariate linear regression analyses revealed neuro-behavioral relations: With limited CI experiences (< 3 months), P2 amplitude varied with averaged residual hearing of the two ears before implantation; N1 amplitude was significantly predictive of early CI outcome; In contrast, behavioral improvement was predicted by late tone MMR shortly after CI activation.

To draw the developmental trajectory of auditory perception after speech acquirement, experiment 2 conducted a 5-year longitudinal study with 3 assessments (grade 1, grade 2 and grade 5). A series of auditory, language, and music functions were assessed through the three testing sessions. For auditory perceptual skills, all measures (difference thresholds of Frequency Discrimination-fixed, Frequency Discrimination-roving and Time Interval Discrimination) revealed a quadratic trajectory over development (from 7 to 11 years old), slowing down with increasing age. Among the 7 cognitive measures, significant improvements with age were observed for three measures: executive control of visual attention. These 2 measures kept improving with constant development rate against age, reaching adult level at age 11. For the other 4 measures, children showed adult level at age 7, and showed no significant changes from age 7 to 11. Confirmatory factor analysis indicated cognitive function differentiation between grade 1 and grade 3, with a best-fit model for two factors at grade 1 and four factors at grade 3 and 5. Cross-lagged panel models revealed a cross-lagged effect from the early auditory perception to the late executive function was observed.

Using Linear Mixed Model (LME) to modeling longitudinal data, the present study revealed the specific developmental trajectories of auditory perception at different ages: in early life, cortical auditory processing developed rapidly upon CI activation, while the mechanism of mismatch response (MMR) developed independent of hearing experience; development of cortical auditory functions were similar to the developmental patterns of cortical synaptic connections; at school age, auditory perception developed independently before cognitive differentiation and had an influence on executive functions. Moreover, the present longitudinal data showed cortical auditory processing developed after hearing onset, and auditory perception also developed after acquiring speech, which was the basis for the development of advanced cognitions such as language and executive functions, and might be an early intervention target.