音高是人类日常生活中无处不在的听觉信号特征，携带情绪、语气、个体健康程度、繁殖资源等多种重要信息，因此良好的音高加工能力不仅是理解语言和音乐的认知基础，还对个体的生存和繁衍具有至关重要的进化意义。随着认知神经科学和大脑信号记录技术的蓬勃发展，无论是动物还是人类研究，近年来都越来越多地关注音高识别能力的认知发展以及神经机制。然而，以往研究对音高识别神经基础的认识往往都局限于听觉皮层，但也有少数研究发现脑岛、顶下小叶、楔前叶和外侧枕叶等脑区对音高识别加工也具有一定贡献。但已有研究大多存在样本量较小、对无关个体差异因素控制不严格、对脑结构指标缺乏全面考察等问题，因而，音高识别加工的神经结构基础至今仍不明确。另外，个体音高识别能力的发展往往受到多种因素的调节：一方面，以往研究发现个体的音高识别能力可能存在性别差异，但由于以往研究往往没有对男性和女性组间进行智力、年龄、主利手、音乐训练经验的匹配，因此研究间难以得到一致的结果，并且缺乏神经结构层面的考察。另一方面，由于音高是组成音乐旋律的重要维度，因此音乐训练、尤其是早期音乐训练对个体的音高识别能力具有显著的影响。然而，以往追踪研究多存在训练内容过于同质化、对个体差异因素缺乏严格控制、可推广性较弱等局限，同时也缺乏对早期训练的远期作用的探讨，因此急需从“训练—脑—行为”的整合研究角度，在严格控制无关变量的情况下，进行大样本横断研究。鉴于此，本研究通过三个研究（四个实验）在汉族大学生样本中探讨了音高识别能力的神经结构基础以及性别和音乐训练经验在行为和脑结构水平上对音高识别能力的影响。研究I（实验一）考察了音高识别能力与脑结构指标（包括灰质皮层厚度和局部脑回指数）的关系。我们在308名（124名男性，184名女性）健康的右利手被试中，根据以往研究锁定了包括双侧颞上回、赫氏回、脑岛、顶下小叶、楔前叶和外侧枕叶在内的6对脑区作为感兴趣区，在每个脑区内分别考察了音高识别能力的皮层结构基础，发现音高识别能力与右侧赫氏回和脑岛区域皮层厚度、外侧枕叶皮层局部脑回指数呈正相关关系，同时与外侧枕叶皮层厚度呈负相关关系。研究II（实验二）考察了音高识别能力及其相关脑结构指标（基于实验一的结果）的性别差异，并检测了脑结构对于行为性别差异的中介效应。我们从308名被试中选取了252名（113名男性和139名女性，性别组间匹配年龄、智力、父母教育程度等指标）未经受音乐训练的被试，考察了音高识别能力的性别差异及相关脑结构基础。研究发现女性与男性相比，具有更强的音高识别能力。音高识别能力的脑结构基础存在性别差异：左侧顶下小叶、右侧脑岛皮层厚度与音高识别能力的关系存在显著的性别差异，而女性上述脑区的皮层厚度均大于男性，但这些存在性别差异脑区（左侧顶下小叶和右侧脑岛）的皮层厚度对性别和音高识别能力的关系不具有中介作用。研究III（实验三和实验四）考察了音乐训练经验对于音高识别能力及其脑结构基础（基于实验一的结果）的影响。首先，实验三考察了有无音乐训练经验对音高识别能力及其神经结构基础的影响，我们以研究一样本中经受过正式音乐训练的48名（8名男性和40名女性）被试作为训练组，同时从未受过音乐训练的260名被试中抽出48名（8名男性和40名女性）与训练组匹配的个体作为非训练组。通过组间比较，我们发现训练组较未训练组具有显著更好的音高识别能力，并且右侧赫氏回脑区皮层厚度更厚，并且该脑区皮层厚度对音乐训练和音高识别能力的关系具有部分中介作用。然后，实验四在训练组样本中又进一步考察了音乐训练起始年龄对于音高识别能力及其神经结构基础（基于实验一的结果）的影响。结果发现，音乐训练起始年龄与音高识别能力呈显著负相关关系，同时与右侧脑岛皮层厚度呈显著正相关关系，但右侧脑岛皮层厚度对音乐训练起始年龄和音高识别能力的关系不具有中介作用。综合以上结果，我们可以看出：1）音高识别能力具有多脑区、多维度的结构基础 ；2）音高识别能力和脑结构机制都存在显著的性别差异； 3）音乐训练、尤其是早期音乐训练经验对于音高识别能力的发展具有重要意义。本研究揭示了调性语言母语人群中音高识别能力个体差异的神经结构机制，并加深了我们对其性别差异及音乐训练效应的认识，为今后音乐教育的改革和创新提供了重要的理论依据。

Pitch, an acoustic signal that is ubiquitous in daily life, serves human beings as a reliable clue for crucial information such as emotion, grammatical mood, individuals’ health and reproductive ability. Our ability to process pitches precisely, therefore, is extremely vital in language comprehension and music appreciation, not to speak of individual survival and reproductive success in an evolutional view. With advances of progresses in cognitive neuroscience and cortical recording techniques, emphasis has been put on cognitive development and neural mechanism of pitch identification (PI) in both animal and human studies. Nevertheless, former researches failed to come to an agreement regarding the neuroanatomical basis of pitch identification due to limitations such as small sample size, potential confounding factors or excluding cortical regions other than auditory cortex. As a matter of fact, the mainstream studies on PI is confined to auditory cortex, while few have reported involvement of insula, inferior parietal lobe, precuneus and lateral occipital lobe in pitch processing. Furthermore, the development of PI could be modulated by multiple factors. On the one hand, the ability of pitch identification could be sexual dimorphic, suggested by studies on gender differences. While in these studies, however, IQ, age, handedness and musical training experience were often unbalanced between female and male participants. Therefore it is reasonable to assume that there is more to understand in terms of gender difference in PI and its underlying brain structural basis. On the other hand, exposure to musical training, especially in early life, could possibly benefit individuals on pitch identification, for pitch is often the most recognizable feature of music. However, onefold training scheme and uncontrolled confounders often lead to poor generalizability of the published longitudinal studies. Hence, future studies shall combine brain images with behavioral and training data to detect the training effect on PI in a large well-controlled cross-sectional sample. Thus, in this thesis we investigated the neural anatomical basis of PI and to what extend gender and musical training could explain the individual differences in PI on behavioral and neural morphological levels by three studies (four experiments) in a large population of Han Chinese college students.In study I (experiment 1) we examined the cortical structural correlates of PI separately in 6 pairs of cortical regions including bilateral superior temporal gyrus, Heschl’s gyrus, insula, inferior parietal lobe, precuneus and lateral occipital lobe, selected based on previous findings, in 308 participants (124 males and 184 females). We found that PI was positively correlated with cortical thickness in right Heschl's gyrus (HG) and right insular cortex, and local gyrification index in right lateral occipital lobe, as well as negatively associated with cortical thickness in right lateral occipital lobe.In study II (experiment 2) gender differences in PI and brain structural indexes associated with PI (based on experiment 1) were detected by comparing 113 male with 139 female participants. Exposure to formal musical training, age, IQ score, parents’ educational levels were matched between male and female groups. Results indicated that females outperformed males on PI and have thicker cortex in left IPL and right insula, where the relationship between cortical thickness and PI was sexual dimorphic. However, the cortical thickness in those regions didn’t mediate the correlation between gender and PI performance. In study III (experiment 3 and 4) we investigated the relationship between musical training experience and PI performance as well as the corresponding brain anatomical indexes (based on experiment 1). First, experiment 3 examined the behavioral and neural anatomical differences between individuals who had received formal musical training (training group, 40 females and 8 males) and those who hadn’t (no-training group, 40 females and 8 males). Again, age, IQ score, parents’ educational levels were matched between training group and no-training group. Results revealed that training group outperformed no-training group on pitch identification and has thicker cortex in right HG compared to no-training group, while cortical thickness in right HG could partially mediate the relationship between musical training and PI. Further investigation (experiment 4) among training group observed that the age of onset of musical training was negatively associated with PI performance and positively associated with cortical thickness in right insula, however, no significant role of the latter structural index was found in mediating the relationship between the age of onset of musical training and PI performance. These results indicated that: 1) Cortical anatomical basis of pitch identification consisted of multiple brain regions; 2) Individuals’ ability and neural anatomical basis of pitch identification was sexually dimorphic; 3) Musical trainings, especially those begin at a younger age is beneficial to the development of pitch identification. This study revealed the neural morphological mechanism of individual difference in PI and have crucial implications for us understanding the role of gender and musical training experience. Our results provide theoretical support for the revolution and innovation in musical education.