Neural predictors of individual differences in speech perception

语音感知将声音映射成意义。在发展过程中，对意义重要的声音差异比那些不重要的声音差异在感知上变得更加突出。令人惊讶的是，成年人在感知属于同一语言类别的不同声音的能力上表现出很大的差异。尽管有大量证据表明这种多样性，但神经生物学和言语感知行为的研究很少考虑到这种感知多样性。这个项目将解决这些问题。在一组不同的年轻人中，涉及语言感知的大脑系统将被研究，从脑干到皮层。具体来说，这个项目将测试神经编码的变化预测语言感知和理解的个体差异的理论。这些研究可能为嘈杂环境下的听力或致残障碍的治疗提供新的解决方案。通过公众宣传，该项目将促进语音感知的神经科学，并提高人们对语音感知在教育和劳动力中的重要性的认识。语音感知将一组复杂的声音映射到有限数量的语音类别。类别感知使听者能够通过提高对跨类别边界的声学差异的敏感性和降低类别内的敏感性来应对语音中的声学变异性。个体在“范畴性”上表现出相当大的差异，即对语音类别内声学变化的敏感程度。尽管有大量证据表明分类中存在个体差异（IDs），但人们对IDs与神经处理流或其他言语和语言行为测量的关系知之甚少。目前的项目测试了一个假设，即语音感知中的id来自从脑干到皮层的神经处理流中的id。该项目研究了年轻人（n=100）在听觉通路的早期水平的神经处理，使用听觉脑干反应（ABR）来测量；以及用功能磁共振成像测量的皮质水平。这些任务包括对可能导致声音和言语表现的个体差异的因素的行为测量，比如音乐技能和阅读能力的测量。ABR、fMRI和行为的结合将把语音处理中的id与脑干中声音编码的神经精度和皮层中语音反应的神经特异性联系起来。它还将阐明感知和神经编码中的id如何解释已建立的语音和语言度量中的id。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Speech perception maps sounds into meaning. During development, sound differences important to meaning become more perceptually salient than those that are unimportant. Surprisingly, adults show wide variability in the ability to perceive differences between sounds that belong to the same speech category. Despite considerable evidence for this variability, studies of the neurobiology and behavior of speech perception rarely take this perceptual diversity into account. This project will tackle these questions. In a diverse group of young adults, the brain systems involved in speech perception will be studied, from the brainstem to the cortex. Specifically, this project will test the theory that variation in neural encoding predict individual differences in speech perception and comprehension. These studies may indicate novel solutions for hearing in noisy environments or for treatments for disabling disorders. Through public outreach, this project will promote the neuroscience of speech perception, and foster awareness of the importance of speech perception in education and for the workforce. Speech perception maps a complex set of sounds to a limited number of phonetic categories. Categorical perception enables the listener to cope with acoustic variability in speech, by heightening sensitivity to acoustic differences across category boundaries, and lessening sensitivity within categories. Individuals show sizeable differences in “categoricity,” the degree of sensitivity to acoustic variability within a speech sound category. Despite considerable evidence of individual differences (IDs) in categoricity, little is known of how IDs relate to the neural processing stream or to other behavioral measures of speech and language. The current project tests the hypothesis that IDs in speech perception arise from IDs in the neural processing stream, from brainstem to cortex. The project studies the neural processing of younger adults (n=100) at early levels of the auditory pathway, measured using the auditory brainstem response (ABR); and at cortical levels, measured using fMRI. The tasks include behavioral measures of factors that may drive individual differences in sound and speech representation, such as musical skill and measures of reading ability. The combination of ABR, fMRI, and behavior will link IDs in speech processing to neural precision in sound encoding in the brainstem and neural specificity for phonetic responses in cortex. It will also elucidate how IDs in perception and neural encoding explain IDs in well-established speech and language metrics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.