Age of Acquisition effects on sign language development and brain processing

描述(申请人提供)：习得年龄对手语发展和大脑处理的影响第一语言习得的年龄，第一语言习得的年龄，对成人的语言能力和大脑语言处理有持久的影响。本研究以聋人手语习得为模型，考察了聋人手语习得的三个关键阶段 问题。第一语言习得对简单句、复杂句和句间结构的发展有何影响？与年轻时相比，当语言发展在年长时开始时，大脑处理语言的方式是否有所不同？语言发展和大脑语言处理之间有联系吗？语言和神经模拟研究采用了回溯性横断面设计。对美国手语(ASL)的理解和产生进行了研究，以准确率和反应时为依赖指标的句子与图片匹配任务，并对ASL中的图片描述进行了详细的语言学分析。使用匹配-失配设计，结合图片和手势，用脑电地形图和功能磁共振成像研究大脑语言处理。L1 AOA通过测试两个独特的群体进行控制：一个是由ASL签约家庭抚养的聋人被领养者；另一个是聋人移民，他们与听力正常的非签约家庭一起移民到美国后，在学校学习了ASL。这两组人都是在童年早期或晚期习得语言的。比较两组人的语言和大脑语言处理，有助于确定语言发展过程中的输入量是否与第一语言能力对语言和大脑处理的影响相吻合。一组控制组是从婴儿期开始学习ASL的聋人；他们的结果显示，语言和大脑处理模式与婴儿期开始的语言习得有关。第二个对照组是二语学习者，他们的结果显示了在以后的生活中学习二语时大脑处理语言的模式是什么样的。语言假设是，简单的句子结构在任何年龄都可以习得，但复杂的和句间结构在理解和产出方面都不能。大脑处理假说认为，语言习得的早期启动对于左半球的经典语言网络的充分发展是必要的。当语言习得开始较晚时，负责视觉和空间加工的后脑区占主导地位。语言技能的水平被预测与这两种类型的大脑语言处理有关。这一结果将为聋人的临床和教育服务以及语言与大脑发育关系的理论建设提供至关重要的信息。

DESCRIPTION (provided by applicant): Age of acquisition effects on sign language development and brain processing Age of first-language acquisition, L1 AoA, has enduring effects on adult language abilities and brain language processing. Using deaf signers' acquisition of ASL as a model for the critical period for language, this project investigates three questions. How does L1 AoA affect the development of simple compared with complex and inter-sentential structure? Does the brain process language differently when language development begins at older as compared to younger ages? Are there links between language development and brain language processing? The language and neuroimaing studies employ a retrospective, cross-sectional design. Comprehension and production of American Sign Language, ASL, is investigated with sentence-to-picture matching tasks with accuracy and reaction time as dependent measures, and detailed linguistic analyses of picture descriptions given in ASL. Brain language processing is investigated with aMEG and fMRI using match-mismatch designs with pictures and signs. L1 AoA is controlled by testing two unique groups: one is deaf adoptees raised by ASL signing families; the other is deaf immigrants who learned ASL in school after immigrating to the USA with their hearing, non-signing families. Individuals in both groups acquired language in either early or late childhood. Comparing the language and brain language processing of the two groups helps determine if the amount of input during language development mitgates L1 AoA effects on language and brain processing. One control group is deaf adults who learned ASL from infancy; their results show language and brain processing patterns associated with an onset of language acquisition in infancy. A second control group is L2 learners of ASL; their results show what language brain processing patterns look like when a L2 is learned in later life. The language hypotheses are that simple sentence structures can be acquired at any age but that complex and inter-sentential structure cannot, both in comprehension and production. The brain processing hypotheses are that an early onset of language acquisition is necessary for the classic language network in the left hemisphere to develop fully. When the onset of language acquisition is late, posterior regions responsible for visual and spatial processing predominate language processing. Level of language skill is predicted to relate to these two types of brain language processing. The results will provide information crucial for clinical and educational services for the deaf population as well as for theory building about the relation of language to brain development.