Effects of genetic variation in dopamine on language

描述（由申请人提供）：心理语言学中最具争议的问题之一是语言是否可以分为基于规则的系统和基于记忆的系统，即所谓的双系统模型，或者整个系统是否可以包含在一种计算中。这个答案暗示了语言是如何被儿童习得的，如何被成人使用，如何被植入机器，以及如何在脑损伤后修复。这个项目的目的是测试双系统模型及其替代品在一个新的领域：遗传学。根据先前对失语症患者、帕金森氏症患者和健康受试者的神经影像学研究，我们知道，左额叶，特别是左额叶的纹状体-皮质多巴胺能回路，在基于规则的语言过程中发挥作用，但在基于记忆的语言过程中不起作用。我们建议测试编码大脑对多巴胺反应的基因（包括DRD2、DRD4、DAT和COMT）的正常变异是否与基于规则而非基于记忆的语言处理的表现变化相关。一个积极的发现将为双系统模型提供新的证据，并为思考语言的结构和遗传提供新的途径。

DESCRIPTION (provided by applicant): One of the most contentious questions in psycholinguistics is whether language can be divided into separate rule-based and memory-based systems-the so-called dual-system model-or whether, alternatively, the entire system can be subsumed under one kind of computation. The answer has implications for the way language is acquired by children, used by adults, built into machines, and remediated after brain injury. The aim of this project is to test the dual-system model and its alternatives in a novel domain: genetics. Based on previous work using aphasics, Parkinson's patients, and neuroimaging with healthy subjects, it is known that the left frontal lobe, and in particular striato-cortical dopaminergic circuits in the left frontal lobe, play a role in rule-based but not memory-based processes within language. We propose to test whether normal variation in genes that encode the brain's response to dopamine (including DRD2, DRD4, DAT, and COMT) is correlated with variation in performance on rule-based but not memory-based language processing in a large, population-based sample. A positive finding would provide new evidence for the dual-system model as well as suggesting new avenues for thinking about the structure and genetics of language.