fMRI investigations of the functional architecture of the language system

点击翻译按钮获取中文摘要

Language is our signature human cognitive skill. Yet, many critical questions regarding the brain basis of language and the role of specific cortical regions in linguistic behavior remain unanswered. Recent research demonstrated high anatomical and functional variability in human brains, thus suggesting that traditional group analyses - applied in the vast majority of the past language studies - may not be optimal. Over the last few years, I developed new techniques - adopted from fMRI methods that have been successful in vision research - to functionally "localize" brain regions sensitive to high-level linguistic processing. This approach has already yielded some important results. For example, I demonstrated that regions that support high-level linguistic processing show little or no response to several non-linguistic functions that have been previously argued to share cognitive and neural machinery with language, including arithmetic processing, general working memory, general cognitive control or musical processing. Furthermore, I discovered that lexical and syntactic representations are tightly integrated in the human mind and brain: any brain region that is sensitive to word-level meanings is also sensitive to combinatorial (i.e., syntactic and compositional semantic) information. Over the next three years, I will build on these results, as well as on prior work in psycholinguistics and theoretical linguistics, to understand the computations we perform and the representations we build during language processing, and to provide a detailed characterization of the brain regions underlying these computations and representations. My work will remain centered around two fundamental questions about the functional architecture of the language system: i) does language processing engage domain-specific mechanisms or does it rely on more general-purpose machinery; and ii) what is the internal functional organization of the language system? In addition to characterizing the language system in healthy individuals, I am now beginning to examine changes in the cortical organization of language in developmental and acquired language disorders.