Neuroimaging of Metaphor Processing

描述（由申请人提供）：隐喻和其他比喻性语言在语言中经常出现，可以对物体、人或事件进行简洁生动的描述。不能理解比喻语言会对语言的理解和产生产生巨大的影响，并可能导致社会孤立和自尊心下降。即使脑损伤没有导致失语症，比喻性语言处理也会受损。尽管比喻语言在人类交际中的重要性，但大多数语言研究都集中在字面语言上，导致对支持比喻语言的神经基础的理解有限。临床、行为和神经成像研究支持右半球参与隐喻处理。然而，关于隐喻本身是否会引起右半球的参与，或者是否有其他因素在比喻-文字维度上共同变化，从而引起右半球的参与，存在争议。分级显著性假说认为，在处理显著性低的语言时，右脑会进行招募，而在处理显著性高的语言时，左脑会进行招募。两个可能影响显著性和半球招募的因素是语义相关性和语境。本研究的第一个目标是利用功能磁共振成像（fMRI）来研究语义相关性通过操纵隐喻和字面句子的新颖性对半球招募的影响。熟悉短语由于其经常出现的性质，可以在词汇中建立密切的语义关系。相反，新短语需要概念的动态整合。语义关联将通过检查熟悉的和新颖的隐喻，以及包含典型和创新使用对象的句子来操纵。本研究的第二个目的是利用功能磁共振成像（fMRI）研究隐喻和文字语言加工过程中语境对大脑半球招募的影响。语境可以为后续文本的处理提供一个框架。通过在隐喻和字面句中添加相关和不相关的句子语境来操纵显著性。

DESCRIPTION (provided by applicant): Metaphors, and other figurative language, occur frequently in language and can provide a succinct and vivid description of an object, person, or event. Failures in understanding figurative language can have a dramatic impact on language comprehension and production, and can lead to social isolation and decreased self-esteem. Even when brain injuries do not result in aphasia, figurative language processing can be impaired. Despite the importance of figurative language in human communication, most language research focuses on literal language, resulting in a limited understanding of the neural foundation that supports figurative language. Clinical, behavioral, and neuro imaging research support right hemisphere involvement in metaphor processing. However, there is debate over whether it is metaphors per se that engage the right hemisphere or if other factors that co-vary along the figurative-literal dimension elicit right hemisphere engagement. The Graded Salience Hypothesis proposes right hemisphere recruitment when processing language that is low in salience, and left hemisphere recruitment when processing language that is high in salience. Two factors that may influence salience and hemispheric recruitment are semantic relatedness and context. The first goal of this proposal is to use functional magnetic resonance imaging (fMRI) to investigate the influence of semantic relatedness on hemispheric recruitment by manipulating novelty in metaphors and literal sentences. Familiar phrases, by nature of their common occurrence can establish close semantic relationships in the lexicon. In contrast, novel phrases require dynamic integration of concepts. Semantic relatedness will be manipulated by examining familiar and novel metaphors, and sentences containing typical and innovative uses of objects. The second goal of this proposal is to use fMRI to investigate the influence of context on hemispheric recruitment during metaphor and literal language processing. Context can provide a framework which facilitates the processing of subsequent text. Salience will be manipulated by adding related and unrelated sentential context to metaphors and literal sentences. PUBLIC HEALTH RELEVANCE: Public health will benefit from the proposed research by improving our basic knowledge of the neural foundations of metaphor processing and language in general. This research will facilitate our ability to understand and treat children with specific language impairments and adults with acquired language impairments that result from brain damage.