Lee Chia-Lin, Federmeier Kara D
Department of Psychology, University of Illinois.
J Mem Lang. 2009 Nov;61(4):538-555. doi: 10.1016/j.jml.2009.08.003.
Two event-related potential experiments investigated the effects of syntactic and semantic context information on the processing of noun/verb (NV) homographs (e.g., park). Experiment 1 embedded NV-homographs and matched unambiguous words in contexts that provided only syntactic cues or both syntactic and semantic constraints. Replicating prior work, when only syntactic information was available NV-homographs elicited sustained frontal negativity relative to unambiguous words. Semantic constraints eliminated this frontal ambiguity effect. Semantic constraints also reduced N400 amplitudes, but less so for homographs than unambiguous words. Experiment 2 showed that this reduced N400 facilitation was limited to cases in which the semantic context picks out a nondominant meaning, likely reflecting the semantic mismatch between the context and residual, automatic activation of the contextually-inappropriate dominant sense. Overall, the findings suggest that ambiguity resolution in context involves the interplay between multiple neural networks, some involving more automatic semantic processing mechanisms and others involving top-down control mechanisms.
两项与事件相关电位的实验研究了句法和语义上下文信息对名词/动词（NV）同形异义词（如park）加工过程的影响。实验1将NV同形异义词和匹配的明确词嵌入到仅提供句法线索或同时提供句法和语义限制的上下文中。重复先前的研究，当只有句法信息可用时，与明确词相比，NV同形异义词会引发持续的额叶负波。语义限制消除了这种额叶歧义效应。语义限制也降低了N400波幅，但同形异义词的降低幅度小于明确词。实验2表明，这种N400促进作用的降低仅限于语义上下文选择非主导意义的情况，这可能反映了上下文与上下文不适当的主导意义的残余自动激活之间的语义不匹配。总体而言，研究结果表明，上下文中的歧义消解涉及多个神经网络之间的相互作用，其中一些神经网络涉及更多自动语义加工机制，另一些涉及自上而下的控制机制。
