The integration of semantic versus world knowledge during on-line sentence comprehension

Persistent Link:
http://hdl.handle.net/10150/280182
Title:
The integration of semantic versus world knowledge during on-line sentence comprehension
Author:
Hald, Lea Ann
Issue Date:
2002
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The current research was aimed at addressing several specific questions regarding the integration of world knowledge during language comprehension. First, what is the time course of the on-line integration of semantic and world knowledge information? Secondly, which are the crucial brain areas involved in these processes? It is a long-standing issue whether or not semantic information is prepackaged into the mental lexicon and therefore more immediately available than world knowledge that is necessary to assign a truth-value to a sentence. Two ERP studies were performed to investigate this question. Subjects were presented with sentences like the following types (critical words are underlined): (a) "Amsterdam is a city that is very old and lively." (Correct); (b) "Amsterdam is a city that is very new and lively." (World Knowledge Violation); (c) "Amsterdam is a city that is very thin and lively." (Semantic Violation). Sentence (b) is semantically well-formed, but not true, when considering the founding date of Amsterdam. In contrast, in sentence (c) the semantics of the noun "city" makes the adjective "thin" not applicable. The question was whether or not the waveforms for (b) would result in an N400 effect with the same latency and topography as a lexical semantic N400-effect (c). The ERP waveforms for both (b) and (c) resulted in a clear and sizable N400 effect, with comparable onset and peak latencies. Additionally, (c), but not (b) resulted in an additional late positivity with a posterior distribution. To address the second issue: what are the crucial brain areas involved in these processes, a fMRI version of the experiment was performed. Results indicated that both (b) and (c) activated the left inferior frontal gyrus. In addition, (c), but not (a) or (b), resulted in activation of the left posterior parietal region. Post-integration processes may be responsible for this differential activation found for the world knowledge and semantic conditions. The results of this research indicate that during on-line sentence comprehension world knowledge information is integrated as quickly as lexical semantic information. The left prefrontal cortex might be involved in this recruitment/integration process.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Language, Linguistics.; Psychology, Cognitive.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Psychology
Degree Grantor:
University of Arizona
Advisor:
Nicol, Janet

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleThe integration of semantic versus world knowledge during on-line sentence comprehensionen_US
dc.creatorHald, Lea Annen_US
dc.contributor.authorHald, Lea Annen_US
dc.date.issued2002en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe current research was aimed at addressing several specific questions regarding the integration of world knowledge during language comprehension. First, what is the time course of the on-line integration of semantic and world knowledge information? Secondly, which are the crucial brain areas involved in these processes? It is a long-standing issue whether or not semantic information is prepackaged into the mental lexicon and therefore more immediately available than world knowledge that is necessary to assign a truth-value to a sentence. Two ERP studies were performed to investigate this question. Subjects were presented with sentences like the following types (critical words are underlined): (a) "Amsterdam is a city that is very old and lively." (Correct); (b) "Amsterdam is a city that is very new and lively." (World Knowledge Violation); (c) "Amsterdam is a city that is very thin and lively." (Semantic Violation). Sentence (b) is semantically well-formed, but not true, when considering the founding date of Amsterdam. In contrast, in sentence (c) the semantics of the noun "city" makes the adjective "thin" not applicable. The question was whether or not the waveforms for (b) would result in an N400 effect with the same latency and topography as a lexical semantic N400-effect (c). The ERP waveforms for both (b) and (c) resulted in a clear and sizable N400 effect, with comparable onset and peak latencies. Additionally, (c), but not (b) resulted in an additional late positivity with a posterior distribution. To address the second issue: what are the crucial brain areas involved in these processes, a fMRI version of the experiment was performed. Results indicated that both (b) and (c) activated the left inferior frontal gyrus. In addition, (c), but not (a) or (b), resulted in activation of the left posterior parietal region. Post-integration processes may be responsible for this differential activation found for the world knowledge and semantic conditions. The results of this research indicate that during on-line sentence comprehension world knowledge information is integrated as quickly as lexical semantic information. The left prefrontal cortex might be involved in this recruitment/integration process.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectLanguage, Linguistics.en_US
dc.subjectPsychology, Cognitive.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplinePsychologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorNicol, Janeten_US
dc.identifier.proquest3073228en_US
dc.identifier.bibrecord.b43471900en_US
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