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ERIC Number: ED513896
Record Type: Non-Journal
Publication Date: 2009
Pages: 151
Abstractor: As Provided
Reference Count: 0
ISBN: ISBN-978-1-1095-7260-5
ISSN: N/A
Meaning Apprehension in the Cerebral Hemispheres
Kandhadai, Padmapriya A.
ProQuest LLC, Ph.D. Dissertation, University of Illinois at Urbana-Champaign
When we hear a word, it is remarkable how we store, activate and rapidly retrieve a vast amount of relevant information within a few hundred milliseconds. This thesis examines how meaning is processed in parallel--but with critical differences--between the two hemispheres of the brain. Event-related brain potentials (ERP) were used to examine multiple aspects of meaning apprehension in the cerebral hemispheres because ERPs provide a continuous multidimensional record of brain activity that can track semantic activation over time and dissociate automatic activation from controlled aspects of meaning apprehension. The first two experiments examined hemispheric differences in the breadth of semantic activation using ambiguous words that possess multiple incompatible meanings, and failed to show significant hemispheric differences in activating and maintaining multiple incompatible meanings. In experiments three and four, associated word pairs of varying associative strengths were used to investigate automatic and controlled aspects of semantic processing; the results strongly suggest that both hemispheres were equally capable of accessing associative information and similarly sensitive to associative strength. Contrary to prominent cognitive neuroscience theories of meaning apprehension, this work shows that the hemispheres exhibit broad similarity in semantic representations and breadth of semantic activation. Instead, the present results suggest that the hemispheres differ in when and how they recruit multiple top-down semantic mechanisms to shape that initial activation over time. For instance, the left hemisphere was better able to employ controlled processes to reorder non-canonical meaning relations. In contrast, the right hemisphere needed more explicit task support to recruit such strategic processes. Furthermore, the present results also revealed a left hemisphere benefit for processing predictable information, suggesting that it was better able to use top-down mechanisms to predict and prepare for likely upcoming words. In sum, this thesis provides evidence for multiple, complementary semantic processes recruited in the cerebral hemispheres and outlines how these mechanisms collectively provide robust tools for rapid language comprehension. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]
ProQuest LLC. 789 East Eisenhower Parkway, P.O. Box 1346, Ann Arbor, MI 48106. Tel: 800-521-0600; Web site: http://www.proquest.com/en-US/products/dissertations/individuals.shtml
Publication Type: Dissertations/Theses - Doctoral Dissertations
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A