Neuroscience 2005 Abstract
| Presentation Number: | 771.18 |
|---|---|
| Abstract Title: | Semantic contextual effects on neural activities related to word processing during a categorical decision task. |
| Authors: |
Hayakawa, T.*1,2
; Fujimaki, N.1
; Terazono, Y.1
; Matani, A.1
1National Inst. of Information and Communications Technology, Kobe, Japan 2Japan, 588-2, Iwaoka, Iwaoka-cho, Nishi-ku, 651-2492, |
| Primary Theme and Topics |
Cognition and Behavior - Human Cognition, Behavior, and Anatomy -- Language |
| Session: |
771. Language IV Poster |
| Presentation Time: | Tuesday, November 15, 2005 2:00 PM-3:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # OO11 |
| Keywords: | LANGUAGE, MEG, BRAIN IMAGING, COGNITION |
To investigate neural substrate of semantic contextual effects on word processing, MEGs were recorded by related and unrelated prime-target pairs during a categorical decision task. The pair stimuli, which consisted of Japanese katakana (syllabogram) nouns, were arranged into four conditions (category matching x semantically related). All stimuli were presented for 100 ms in the left visual field. After the presentation of prime, a target was presented followed by an inter-stimulus interval of 1000 ms, and then a cue for pressing button was presented at 2000 ms. Subjects were instructed to decide immediately whether the target was in the category or not, and to respond after the cue. A 148-channel whole-head system was used for the MEG measurement, and cortical current distributions were calculated using the minimum norm least square approach and a realistic brain model. The current distribution showed that large activation occurred in the occipital visual areas along the ventral visual processing stream in the right hemisphere (contra lateral to the presented stimuli) at latencies of 100-180 ms and in the anterior temporal area and occipito-temporal junction in the left hemisphere at latencies of 200-600 ms. The occipital and superior parietal areas in the right hemisphere had kept small activities in the later period. After these activations, pre- and post-central gyri were activated at latencies of 1200-1300 ms. For the categorical match condition, magnetic responses around right occipital and left temporal areas were larger for the related trial than for the unrelated trial. Activations around left temporal area were particularly affected when the target did not match the category during the unrelated trial. These results suggest that semantic contextual effects modulate activations not only in the language specific brain area but also in the occipital visual area, and a categorical mismatch modulates activations around the left temporal areas.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
Copyright © 2005-2025 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
