2006 Fiscal Year Final Research Report Summary
An investigation of language processing mechanisms using functional neuroimaging : focus on syntax and words
Project/Area Number |
17320089
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Foreign language education
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Research Institution | Seijo University |
Principal Investigator |
KUBOTA Mikio Seijo University, Faculty of Arts and Literature, Professor, 文芸学部, 教授 (60259182)
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Project Period (FY) |
2005 – 2006
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Keywords | NIRS / linguistic neuroscience / language processing / utterance |
Research Abstract |
There have been no such studies that measure early evoked activity of these biochemical substances, deOxyHb and OxyHb, owing to technical difficulties. Using a continuous-wave method, the 2005 NIRS work investigated whether deOxyHb and OxyHb components during language production might be elicited bilaterally with 40 ms sampling time (25 Hz). Subjects read aloud the sentences presented on the computer screen, in either delayed auditory feedback (DAF) or natural auditory feedback (NAF) sessions. Behavioral results indicated that sentential duration in the DAF session was statistically more prolonged than the NAF in both [s]-and [k]-phoneme types that the sentences start with. The cognitive subtraction method by deducting short-duration from long-duration conditions showed that in the [s]-, but not the [k]-phoneme, types of both sessions, two optical components were elicited by duration differences: the deOxyHb component peaking at around 160 ms after initial-consonant onset, and the OxyH
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b component peaking at approximately 100 ms after vowel prolongation onset. These results suggest that early bilateral activity was measured in the capillary and NIRS can clearly detect different oxygen-exchange patterns depending on phoneme types. The second NIRS study (2006) examined whether deOxyHb and OxyHb components during language production might be elicited bilaterally with 25 ms sampling time (40 Hz). Subjects read aloud the noun phrases presented on the computer screen. There were two conditions in either the [s]-or [k]-types : short vowel-duration and long vowel-duration. In the [s]-type, the phrase started with the [s] phoneme, and the initial consonant of the [k]-type was [k] phoneme. The cognitive subtraction method by deducting short-duration from long-duration conditions showed that in the [s]-type, but not in the [k]-type, prominent optical OxyHb components were elicited bilaterally by vowel duration prolongation : the OxyHb component peaked at around 125 ms after initial-consonant onset, and the deOxyHb component peaked at approximately 175 ms post initial-consonant onset. These results suggest that early bilateral activity was measured in the capillary and that NIRS can clearly detect different oxygen-exchange patterns depending on phoneme types. Less
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Research Products
(4 results)