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Activity Number:
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241
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Type:
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Topic Contributed
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Date/Time:
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Tuesday, July 31, 2007 : 8:30 AM to 10:20 AM
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Sponsor:
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WNAR
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| Abstract - #309736 |
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Title:
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How Well Does Structural Equation Modeling (SEM) Reveal Weakened Brain Anatomical Connections? An fMRI Simulation Study
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Author(s):
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Jieun Kim*+ and Barry Horwitz
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Companies:
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National Institutes of Health and National Institutes of Health
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Address:
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4710 Bethesda Ave APT1511, Bethesda, MD, 20814,
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Keywords:
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Structural Equation Modeling ; path coefficients ; effective connectivity ; functional MRI ; delayed match-to-sample task
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Abstract:
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SEM, a well-known statistical technique for brain effective connectivity analysis in functional MRI studies, is often used to study patients. This study investigates whether a damaged brain anatomical connectivity can be revealed by SEM. We applied realistic fMRI generated by a large-scale neural network performing a visual delayed match-to-sample task to SEM. We simulated 20 normal subjects and 20 patients for whom the strength of anatomical connection from inferior temporal (IT) to prefrontal cortex (PFC) was reduced to 20% of its normal value. We found that path coefficients for the IT/PFC connection and all feedback pathways from PFC to other regions were significantly reduced in patients. Thus, although a weakened effective connection can be attributed to a weakened anatomical connection, a reduced effective connection may not always reflect a weakened anatomical connection.
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