Neuroscience 2002 Abstract
| Presentation Number: | 125.10 |
|---|---|
| Abstract Title: | Synchronization In Active Voxels During Functional Magnetic Resonance Imaging. |
| Authors: |
Laird, A. R.*1
; Rogers, B. P.2
; Bach-Y-Rita, P.3
; Meyerand, M. E.2
1Physics, University of Wisconsin-Madison, Madison, WI 2Medical Physics, University of Wisconsin-Madison, Madison, WI 3Rehabilitation Medicine, University of Wisconsin-Madison, Madison, WI |
| Primary Theme and Topics |
Techniques in Neuroscience - Data analysis, physiological methods, statistics |
| Session: |
125. Data analysis, physiological methods, statistics I Slide |
| Presentation Time: | Sunday, November 3, 2002 3:15 PM-3:30 PM |
| Location: | Room 414B |
| Keywords: | FUNCTIONAL MRI, BRAIN IMAGING |
Typically, functional magnetic resonance imaging (fMRI) data is analyzed using statistical models that rely on linear time series methods. However, studies have shown that the blood-oxygenation-level-dependent (BOLD) contrast may not be a linear response to neural activation. Given that there is a nonlinear component to fMRI data, our understanding of the hemodynamic response may benefit by the use of nonlinear methods. Phase synchronization occurs when a relationship exists between two or more nonlinear oscillators and the instantaneous phases of these oscillators become locked. In order to investigate the occurrence of phase synchronization in fMRI studies, we acquired data on three normal volunteers for motor, visual, and language tasks and performed the standard analysis using SPM’99, which analyzes fMRI data according to the General Linear Model. After the activation maps were created for each of the tasks, we selected 4x4 clusters in the cluster centroids. We then performed the phase synchronization analysis on each of the voxels in the selected cluster in order to determine which voxels were synchronized with the activated cluster. Synchronization maps were created for each initial cluster selected based on the results of the phase synchronization analysis, and all maps were thresholded at p<0.05. We found synchronization occurring within the clusters of activation, but no synchronization between spatially separate clusters among simultaneously active voxels during the same task. This phenomenon, in which several regions are found to exhibit synchronization, but are not synchronized among each other, is referred to as cluster synchronization.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2002 Neuroscience Meeting Planner. Orlando, FL: Society for Neuroscience, 2002. Online.
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