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Altered small-world brain networks in temporal lobe in patients with schizophrenia performing an auditory oddball task.

Yu Q, Sui J, Rachakonda S, He H, Pearlson G, Calhoun VD - Front Syst Neurosci (2011)

Bottom Line: The small-worldness values were decreased in both hemispheres in SZ.In addition, SZ showed longer shortest path length and lower global efficiency only in the left task-related networks.These results suggested small-world attributes are altered during the AOD task-related networks in SZ which provided further evidences for brain dysfunction of connectivity in SZ.

View Article: PubMed Central - PubMed

Affiliation: The Mind Research Network Albuquerque, NM, USA.

ABSTRACT
The functional architecture of the human brain has been extensively described in terms of complex networks characterized by efficient small-world features. Recent functional magnetic resonance imaging (fMRI) studies have found altered small-world topological properties of brain functional networks in patients with schizophrenia (SZ) during the resting state. However, little is known about the small-world properties of brain networks in the context of a task. In this study, we investigated the topological properties of human brain functional networks derived from fMRI during an auditory oddball (AOD) task. Data were obtained from 20 healthy controls and 20 SZ; A left and a right task-related network which consisted of the top activated voxels in temporal lobe of each hemisphere were analyzed separately. All voxels were detected by group independent component analysis. Connectivity of the left and right task-related networks were estimated by partial correlation analysis and thresholded to construct a set of undirected graphs. The small-worldness values were decreased in both hemispheres in SZ. In addition, SZ showed longer shortest path length and lower global efficiency only in the left task-related networks. These results suggested small-world attributes are altered during the AOD task-related networks in SZ which provided further evidences for brain dysfunction of connectivity in SZ.

No MeSH data available.


Related in: MedlinePlus

Mean absolute z-score matrices for HCs and SZ. Each figure shows a 95 × 95 square matrix, where each entry indicates the mean strength of the connectivity between each pair of voxels. For comparison, z values corresponding to P = 0.05 are 0.0975 (uncorrected) and 0.118 (FDR corrected). 3D spatial organization of 95 voxels were transformed into 1D alignment organized by slice (z-coordinate). The diagonal running from the upper left to the lower right is intentionally set to zero (L: the left task-related network; R: the right task-related network).
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Figure 2: Mean absolute z-score matrices for HCs and SZ. Each figure shows a 95 × 95 square matrix, where each entry indicates the mean strength of the connectivity between each pair of voxels. For comparison, z values corresponding to P = 0.05 are 0.0975 (uncorrected) and 0.118 (FDR corrected). 3D spatial organization of 95 voxels were transformed into 1D alignment organized by slice (z-coordinate). The diagonal running from the upper left to the lower right is intentionally set to zero (L: the left task-related network; R: the right task-related network).

Mentions: In line with prior findings (Calhoun et al., 2008a,b), group ICA results indicated the most task-related component for HCs and the most task-related component for SZ involving both left and right temporal lobe. Figure 1 displays schematic location of top 95 task-related voxels in both hemispheres selected based on the average of the most task-related component for HCs and the most task-related component for SZ. Figure 2 shows mean absolute Fisher's z-score matrices of partial correlation results for both left and right 95 voxels. Figure A3 shows the histogram for absolute partial correlation (Fisher's z) values of one subject in the left task-related network.


Altered small-world brain networks in temporal lobe in patients with schizophrenia performing an auditory oddball task.

Yu Q, Sui J, Rachakonda S, He H, Pearlson G, Calhoun VD - Front Syst Neurosci (2011)

Mean absolute z-score matrices for HCs and SZ. Each figure shows a 95 × 95 square matrix, where each entry indicates the mean strength of the connectivity between each pair of voxels. For comparison, z values corresponding to P = 0.05 are 0.0975 (uncorrected) and 0.118 (FDR corrected). 3D spatial organization of 95 voxels were transformed into 1D alignment organized by slice (z-coordinate). The diagonal running from the upper left to the lower right is intentionally set to zero (L: the left task-related network; R: the right task-related network).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3037777&req=5

Figure 2: Mean absolute z-score matrices for HCs and SZ. Each figure shows a 95 × 95 square matrix, where each entry indicates the mean strength of the connectivity between each pair of voxels. For comparison, z values corresponding to P = 0.05 are 0.0975 (uncorrected) and 0.118 (FDR corrected). 3D spatial organization of 95 voxels were transformed into 1D alignment organized by slice (z-coordinate). The diagonal running from the upper left to the lower right is intentionally set to zero (L: the left task-related network; R: the right task-related network).
Mentions: In line with prior findings (Calhoun et al., 2008a,b), group ICA results indicated the most task-related component for HCs and the most task-related component for SZ involving both left and right temporal lobe. Figure 1 displays schematic location of top 95 task-related voxels in both hemispheres selected based on the average of the most task-related component for HCs and the most task-related component for SZ. Figure 2 shows mean absolute Fisher's z-score matrices of partial correlation results for both left and right 95 voxels. Figure A3 shows the histogram for absolute partial correlation (Fisher's z) values of one subject in the left task-related network.

Bottom Line: The small-worldness values were decreased in both hemispheres in SZ.In addition, SZ showed longer shortest path length and lower global efficiency only in the left task-related networks.These results suggested small-world attributes are altered during the AOD task-related networks in SZ which provided further evidences for brain dysfunction of connectivity in SZ.

View Article: PubMed Central - PubMed

Affiliation: The Mind Research Network Albuquerque, NM, USA.

ABSTRACT
The functional architecture of the human brain has been extensively described in terms of complex networks characterized by efficient small-world features. Recent functional magnetic resonance imaging (fMRI) studies have found altered small-world topological properties of brain functional networks in patients with schizophrenia (SZ) during the resting state. However, little is known about the small-world properties of brain networks in the context of a task. In this study, we investigated the topological properties of human brain functional networks derived from fMRI during an auditory oddball (AOD) task. Data were obtained from 20 healthy controls and 20 SZ; A left and a right task-related network which consisted of the top activated voxels in temporal lobe of each hemisphere were analyzed separately. All voxels were detected by group independent component analysis. Connectivity of the left and right task-related networks were estimated by partial correlation analysis and thresholded to construct a set of undirected graphs. The small-worldness values were decreased in both hemispheres in SZ. In addition, SZ showed longer shortest path length and lower global efficiency only in the left task-related networks. These results suggested small-world attributes are altered during the AOD task-related networks in SZ which provided further evidences for brain dysfunction of connectivity in SZ.

No MeSH data available.


Related in: MedlinePlus