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Reconfiguration of the Brain Functional Network Associated with Visual Task Demands.

Wen X, Zhang D, Liang B, Zhang R, Wang Z, Wang J, Liu M, Huang R - PLoS ONE (2015)

Bottom Line: Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness.Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity.Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks.

View Article: PubMed Central - PubMed

Affiliation: Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, China.

ABSTRACT
Neuroimaging studies have demonstrated that the topological properties of resting-state brain functional networks are modulated through task performances. However, the reconfiguration of functional networks associated with distinct degrees of task demands is not well understood. In the present study, we acquired fMRI data from 18 healthy adult volunteers during resting-state (RS) and two visual tasks (i.e., visual stimulus watching, VSW; and visual stimulus decision, VSD). Subsequently, we constructed the functional brain networks associated with these three conditions and analyzed the changes in the topological properties (e.g., network efficiency, wiring-cost, modularity, and robustness) among them. Although the small-world attributes were preserved qualitatively across the functional networks of the three conditions, changes in the topological properties were also observed. Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness. The changes in the task-related topological properties were modulated according to the task complexity (i.e., from RS to VSW and VSD). Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity. Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks. These observations provide further insights into the mechanisms underlying the reconfiguration of the brain network during task performance.

No MeSH data available.


Related in: MedlinePlus

Surface visualization of the brain regions exhibiting significant between-state differences in nodal efficiency for the three comparisons, VSW-RS, VSD-VSW, and VSD-RS.The node size is proportional to the relative significance of each between-state comparison (two-tailed paired t-test, p < 0.05, FDR correction). The node colors indicate the node belonging to the six different modules according to the brain template [35]. Uniformly, we detected significantly increased nodal efficiency between each of the three comparisons, VSW-RS, VSD-VSW, and VSD-RS. RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task. LH (RH), left (right) hemisphere.
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pone.0132518.g004: Surface visualization of the brain regions exhibiting significant between-state differences in nodal efficiency for the three comparisons, VSW-RS, VSD-VSW, and VSD-RS.The node size is proportional to the relative significance of each between-state comparison (two-tailed paired t-test, p < 0.05, FDR correction). The node colors indicate the node belonging to the six different modules according to the brain template [35]. Uniformly, we detected significantly increased nodal efficiency between each of the three comparisons, VSW-RS, VSD-VSW, and VSD-RS. RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task. LH (RH), left (right) hemisphere.

Mentions: At the nodal level, the significant effects of task demands on nodal efficiencies, Enod, were observed in some brain regions. A total of 29 regions were survived using the ANOVA to indicate differences across the three cognitive conditions (p < 0.05, FDR corrected). Post-hoc comparisons revealed that 9 brain regions showed significantly increased Enod in VSW compared with RS, and most of these regions (6 out of 9) were located in the occipital cortex (Fig 4). In addition, 24 regions showed significantly increased Enod in VSD compared with RS, including 8 occipital regions and 10 cerebellum areas (Fig 4). Moreover, the consistently enhanced Enod in VSD was primarily observed in 5 default network regions, 5 cerebellum areas, and 3 frontal-parietal regions compared with VSW (Fig 4). Notably, no region showed significantly decreased Enod in the three pair comparisons (i.e., VSW-RS, VSD-RS, and VSD-VSW), likely reflecting the enhanced local and global efficiencies from RS to VSW, and then to VSD, as described above.


Reconfiguration of the Brain Functional Network Associated with Visual Task Demands.

Wen X, Zhang D, Liang B, Zhang R, Wang Z, Wang J, Liu M, Huang R - PLoS ONE (2015)

Surface visualization of the brain regions exhibiting significant between-state differences in nodal efficiency for the three comparisons, VSW-RS, VSD-VSW, and VSD-RS.The node size is proportional to the relative significance of each between-state comparison (two-tailed paired t-test, p < 0.05, FDR correction). The node colors indicate the node belonging to the six different modules according to the brain template [35]. Uniformly, we detected significantly increased nodal efficiency between each of the three comparisons, VSW-RS, VSD-VSW, and VSD-RS. RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task. LH (RH), left (right) hemisphere.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4493060&req=5

pone.0132518.g004: Surface visualization of the brain regions exhibiting significant between-state differences in nodal efficiency for the three comparisons, VSW-RS, VSD-VSW, and VSD-RS.The node size is proportional to the relative significance of each between-state comparison (two-tailed paired t-test, p < 0.05, FDR correction). The node colors indicate the node belonging to the six different modules according to the brain template [35]. Uniformly, we detected significantly increased nodal efficiency between each of the three comparisons, VSW-RS, VSD-VSW, and VSD-RS. RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task. LH (RH), left (right) hemisphere.
Mentions: At the nodal level, the significant effects of task demands on nodal efficiencies, Enod, were observed in some brain regions. A total of 29 regions were survived using the ANOVA to indicate differences across the three cognitive conditions (p < 0.05, FDR corrected). Post-hoc comparisons revealed that 9 brain regions showed significantly increased Enod in VSW compared with RS, and most of these regions (6 out of 9) were located in the occipital cortex (Fig 4). In addition, 24 regions showed significantly increased Enod in VSD compared with RS, including 8 occipital regions and 10 cerebellum areas (Fig 4). Moreover, the consistently enhanced Enod in VSD was primarily observed in 5 default network regions, 5 cerebellum areas, and 3 frontal-parietal regions compared with VSW (Fig 4). Notably, no region showed significantly decreased Enod in the three pair comparisons (i.e., VSW-RS, VSD-RS, and VSD-VSW), likely reflecting the enhanced local and global efficiencies from RS to VSW, and then to VSD, as described above.

Bottom Line: Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness.Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity.Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks.

View Article: PubMed Central - PubMed

Affiliation: Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, China.

ABSTRACT
Neuroimaging studies have demonstrated that the topological properties of resting-state brain functional networks are modulated through task performances. However, the reconfiguration of functional networks associated with distinct degrees of task demands is not well understood. In the present study, we acquired fMRI data from 18 healthy adult volunteers during resting-state (RS) and two visual tasks (i.e., visual stimulus watching, VSW; and visual stimulus decision, VSD). Subsequently, we constructed the functional brain networks associated with these three conditions and analyzed the changes in the topological properties (e.g., network efficiency, wiring-cost, modularity, and robustness) among them. Although the small-world attributes were preserved qualitatively across the functional networks of the three conditions, changes in the topological properties were also observed. Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness. The changes in the task-related topological properties were modulated according to the task complexity (i.e., from RS to VSW and VSD). Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity. Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks. These observations provide further insights into the mechanisms underlying the reconfiguration of the brain network during task performance.

No MeSH data available.


Related in: MedlinePlus