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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

The small-world parameters and efficiency of brain functional networks.(A) The functional networks of all cognitive conditions showed a higher clustering coefficient (Cp) and approximately equal characteristic path length (Lp) compared with the matched random networks (top panel), resulting in normalized Cp > 1 and normalized Lp ≈ 1 (bottom panel). (B) Functional networks exhibited higher local efficiency (Eloc) but approximately identical global efficiency (Eglob) of parallel information transmission compared with matched random networks (top panel), resulting in normalized Eloc > 1 and normalized Eglob ≈ 1 (bottom panel). RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task.
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pone.0132518.g001: The small-world parameters and efficiency of brain functional networks.(A) The functional networks of all cognitive conditions showed a higher clustering coefficient (Cp) and approximately equal characteristic path length (Lp) compared with the matched random networks (top panel), resulting in normalized Cp > 1 and normalized Lp ≈ 1 (bottom panel). (B) Functional networks exhibited higher local efficiency (Eloc) but approximately identical global efficiency (Eglob) of parallel information transmission compared with matched random networks (top panel), resulting in normalized Eloc > 1 and normalized Eglob ≈ 1 (bottom panel). RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task.

Mentions: The brain functional network for each participant across all the three cognitive conditions (RS, VSW and VSD) showed higher Cp but almost identical Lp compared with the comparable random networks (Fig 1A). The random networks were generated using Maslov’s wiring program [43], which have the same number of nodes, edges and degree distribution as the real brain functional networks. Moreover, we also observed that the brain network for each subject showed an economic small-world topology of approximately equivalent parallel information processing of Eglob but a higher fault tolerance of Eloc compared with matched random networks (Fig 1B). In addition, the small-worldness indices, σ, for each participant under the three cognitive conditions were larger than 1 (Table 1). These results indicated that brain functional networks preserved small-world organization under different cognitive conditions, consistent with previous studies [10, 44].


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)

The small-world parameters and efficiency of brain functional networks.(A) The functional networks of all cognitive conditions showed a higher clustering coefficient (Cp) and approximately equal characteristic path length (Lp) compared with the matched random networks (top panel), resulting in normalized Cp > 1 and normalized Lp ≈ 1 (bottom panel). (B) Functional networks exhibited higher local efficiency (Eloc) but approximately identical global efficiency (Eglob) of parallel information transmission compared with matched random networks (top panel), resulting in normalized Eloc > 1 and normalized Eglob ≈ 1 (bottom panel). RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493060&req=5

pone.0132518.g001: The small-world parameters and efficiency of brain functional networks.(A) The functional networks of all cognitive conditions showed a higher clustering coefficient (Cp) and approximately equal characteristic path length (Lp) compared with the matched random networks (top panel), resulting in normalized Cp > 1 and normalized Lp ≈ 1 (bottom panel). (B) Functional networks exhibited higher local efficiency (Eloc) but approximately identical global efficiency (Eglob) of parallel information transmission compared with matched random networks (top panel), resulting in normalized Eloc > 1 and normalized Eglob ≈ 1 (bottom panel). RS: resting-state, VSW: visual stimulus watching task, VSD: visual stimulus decision task.
Mentions: The brain functional network for each participant across all the three cognitive conditions (RS, VSW and VSD) showed higher Cp but almost identical Lp compared with the comparable random networks (Fig 1A). The random networks were generated using Maslov’s wiring program [43], which have the same number of nodes, edges and degree distribution as the real brain functional networks. Moreover, we also observed that the brain network for each subject showed an economic small-world topology of approximately equivalent parallel information processing of Eglob but a higher fault tolerance of Eloc compared with matched random networks (Fig 1B). In addition, the small-worldness indices, σ, for each participant under the three cognitive conditions were larger than 1 (Table 1). These results indicated that brain functional networks preserved small-world organization under different cognitive conditions, consistent with previous studies [10, 44].

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