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Wang Z.,Beijing University of Technology | Wang Z.,Beijing Municipal Laboratory of Brain Informatics | Liu J.,Beijing University of Technology | Liu J.,Beijing Municipal Laboratory of Brain Informatics | And 11 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Brain functional network studies have demonstrated the small-world topology as the nature of large-scale spontaneous brain activity. Studies have also revealed that the temporal coherence of spontaneous activity could be reshaped during task-dependent (or post-task) resting states within local spatial patterns such as task-related and the default-mode networks. However, to our best knowledge, it is still a lack of rigorous investigations that whether the small-world topology of spontaneous intrinsic organization remains robust and stable during different resting states. To address the problem, we recorded blood oxygen level-dependent (BOLD) signals from two rests (namely, pre- and post-task resting states) before and after a simple semantic-matching task, and investigated the preceding task influences on the topology of the large-scale spontaneous intrinsic organization during the post-task resting state. The major findings are that the small-world configuration of spontaneous intrinsic organization remains robust and stable during resting states regardless of preceding task influences. © 2011 Springer-Verlag. Source

Liang P.,Capital Medical University | Liang P.,Beijing University of Technology | Liang P.,Beijing Municipal Laboratory of Brain Informatics | Wang Z.,Capital Medical University | And 5 more authors.
PLoS ONE | Year: 2011

The known regional abnormality of the dorsolateral prefrontal cortex (DLPFC) and its role in various neural circuits in mild cognitive impairment (MCI) has given prominence to its importance in studies on the disconnection associated with MCI. The purpose of the current study was to examine the DLPFC functional connectivity patterns during rest in MCI patients and the impact of regional grey matter (GM) atrophy on the functional results. Structural and functional MRI data were collected from 14 MCI patients and 14 age, gender-matched healthy controls. We found that both the bilateral DLPFC showed reduced functional connectivity with the inferior parietal lobule (IPL), superior/medial frontal gyrus and sub-cortical regions (e.g., thalamus, putamen) in MCI patients when compared with healthy controls. Moreover, the DLPFC connectivity with the IPL and thalamus significantly correlated with the cognitive performance of patients as measured by mini-mental state examination (MMSE), clock drawing test (CDT), and California verbal learning test (CVLT) scores. When taking GM atrophy as covariates, these results were approximately consistent with those without correction, although there may be a decrease in the statistical power. These results suggest that the DLPFC disconnections may be the substrates of cognitive impairments in MCI patients. In addition, we also found enhanced functional connectivity between the left DLPFC and the right prefrontal cortex in MCI patients. This is consistent with previous findings of MCI-related increased activation during cognitive tasks, and may represent a compensatory mechanism in MCI patients. Together, the present study demonstrated the coexistence of functional disconnection and compensation in MCI patients using DLPFC functional connectivity analysis, and thus might provide insights into biological mechanism of the disease. © 2011 Liang et al. Source

Liang P.,Beijing University of Technology | Liang P.,Capital Medical University | Liang P.,Beijing Municipal Laboratory of Brain Informatics | Mei Y.,Beijing University of Technology | And 12 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

In order to study the cognitive neural mechanism of human inductive reasoning, both the positive and negative activation should be combined. However, most studies only focus on the positive activation and the negative activation of inductive reasoning has not been reported. The present study will examine the two aspects simultaneously. Two experimental tasks were designed according to the magnitude of shared attributes: sharing two common attributes (2T) and sharing one common attribute (1T), and rest acted as control task. 2T and 1T tasks are both inductive reasoning tasks. 2T task contains the component of perceptual features' integration, while 1T does not. Fourteen college students participated in this study. It was showed that, as compared to rest condition, induction activated a distributed regions including prefrontal cortex (BA 6, 9, 11, 46, 47), caudate, putamen, thalamus, etc., and these regions were related to task difficulty. This may reflect the important role the prefrontal-striatal-thalamus loop in inductive reasoning. The fMRI result also showed the significant negative activation of the right superior temporal gyrus (BA 22), the left angular gyrus (BA 39), bilateral middle frontal gyrus (BA 8, 9, 10), posterior cingulated cortex (BA 31) in inductive reasoning as compared to rest condition. These results were consistent with previous studies of default mode network. Future work were required to examine if there exist induction specific positive activation network and negative activation network, and what the relationship between the two networks. © 2010 Springer-Verlag. Source

Zhong N.,Beijing University of Technology | Zhong N.,Beijing Municipal Laboratory of Brain Informatics | Zhong N.,Maebashi Institute of Technology | Liang P.P.,Capital Medical University | And 9 more authors.
Science China Life Sciences | Year: 2011

Although much has been known about how humans psychologically perform data-driven scientific discovery, less has been known about its brain mechanism. The number series completion is a typical data-driven scientific discovery task, and has been demonstrated to possess the priming effect, which is attributed to the regularity identification and its subsequent extrapolation. In order to reduce the heterogeneities and make the experimental task proper for a brain imaging study, the number magnitude and arithmetic operation involved in number series completion tasks are further restricted. Behavioral performance in Experiment 1 shows the reliable priming effect for targets as expected. Then, a factorial design (the priming effect: prime vs. target; the period length: simple vs. complex) of event-related functional magnetic resonance imaging (fMRI) is used in Experiment 2 to examine the neural basis of data-driven scientific discovery. The fMRI results reveal a double dissociation of the left DLPFC (dorsolateral prefrontal cortex) and the left APFC (anterior prefrontal cortex) between the simple (period length=1) and the complex (period length=2) number series completion task. The priming effect in the left DLPFC is more significant for the simple task than for the complex task, while the priming effect in the left APFC is more significant for the complex task than for the simple task. The reliable double dissociation may suggest the different roles of the left DLPFC and left APFC in data-driven scientific discovery. The left DLPFC (BA 46) may play a crucial role in rule identification, while the left APFC (BA 10) may be related to mental set maintenance needed during rule identification and extrapolation. © 2011 The Author(s). Source

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