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ABSTRACT: The biological model of extraversion and neuroticism identified by Eysenck has stimulated increasing interest in uncovering neurobiological substrate of the two fundamental dimensions. Here we aim to explore brain disturbances underlying extraversion and neuroticism in 87 healthy individuals using fractional amplitude of low-frequency fluctuations (LFF) on resting-state functional magnetic resonance imaging. Two different frequency bands, Slow-5 (0.01-0.027 Hz) exhibiting higher power and involving larger brain regions, and Slow-4 (0.027-0.073 Hz) exhibiting less power and emerging locally, were analyzed. Our results showed a positive correlation between LFF amplitude at Slow-5 and extraversion in medial prefrontal cortex and precuneus, important portions of the default mode network, thus suggesting a link between default network activity and personality traits. LFF amplitude at Slow-5 was correlated positively with neuroticism in right posterior portion of the frontal lobe, further validating neuroticism with frontal lateralization. In addition, LFF amplitude at Slow-4 was negatively associated with extraversion and neuroticism in left hippocampus (HIP) and bilateral superior temporal cortex (STC) respectively, supporting the hypothesized (inverse) relationship between extraversion and resting arousal, also implying neural circuit underlying emotional process influencing on personality. Overall, these findings suggest the important relationships, between personality and LFF amplitude dynamic, depend on specific frequency bands. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc.
Human Brain Mapping 09/2012; · 5.88 Impact Factor
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ABSTRACT: The superior capability of chess experts largely depends on quick automatic processing skills which are considered to be mediated by the caudate nucleus. We asked whether continued practice or rehearsal of the skill over a long period of time can lead to structural changes in this region. We found that, comparing to novice controls, grandmaster and master level Chinese chess players (GM/Ms), who had a mean period of over 10years of tournament and training practice, exhibited significant smaller gray-matter volume in the bilateral caudate nuclei. When these regions were used as seeds in functional connectivity analysis in resting-state fMRI, significantly enhanced integration was found in GM/Ms between the caudate and the default mode network (DMN), a constellation of brain areas important for goal-directed cognitive performance and theory of mind. These findings demonstrate the structural changes in the caudate nucleus in response to its extensive engagement in chess problem solving, and its enhanced functional integration with widely distributed circuitry to better support high-level cognitive control of behavior.
NeuroImage 01/2012; 60(2):1280-6. · 5.89 Impact Factor
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ABSTRACT: Cognitive performance relies on the coordination of large-scale networks of brain regions that are not only temporally correlated during different tasks, but also networks that show highly correlated spontaneous activity during a task-free state. Both task-related and task-free network activity has been associated with individual differences in cognitive performance. Therefore, we aimed to examine the influence of cognitive expertise on four networks associated with cognitive task performance: the default mode network (DMN) and three other cognitive networks (central-executive network, dorsal attention network, and salience network). During fMRI scanning, fifteen grandmaster and master level Chinese chess players (GM/M) and fifteen novice players carried out a Chinese chess task and a task-free resting state. Modulations of network activity during task were assessed, as well as resting-state functional connectivity of those networks. Relative to novices, GM/Ms showed a broader task-induced deactivation of DMN in the chess problem-solving task, and intrinsic functional connectivity of DMN was increased with a connectivity pattern associated with the caudate nucleus in GM/Ms. The three other cognitive networks did not exhibit any difference in task-evoked activation or intrinsic functional connectivity between the two groups. These findings demonstrate the effect of long-term learning and practice in cognitive expertise on large-scale brain networks, suggesting the important role of DMN deactivation in expert performance and enhanced functional integration of spontaneous activity within widely distributed DMN-caudate circuitry, which might better support high-level cognitive control of behavior.
PLoS ONE 01/2012; 7(3):e32532. · 4.09 Impact Factor
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Luqing Wei, Xujun Duan,
Yang Yang,
Wei Liao,
Qing Gao,
Ju-rong Ding,
Zhiqiang Zhang,
Weixi Zeng,
Yuan Li,
Guangming Lu,
Huafu Chen
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ABSTRACT: There is an increasing body of evidence pointing to a relationship between personality and brain markers. The purpose of this study was to identify the associations between personality dimensions of extraversion and neuroticism and the local synchronization of spontaneous blood oxygen level-dependent (BOLD) activity assessed by regional homogeneity (ReHo) approach. Our results revealed the significant negative correlation between neuroticism and ReHo in the left middle frontal gyrus, providing evidence for the left frontal activation involved in pleasant emotion. ReHo was correlated negatively with extraversion in the medial prefrontal cortex (MPFC), an important portion of the default mode network (DMN), thus further indicating the relationship between DMN and personality. In addition, ReHo in the insula, cerebellum and cingulate gyrus was correlated positively with extraversion, suggesting the associations between individual difference in extraversion and specific brain regions involved in affective processing. These findings shed light on the important relationship between the synchronization of spontaneous fluctuations and personality dimensions of extraversion and neuroticism, which provide further evidence for the neural underpinning of individual difference in personality traits.
Brain research 08/2011; 1419:68-75. · 2.46 Impact Factor
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ABSTRACT: Dysfunction of the corticolimbic circuitry has been highlighted in social anxiety disorder (SAD) during social stimuli. However, few studies have investigated functional connectivity in SAD during the resting state, which may improve our understanding of SAD pathophysiology. The aim of this study was to investigate whether whole-brain functional connectivity might be aberrant in SAD patients, and if so, whether these changes are related to the measured clinical severity. Seventeen SAD patients and 19 healthy controls participated in resting-state functional magnetic resonance imaging. The brain was first divided into 90 paired brain regions and functional connectivity was then estimated by temporal correlation between each of these regions. Furthermore, connections that were significantly disrupted in SAD patients were correlated with clinical severity measured using the Liebowitz Social Anxiety Scale. Compared with healthy controls, SAD patients showed decreased positive connections within the frontal lobe and decreased negative connections between the frontal and occipital lobes. In particular, the weaker negative connections between the frontal lobe, which mainly involved the right median prefrontal cortex, and the occipital lobe had a significant positive correlation with the severity of SAD symptoms. The results support the hypothesis that some abnormalities of functional connectivity exist in SAD patients, which relate to the frontal cortex and occipital cortex. In addition, decreased functional connectivity between the frontal and occipital lobes and within the frontal lobe might be related to abnormal information processing and reflect disturbed neural organization resulting in defective social cognition, which could represent an early imaging biomarker for SAD.
Magnetic Resonance Imaging 06/2011; 29(5):701-11. · 1.99 Impact Factor
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Wei Liao,
Zhiqiang Zhang,
Zhengyong Pan,
Dante Mantini,
Jurong Ding, Xujun Duan,
Cheng Luo,
Zhengge Wang,
Qifu Tan,
Guangming Lu,
Huafu Chen
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ABSTRACT: Studies of in mesial temporal lobe epilepsy (mTLE) patients with hippocampal sclerosis (HS) have reported reductions in both functional and structural connectivity between hippocampal structures and adjacent brain regions. However, little is known about the connectivity among the default mode network (DMN) in mTLE. Here, we hypothesized that both functional and structural connectivity within the DMN were disturbed in mTLE. To test this hypothesis, functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) were applied to examine the DMN connectivity of 20 mTLE patients, and 20 gender- and age-matched healthy controls. Combining these two techniques, we explored the changes in functional (temporal correlation coefficient derived from fMRI) and structural (path length and connection density derived from DTI tractography) connectivity of the DMN. Compared to the controls, we found that both functional and structural connectivity were significantly decreased between the posterior cingulate cortex (PCC)/precuneus (PCUN) and bilateral mesial temporal lobes (mTLs) in patients. No significant between-group difference was found between the PCC/PCUN and medial prefrontal cortex (mPFC). In addition, functional connectivity was found to be correlated with structural connectivity in two pairwise regions, namely between the PCC/PCUN and bilateral mTLs, respectively. Our results suggest that the decreased functional connectivity within the DMN in mTLE may be a consequence of the decreased connection density underpinning the degeneration of structural connectivity.
Human Brain Mapping 06/2011; 32(6):883-95. · 5.88 Impact Factor
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ABSTRACT: Canonical-correlation analysis as a multivariate statistical technique has been applied to multivariate Granger causality analysis to infer information flow in complex systems. It shows unique appeal and great superiority over the traditional vector autoregressive method, due to the simplified procedure that detects causal interaction between multiple time series, and the avoidance of potential model estimation problems. However, it is limited to the linear case. Here, we extend the framework of canonical correlation to include the estimation of multivariate nonlinear Granger causality for drawing inference about directed interaction. Its feasibility and effectiveness are verified on simulated data.
Physical Review E 04/2011; 83(4 Pt 1):041921. · 2.26 Impact Factor
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ABSTRACT: The effective connectivity networks among overlapped core regions recruited by motor execution (ME) and motor imagery (MI) were explored by means of conditional Granger causality and graph-theoretic method, based on functional magnetic resonance imaging (fMRI) data. Our results demonstrated more circuits of effective connectivity among the selected seed regions during right-hand performance than during left-hand performance, implying the influences of brain asymmetry of right-handedness on effective connectivity networks. The increased causal connections were found during ME than during MI, suggesting that the ME network may have some additional connections compared to MI networks to execute the overt physical movement. Furthermore, the In-Out degrees of information flow suggested left dorsal premotor cortex (PMd), inferior parietal lobule (IPL) and superior parietal lobule (SPL) as causal sources in ME/MI tasks, highlighting the dominant function of left PMd, IPL and SPL. These findings depicted the causal connectivity of motor related core regions in fronto-parietal circuit and might indicate the conversion of causal networks between ME and MI.
NeuroImage 01/2011; 54(2):1280-8. · 5.89 Impact Factor
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Wei Liao,
Huafu Chen,
Yuan Feng,
Dante Mantini,
Claudio Gentili,
Zhengyong Pan,
Jurong Ding, Xujun Duan,
Changjian Qiu,
Su Lui,
Qiyong Gong,
Wei Zhang
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ABSTRACT: Several functional MRI (fMRI) activation studies have highlighted specific differences in brain response in social anxiety disorder (SAD) patients. Little is known, so far, about the changes in the functional architecture of resting state networks (RSNs) in SAD during resting state. We investigated statistical differences in RSNs on 20 SAD and 20 controls using independent component analysis. A diffuse impact on widely distributed RSNs and selective changes of RSN intrinsic functional connectivity were observed in SAD. Functional connectivity was decreased in the somato-motor (primary and motor cortices) and visual (primary visual cortex) networks, increased in a network including medial prefrontal cortex which is thought to be involved in self-referential processes, and increased or decreased in the default mode network (posterior cingulate cortex/precuneus, bilateral inferior parietal gyrus, angular gyrus, middle temporal gyrus, and superior and medial frontal gyrus) which has been suggested to be involved in episodic memory, and self-projection, the dorsal attention network (middle and superior occipital gyrus, inferior and superior parietal gyrus, and middle and superior frontal gyrus) which is thought to mediate goal-directed top-down processing, the core network (insula-cingulate cortices) which is associated with task control function, and the central-executive network (fronto-parietal cortices). A relationship between functional connectivity and disease severity was found in specific regions of RSNs, including medial and lateral prefrontal cortex, as well as parietal and occipital regions. Our results might supply a novel way to look into neuro-pathophysiological mechanisms in SAD patients.
NeuroImage 10/2010; 52(4):1549-58. · 5.89 Impact Factor
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ABSTRACT: Previous functional neuroimaging studies have uncovered partly separable neural substrates for perceiving different facial expressions presented below the level of conscious awareness. However, as one of the six basic emotions, the neural mechanism of unconsciously perceiving surprised faces has not yet been investigated. Using a backward masking procedure, we studied the neural activities in response to surprised faces presented below the threshold of conscious visual perception by means of functional magnetic resonance imaging (fMRI). Eighteen healthy adults were scanned while viewing surprised faces, which presented for 33 ms and immediately "masked" by a neutral face for 467 ms. As a control, they viewed masked happy or neutral faces as well. In comparison to both control conditions, masked surprised faces yielded significantly greater activation in the parahippocampal gyrus and fusiform gyrus, which associated previously with novelty detection. In the present study, automatic activation of these areas to masked surprised faces was investigated as a function of individual differences in the ability of identifying and differentiating one's emotions, as assessed by the 20-item Toronto Alexithymia Scale (TAS-20). The correlation results showed that, the subscale, Difficulty Identifying Feelings, was negatively correlated with the neural response of these areas to masked surprised faces, which suggest that decreased activation magnitude in specific brain regions may reflect increased difficulties in recognizing one's emotions in everyday life. Additionally, we confirmed activation of the right amygdala and right thalamus to the masked surprised faces, which was previously proved to be involved in the unconscious emotional perception system.
NeuroImage 08/2010; 52(1):401-7. · 5.89 Impact Factor
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ABSTRACT: The functional architecture of the human brain has been extensively described in terms of functional connectivity networks, detected from the low-frequency coherent neuronal fluctuations that can be observed in a resting state condition. Little is known, so far, about the changes in functional connectivity and in the topological properties of functional networks, associated with different brain diseases.
In this study, we investigated alterations related to mesial temporal lobe epilepsy (mTLE), using resting state functional magnetic resonance imaging on 18 mTLE patients and 27 healthy controls. Functional connectivity among 90 cortical and subcortical regions was measured by temporal correlation. The related values were analyzed to construct a set of undirected graphs. Compared to controls, mTLE patients showed significantly increased connectivity within the medial temporal lobes, but also significantly decreased connectivity within the frontal and parietal lobes, and between frontal and parietal lobes. Our findings demonstrated that a large number of areas in the default-mode network of mTLE patients showed a significantly decreased number of connections to other regions. Furthermore, we observed altered small-world properties in patients, along with smaller degree of connectivity, increased n-to-1 connectivity, smaller absolute clustering coefficients and shorter absolute path length.
We suggest that the mTLE alterations observed in functional connectivity and topological properties may be used to define tentative disease markers.
PLoS ONE 01/2010; 5(1):e8525. · 4.09 Impact Factor
