Xin Di

Publications

• 7.18

  Impact points

  Phase or amplitude? The relationship between ongoing and evoked neural activity.

  Chencan Qian, Xin Di

  The Journal of neuroscience : the official journal of the Society for Neuroscience. 07/2011; 31(29):10425-6.

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• 2.82

  Impact points

  White matter reduction in patients with schizophrenia as revealed by voxel-based morphometry: An activation likelihood estimation meta-analysis.

  Xin Di, Raymond C K Chan, Qi-Yong Gong

  Progress in neuro-psychopharmacology & biological psychiatry. 10/2009;

  Schizophrenia is thought to be a mental disorder caused by the disconnection of brain regions. Cumulative evidence of white matter deficit in patients with schizophrenia has been reported using voxel-based morphometry (VBM), but these studies have not been quantitatively reviewed. In the study repor... [more] Schizophrenia is thought to be a mental disorder caused by the disconnection of brain regions. Cumulative evidence of white matter deficit in patients with schizophrenia has been reported using voxel-based morphometry (VBM), but these studies have not been quantitatively reviewed. In the study reported herein, we used activation likelihood estimation (ALE) analysis to quantitatively estimate focal white matter abnormalities in patients with schizophrenia. Seventeen studies that compared the white matter deficit of patients with schizophrenia and healthy controls were ascertained. The frontal white matter regions and internal capsule revealed consistent white matter reduction in patient groups relative to healthy controls, suggesting a clear focal white matter deficit in patients with schizophrenia. These results support the macro-circuit theory of white matter change in schizophrenia.

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• 7.47

  Impact points

  Brain Anatomical Abnormalities in High-Risk Individuals, First-Episode, and Chronic Schizophrenia: An Activation Likelihood Estimation Meta-analysis of Illness Progression.

  Raymond C K Chan, Xin Di, Grainne M McAlonan, Qi-Yong Gong

  Schizophrenia bulletin. 08/2009;

  Objective: The present study reviewed voxel-based morphometry (VBM) studies on high-risk individuals with schizophrenia, patients experiencing their first-episode schizophrenia (FES), and those with chronic schizophrenia. We predicted that gray matter abnormalities would show progressive changes, wi... [more] Objective: The present study reviewed voxel-based morphometry (VBM) studies on high-risk individuals with schizophrenia, patients experiencing their first-episode schizophrenia (FES), and those with chronic schizophrenia. We predicted that gray matter abnormalities would show progressive changes, with most extensive abnormalities in the chronic group relative to FES and least in the high-risk group. Method: Forty-one VBM studies were reviewed. Eight high-risk studies, 14 FES studies, and 19 chronic studies were analyzed using anatomical likelihood estimation meta-analysis. Results: Less gray matter in the high-risk group relative to controls was observed in anterior cingulate regions, left amygdala, and right insula. Lower gray matter volumes in FES compared with controls were also found in the anterior cingulate and right insula but not the amygdala. Lower gray matter volumes in the chronic group were most extensive, incorporating similar regions to those found in FES and high-risk groups but extending to superior temporal gyri, thalamus, posterior cingulate, and parahippocampal gryus. Subtraction analysis revealed less frontotemporal, striatal, and cerebellar gray matter in FES than the high-risk group; the high-risk group had less gray matter in left subcallosal gyrus, left amygdala, and left inferior frontal gyrus compared with FES. Subtraction analysis confirmed lower gray matter volumes through ventral-dorsal anterior cingulate, right insula, left amygdala and thalamus in chronic schizophrenia relative to FES. Conclusions: Frontotemporal brain structural abnormalities are evident in nonpsychotic individuals at high risk of developing schizophrenia. The present meta-analysis indicates that these gray matter abnormalities become more extensive through first-episode and chronic illness. Thus, schizophrenia appears to be a progressive cortico-striato-thalamic loop disorder.

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• 7.39

  Impact points

  Dexterous movement complexity and cerebellar activation: A meta-analysis.

  Raymond C K Chan, Jia Huang, Xin Di

  Brain research reviews. 11/2008;

  The importance of the cerebellum in coordinates of movement has been established by lesion studies. However, there is no clear understanding of whether there is consistent activation in cerebellum across various motor task complexities or how different parts of the cerebellum contribute to finger co... [more] The importance of the cerebellum in coordinates of movement has been established by lesion studies. However, there is no clear understanding of whether there is consistent activation in cerebellum across various motor task complexities or how different parts of the cerebellum contribute to finger coordinates in dexterous manipulation. This article reviews imaging studies with data from healthy subjects. A mini meta-analysis using label-based and activation likelihood estimation (ALE) methods reveals that ipsilateral anterior and vermis regions of the cerebellum were consistently activated across various dexterous movement complexities and were associated with finger and hand movement.

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• 5.74

  Impact points

  A regulation role of the prefrontal cortex in the fist-edge-palm task: Evidence from functional connectivity analysis.

  Hengyi Rao, Xin Di, Raymond C K Chan, Yulong Ding, Binbin Ye, Dingguo Gao

  NeuroImage. 08/2008; 41(4):1345-1351.

  The Fist-Edge-Palm (FEP) task is a motor sequencing task that is widely used in neurological examination. Deficits in this task are believed to reflect impairment in the frontal lobe regions. However, two recent functional brain imaging studies of the FEP task using conventional subtraction analysis... [more] The Fist-Edge-Palm (FEP) task is a motor sequencing task that is widely used in neurological examination. Deficits in this task are believed to reflect impairment in the frontal lobe regions. However, two recent functional brain imaging studies of the FEP task using conventional subtraction analysis failed to demonstrate FEP-induced activation in the prefrontal cortex (PFC), which contradicts existing neuropsychological literature. In this study, psychophysiological interaction (PPI) analysis was used to reanalyze our previous neuroimaging dataset from 10 healthy subjects in order to evaluate the changes of functional connectivity between the sensorimotor cortex and the prefrontal regions during the performances of the FEP task relative to simple motor control tasks. The PPI analysis revealed significantly increased functional connectivity between bilateral sensorimotor cortex and the right inferior and middle frontal cortex during the performance of the FEP task compared with the control tasks. However, regional signal changes showed no significant activation differences in these prefrontal regions. These results provide evidence supporting the involvement of the frontal lobe in the performance of the FEP task, and suggest a role of regulation, rather than direct participation, of the prefrontal cortex in the execution of complex motor sequence tasks such as the FEP task.

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• Progress in functional connectivity analysis

  X. Di, H. Rao

  Progress in Biochemistry and Biophysics. 01/2007; 34(1):5.

• Calibrating BOLD fMRI Activations with Neurovascular and Anatomical Constraints

  X Di, S S Kannurpatti, B Rypma, B B Biswal

  Cerebral Cortex.

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