Biomedical subjects

Jiangxi Xiao

Publications and source records attributed to Jiangxi Xiao.

4 recordsLinked to original sources

PubMed2006

Handedness-related functional connectivity using low-frequency blood oxygenation level-dependent fluctuations.

Functional neuroimaging studies of handedness have traditionally focused on exploring regionally activated discrepancies, yet little is known regarding the effect of handedness on functional connections of brain regions. Here, we reported the relationship between cerebellar functional connectivity patterns and handedness by low-frequency blood oxygenation level-dependent fluctuations. Compared with the right-handers, the left-handers show higher cerebellar-prefrontal, cerebellar-parietal, and cerebellar-temporal functional connectivity, and lower cerebellar-limbic connectivity. Previous non-human primate studies have shown that these regions with known contributions to higher cognitive functions have afferent or efferent connections with the cerebellum. Our findings suggest that these observed low-frequency fluctuation correlations may reflect actually anatomic connections between the cerebellum and cerebral cortex, and the cerebellar involvement in higher function may be associated with handedness.

Adult↗

PubMed2005

Side and handedness effects on the cingulum from diffusion tensor imaging.

In order to explore the microstructure of bilateral cingulum bundles associated with side and handedness, fractional anisotropy was extracted from diffusion tensor imaging. Distinguished from the conventional region of interest-based method, a fiber-based analysis method called scale-invariant parameterization method was employed to ascertain the anisotropy along the cingulum bundle in 31 normal right-handers and 14 normal left-handers. The statistical results showed a remarkable left-greater-than-right asymmetry pattern of anisotropy in most segments of cingulum bundles except the most posterior segment, for both right-handers and left-handers. Interestingly, higher anisotropy of the right-hander than the left-hander was found in the bilateral cingulum bundles. No significant handedness-by-side interaction was obtained in the present study, however.

Adult↗

PubMed2005

Asymmetry analysis of cingulum based on scale-invariant parameterization by diffusion tensor imaging.

Current analysis of diffusion tensor imaging (DTI) is based mostly on a region of interest (ROI) in an image dataset, which is specified by users. This method is not always reliable, however, because of the uncertainty of manual specification. We introduce an improved fiber-based scheme rather than an ROI-based analysis to study in DTI datasets of 31 normal subjects the asymmetry of the cingulum, which is one of the most prominent white matter fiber tracts of the limbic system. The present method can automatically extract the quantitative anisotropy properties along the cingulum bundles from tractography. Moreover, statistical analysis was carried out after anatomic correspondence specific to the cingulum across subjects was established, rather than the traditional whole-brain registration. The main merit of our method compared to existing counterparts is that to find such anatomic correspondence in cingulum, a scale-invariant parameterization method by arc-angle was proposed. It can give a continuous and exact description on any segment of cingulum. More interestingly, a significant left-greater-than-right asymmetry pattern was obtained in most segments of cingulum bundle (-50-25 degrees), except in the most posterior portion of cingulum (25-50 degrees).

Adult↗

PubMed2003

[The fMRI study of the calculation tasks in normal aged volunteers].

OBJECTIVE: To investigate the feasibility and cortex activation of fMRI in aged volunteers during the performance of calculation tasks. METHODS: Internal mental calculation tasks including simple tasks and complicated tasks were conducted in 11 normal aged volunteers. The fMRI data was postprocessed using SPM99 to reveal the activated cortex. RESULTS: The simple calculation tasks were fulfilled satisfactorily in all aged subjects. Cortex in the bilateral Superior parietal lobule, inferior parietal lobule and bilateral occipital lobes showed activation. We found a selective enhancement of fMRI signal in Brodmann regions 9, 10 and 46 in the complicated tasks. CONCLUSION: fMRI tasks are feasible in aged people and more cortex of the left frontal lobe shows activation in complicated calculation tasks.

Aged↗