Functional Magnetic Resonance Imaging Detects Between-Group Differences in Neural Activation Among Men with Delayed Orgasm Compared with Normal Controls: Preliminary Report

Abstract The authors used functional magnetic resonance imaging (fMRI) to investigate neural activation during a semantic-classification/object-recognition task in 13 persons with Down syndrome and 12 typically developing control participants (age range = 12–26 years). A comparison between groups suggested atypical patterns of brain activation for the individuals with Down syndrome. Correlation analyses between an index of visual spatial ability and brain activation depicted a positive relationship between (a) this index and brain activation in regions of the occipital and parietal lobes for the typically developing individuals and (b) the middle and dorsal frontal gyri in the individuals with Down syndrome. These findings supported the authors' hypothesis that persons with Down syndrome demonstrate atypical neural activation compared with typically developing individuals matched for chronological age.

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Neural activation during imitation of movements presented from four different perspectives: A functional magnetic resonance imaging study

Neuroscience Letters ◽

10.1016/j.neulet.2011.08.016 ◽

2011 ◽

Vol 503 (2) ◽

pp. 100-104 ◽

Cited By ~ 14

Author(s):

Rui Watanabe ◽

Shu Watanabe ◽

Hironobu Kuruma ◽

Yoshiyuki Murakami ◽

Atsushi Seno ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Functional Magnetic Resonance Imaging ◽

Imaging Study ◽

Neural Activation ◽

Magnetic Resonance Imaging Study ◽

Functional Magnetic Resonance ◽

Resonance Imaging

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Changes in Cerebral Blood Flow and Cerebral Oxygen Metabolism during Neural Activation Measured by Positron Emission Tomography: Comparison with Blood Oxygenation Level-Dependent Contrast Measured by Functional Magnetic Resonance Imaging

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/sj.jcbfm.9600030 ◽

2005 ◽

Vol 25 (3) ◽

pp. 371-377 ◽

Cited By ~ 52

Author(s):

Hiroshi Ito ◽

Masanobu Ibaraki ◽

Iwao Kanno ◽

Hiroshi Fukuda ◽

Shuichi Miura

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Functional Magnetic Resonance Imaging ◽

Venous Blood ◽

Blood Oxygenation ◽

Neural Activation ◽

Precentral Gyrus ◽

Bold Signal ◽

Functional Magnetic Resonance ◽

Resonance Imaging

The discrepancy between the increases in cerebral blood flow (CBF) and CMRO2 during neural activation causes an increase in venous blood oxygenation and, therefore, a decrease in paramagnetic deoxyhemoglobin concentration in venous blood. This can be detected by functional magnetic resonance imaging (fMRI) as blood oxygenation level-dependent (BOLD) contrast. In the present study, changes in the cerebral oxygen extraction fraction (OEF) that corresponds to the ratio of CMRO2 to CBF, and in the BOLD signal during neural activation, were measured by both positron emission tomography (PET) and fMRI in the same human subjects. C15O, 15O2, and H215O PET studies were performed in each subject at rest (baseline) and during performance of a right-hand motor task. Functional magnetic resonance imaging studies were then performed to measure the BOLD signal under the two conditions. During performance of the motor task, a significant increase in CBF and a significant decrease in OEF were observed in the left precentral gyrus, left superior frontal gyrus, right precentral gyrus, right cingulate gyrus, and right cerebellum. A significant positive correlation was observed between changes in the CBF and the BOLD signal, and a significant negative correlation was observed between changes in the OEF and the BOLD signal. This supports the assumption on which BOLD contrast studies during neural activation are based.

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