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Cross-modal binding in auditory-visual speech perception was investigated by using the McGurk effect, a phenomenon in which hearing is altered by incongruent visual mouth movements. We used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). In each experiment, the subjects were asked to identify spoken syllables ('ba',(More)
OBJECTIVE A fully automatic multimodality image registration algorithm is presented. The method is primarily designed for 3D registration of MR and PET images of the brain. However, it has also been successfully applied to CT-PET, MR-CT, and MR-SPECT registrations. MATERIALS AND METHODS The head contour is detected on the MR image using a gradient(More)
Modern functional neuroimaging methods, such as positron-emission tomography (PET), optical imaging of intrinsic signals, and functional MRI (fMRI) utilize activity-dependent hemodynamic changes to obtain indirect maps of the evoked electrical activity in the brain. Whereas PET and flow-sensitive MRI map cerebral blood flow (CBF) changes, optical imaging(More)
1. Several areas in the monkey dorsal visual pathway, including the dorsal part of the medial superior temporal area, have been found to contain cells responding to movements of a wide visual field and are suggested to be involved in analyzing self-induced motion information. In the present study, positron emission tomography was used to localize human(More)
Hypercapnia induces cerebral vasodilation and increases cerebral blood flow (CBF), and hypocapnia induces cerebral vasoconstriction and decreases CBF. The relation between changes in CBF and cerebral blood volume (CBV) during hypercapnia and hypocapnia in humans, however, is not clear. Both CBF and CBV were measured at rest and during hypercapnia and(More)
The hemodynamic mechanism of increase in cerebral blood flow (CBF) during neural activation has not been elucidated in humans. In the current study, changes in both regional CBF and cerebral blood volume (CBV) during visual stimulation in humans were investigated. Cerebral blood flow and CBV were measured by positron emission tomography using H(2)(15)O and(More)
The authors examined 50 patients with cerebral glioma with use of positron emission tomography (PET) and L-[methyl]-[11C]methionine to assess the grade of malignancy and the extent of cerebral glioma. Carbon-11 methionine was highly accumulated in the lesion in 31 of 32 patients with high-grade glioma and 11 of 18 patients with low-grade glioma. The rate of(More)
To investigate changes in cerebral circulation and oxygen metabolism during aging, regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rOEF), regional cerebral metabolic rate of oxygen (rCMRO2) and regional cerebral blood volume (rCBV) were measured using the 15O labelled gas inhalation technique and a multi-slice positron emission(More)
We investigated the relationship between evoked local cerebral blood flow (LCBF) and the field potential induced by somatosensory activation. The specific aim of the present study was to examine the correlation between variations of evoked LCBF and field potential when the stimulus duration was changed, and the dependency of the correlation on stimulus(More)
In many studies on functional neuroimaging, change in local cerebral blood flow induced by sensory stimulation (evoked LCBF) is used as a marker for change in cortical neuronal activity, although a full description of the relationship between the evoked LCBF and neuronal activity has not been given. The purpose of this study was to estimate the close(More)