1. Regional cerebral blood flow (rCBF) was measured using positron emission tomography in six normal volunteers while at rest and performing four different repetitive movements of the right arm. 2. The were performed random order consisted abduction index finger, making a fist, sequential thumb to digit opposition, shoulder flexion. All done same rate, an auditory cue involved displacements through similar amounts physiological range each joint. 3. Increases rCBF interpreted as evidence...

1. Using positron emission tomography and measurement of regional cerebral blood flow (rCBF) as an index activity we investigated the central processing motor preparation in 13 healthy volunteers. 2. We used a reaction time paradigm with visual cues preparatory response signals. A stimulus (PS) provided either full, partial, or no information regarding two variables forthcoming right finger movement: type (index little finger) movement direction (abduction elevation). After variable delay...

Mesial motor areas in self-initiated versus externally triggered movements examined with fMRI: effect of movement type and rate. The human frontomesial cortex reportedly contains at least four cortical that are involved control: the anterior supplementary area (pre-SMA), posterior SMA (SMA proper, or SMA), and, cingulate cortex, rostral zone (RCZ) caudal (CCZ). We used functional magnetic resonance imaging (fMRI) to examine role each these mesial visually movements. Healthy subjects...

Brain regions activated with complex sequential finger movements were localized by measuring regional cerebral blood flow (rCBF) positron emission tomography. Whereas the total number and frequency of kept constant, complexity auditory cued right hand varied, sequence length as independent variable. In four conditions differing complexity, bilateral primary sensorimotor area, left ventral premotor cortex, posterior supplementary motor superior part cerebellum, putamen consistently equally...

The clinical, electrophysiological and haemodynamic effects of precentral gyrus stimulation (PGS) as a treatment refractory post-stroke pain were studied in 2 patients. first patient had right hemibody secondary to left parietal infarct sparing the thalamus, while second lower limb developed after mesencephalic infarct. In both cases, spontaneous was associated with hyperpathia, allodynia hypoaesthesia painful territory involving lemniscal extra-lemniscal sensory modalities 1, modality only...

Working memory involves the short-term storage and manipulation of information necessary for cognitive performance, including comprehension, learning, reasoning planning. Although electroencephalogram (EEG) rhythms are modulated during working memory, temporal relationship EEG oscillations with eliciting event has not been well studied. In particular, dynamics neural network supporting processes may be best captured in induced oscillations, characterized by a loose link stimulus. order to...

To study the effect of repetition rate a simple movement on distribution and magnitude neuronal recruitment, we measured regional CBF (rCBF) in eight normal volunteers, using positron emission tomography 15O-labeled water. An auditory-cued, repetitive flexion right index finger against thumb was performed at very slow (0.25 0.5 Hz), (0.75 1 fast (2 2.5 (3 4 Hz) rates. The increase rCBF during relative to resting condition calculated for each pair conditions. Left primary sensorimotor cortex...

Deiber, M.-P., S. P. Wise, M. Honda, J. Catalan, Grafman, and Hallett. Frontal parietal networks for conditional motor learning: a positron emission tomography study. Neurophysiol. 78: 977–991, 1997. Studies on nonhuman primates show that the premotor (PM) prefrontal (PF) areas are necessary arbitrary mapping of set stimuli onto responses. However, (PET) measurements regional cerebral blood flow (rCBF) in human subjects have failed to reveal predicted rCBF changes during such behavior. We...

<b><i>Objective:</i></b> To study regional cerebral blood flow (rCBF) in patients with simple writer’s cramp using PET to identify regions that malfunction. <b><i>Background:</i></b> Several lines of evidence indicate impaired cortical function focal dystonia, but the precise pathophysiology is still unknown. <b><i>Methods:</i></b> Seven were compared seven age- and sex-matched control subjects. Control subjects scanned during sustained contraction, tapping, writing right hand. After...

Parkinsonian tremor can be abolished by chronic high frequency thalamic stimulation of the ventral intermediate nucleus. We have studied six patients with unilateral Parkinson's disease. The had an electrode chronically implanted in nucleus thalamus. measured changes cerebral activity positron emission tomography using index regional blood flow (rCBF). Each patient was scanned three states: (i) without (condition A); (ii) ineffective B); (iii) effective C). suppression (C compared B)...

Abnormal patterns of electrical oscillatory activity have been repeatedly described in adult ADHD. In particular, the alpha rhythm (8-12 Hz), known to be modulated during attention, has previously considered as candidate biomarker for present study, we asked ADHD patients self-regulate their own using neurofeedback (NFB), order examine modulation oscillations on attentional performance and brain plasticity. Twenty-five 22 healthy controls underwent a 64-channel EEG-recording at resting-state...

To evaluate the effect of repetition rate a simple movement on magnitude neuronal recruitment in primary sensorimotor cortex, we used blood flow-sensitive, echo planar functional magnetic resonance imaging (fMRI) sequence six normal volunteers. Three volunteers also had [ 15 O]water positron emission tomography (PET) studies using same paradigm. Previous PET shown an increase regional CBF (rCBF) with frequencies up to 2 Hz and then plateau cerebral flow at faster frequencies. extent...

A new method to measure regional CBF is presented, applying both dynamic and integral analyses a sequence of positron emission tomographic scans collected during following the administration H2(15)O (inhalation C15O2). The analysis used correct continuously monitored arterial whole-blood activity for delay dispersion relative tissue scans. An including corrections this then calculate on pixel-by-pixel basis. Normal values reproducibility over 2-h period are together with results validation...

Abstract Although motor performance may be enhanced through mental practice, the neurophysiological substrate of stimulation (ideation) a task is not well established. We used blood oxygen level‐dependent contrast echo planar imaging at 1.5 T to identify regions increased neural activity during and ideation task. Five subjects performed sequential finger‐to‐thumb opposition also imagined themselves performing in absence actual muscle movement. In all subjects, left primary sensorimotor...

Alpha-band activity (8-13 Hz) is not only suppressed by sensory stimulation and movements, but also modulated attention, working memory mental tasks, could be sensitive to higher motor control functions. The aim of the present study was examine alpha oscillatory during preparation simple left or right finger contrasting external internal mode action selection. Three conditions were examined using a precueing paradigm with S1 as preparatory S2 imperative cue: Full, laterality instructed S1;...