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Biomedical subjects

R C Gur

Publications and source records attributed to R C Gur.

160 records · Page 9Linked to original sources
PubMed1978

Emotions are expressed more intensely on the left side of the face.

Pictures of human faces posing six distinct emotions (plus a neutral expression) and their mirror reversals were split down the midlines, and left-side and right-side composites were constructed. Subjects judged left-side composites as expressing emotions more intensely than right-side composites. The finding indicates hemispheric asymmetry in the control over emotional expression in the face.

Emotions↗
PubMed1975

Visual imagery and the discrimination of differences between altered pictures simultaneously and successively presented.

Ten 'good' visual imagers and ten 'poor' imagers, representing the upper and lower halves of an unselected sample of adult volunteers, were given a task of detecting differences between altered pictures presented in pairs, either simultaneously or successively. Performance was measured by reaction time. 'Good' imagers reacted faster than 'poor' imagers, and the mode of presentation (simultaneous v. successive) did not affect their performances. 'Poor' imagers, on the other hand, reacted significantly slower when the pictures compared were presented successively. The results suggest that self-rated visual imagery can be used to predict the successful recall of visual information required in a discrimination task.

Adult↗
PubMedDate not supplied

Subcortical metabolic alterations in partial epilepsy.

The function of subcortical nuclei in partial epilepsy was investigated using positron emission tomography (PET) to measure metabolism in the basal ganglia and thalamus. Sixteen patients undergoing surgical evaluation were studied with 18F-fluorodeoxyglucose (FDG) interictally and had intensive extracranial and intracranial electrophysiologic evaluations. Eight patients had left temporal lobe seizure foci, six had right temporal lobe foci, and two had right posterotemporal or parietal foci. The PET data were analyzed visually and quantitatively, using a multivariate analysis of variance on the quantitative data. Hypometabolism of subcortical nuclei was present ipsilateral to the cortical seizure focus. Cortical hypometabolism was noted focally in the temporal lobe in patients with left temporal lobe seizure foci, whereas patients with right temporal lobe seizure foci had diffuse hemispheric hypometabolism. We postulate that the subcortical hypometabolism is secondary to decreased efferent activity from temporal lobe structures, in particular amygdala and hippocampus, to subcortical nuclei. Diminished subcortical activity may then lead to defective regulation of cortical excitability in the temporal lobe, increasing the likelihood of seizure development and spread.

Adult↗
PubMedDate not supplied

Regional cerebral blood flow in stroke: hemispheric effects of cognitive activity.

Regional cerebral blood flow (rCBF) was measured with the xenon-133 inhalation technique in 15 patients with unilateral cerebral infarction and 12 matched controls. Measurements were performed during a standard resting baseline condition and during the performance of standardized verbal analogies and spatial line orientation tasks. Resting and activated CBF were lower in patients than in controls, and there were differences in the hemispheric pattern of activated CBF. Control subjects replicated earlier findings of asymmetric increase in CBF for the cognitive tasks, whereas patients showed abnormalities in lateralized CBF changes consistent with side of infarction. These findings underscore the utility of cognitive challenges in the study of rCBF in stroke. This can lead to an experimental paradigm in clinical studies of the relation between behavioral deficits and regional brain dysfunction and may also improve the utility of CBF measurements in clinical settings.

Cerebrovascular Circulation↗