Focal right temporo-occipital blood flow changes associated with judgment of line orientation.

Focal cerebral blood flow changes for judgment of line orientation were determined using the 133Xe inhalation technique with 18 normal right-handed male subjects. Measurements were made during three conditions in the same session: a line orientation task, a sensorimotor control task, and normal rest. Blood flow changes attributable to the judgment of line orientation were found for the measure f1 at a detector centered over the right temporo-occipital region. For the measure IS this activation was significant in the temporo-occipital region in both hemispheres but significantly greater in the right hemisphere. For f1 the change in blood flow and for IS the percent change in blood flow in the right temporo-occipital region attributable to judgment of line orientation decreased as performance on the line orientation task improved.

Measurement of activated rCBF by the 133Xe inhalation technique: a comparison of total versus partial curve analysis.

An initial assessment of the differential sensitivity of total versus partial curve analysis in estimating task related focal changes in cortical blood flow measured by the 133Xe inhalation technique was accomplished by comparing the patterns during the performance of two sensorimotor tasks by normal subjects. The validity of these patterns was evaluated by comparing them to the activation patterns expected from activation studies with the intra-arterial technique and the patterns expected from neuropsychological research literature. Subjects were 10 young adult nonsmoking healthy male volunteers. They were administered two tasks having identical sensory and cognitive components but different response requirements (oral versus manual). The regional activation patterns produced by the tasks varied with the method of curve analysis. The activation produced by the two tasks was very similar to that predicted from the research literature only for total curve analysis. To the extent that the predictions are correct, these data suggest that the 133Xe inhalation technique is more sensitive to regional flow changes when flow parameters are estimated from the total head curve. The utility of the total head curve analysis will be strengthened if similar sensitivity is demonstrated in future studies assessing normal subjects and patients with neurological and psychiatric disorders.

Benign familial chorea: an association with intellectual impairment.

Twenty-four members of a family with benign familial chorea underwent testing for evidence of intellectual impairment. Lower verbal intelligence was found in affected individuals compared to unaffected family members, as were deficits in verbal abstract concept formation. These results challenge the notion that benign familial chorea uniformly spares the intellect in all kindreds.

Relevance of sensorimotor task components to the interpretation of task related blood flow changes.

This study demonstrated the importance of documenting rCBF changes produced by the sensorimotor components of a cognitive task when making inferences regarding brain-behavior relations. Subjects were ten young, non-smoking adult, right-handed, normal male volunteers. They were administered two tasks having identical cognitive and similar sensory components but different response modalities (oral vs manual). The two tasks produced highly divergent rCBF landscapes. In conjunction with the results from a previous rCBF activation study, these data were used to illustrate the necessity of including sensorimotor control tasks in cognitive activation studies designed to elucidate brain-behavior relations.

rCBF for middle-aged males and females during right-left discrimination.

rCBF was measured in 10 male and 10 female normal righthanders with an average age of 44.2 years. For the measures f1 and IS significant occipital lobe activation was produced bilaterally and for the measure IS significant left hemisphere parietal activation was produced also by a visually presented right-left discrimination cognitive activation task over and above the activation produced by a sensorimotor control task. The amount and pattern of blood flow changes were similar for both sexes. Performance of males on the cognitive task was not significantly better than that of females. However, an inverse relationship was found for males but not females between cognitive task performance and percentage increase in IS for all regions showing significant cognitive activation.

Late-onset variant of Huntington's chorea.

We identified a large Georgia kinship in which a hereditary autosomal dominant chorea appeared at an average age of 65 years, much later than usual for Huntington's chorea. Progression was slow. Dementia was not an obvious initial feature. Family members denied that affected persons became demented, and those affected cognitively intact with bedside testing. However, deficits of memory were apparent on formal psychologic testing. In the propositus' generation, five of 12 siblings were affected during their 60s. Of 23 persons in a younger generation, aged 30 to 60 years, none was yet affected. A number of variants of Huntington's chorea have been proposed. In elderly patients without obvious dementia, psychologic testing may be of diagnostic importance, revealing characteristic memory deficits. When the disorder consistently occurs at an advanced age and progresses slowly, the implications for the family may be less grave than with Huntington's chorea of earlier onset.

Age effects on focal cerebral blood flow changes produced by a test of right-left discrimination.

The effects of age on focal cerebral blood flow changes resulting from the cognitive processing during right-left discrimination were examined. The pattern and amount of cortical flow were comparable for young and middle-aged subjects and consisted of flow increases in bilateral frontal, parietal and occipital regions. Task performance was negatively related to activation from left parietal and occipital channels. The frontal activation and the parietal correlation were attributed to the middle-aged subjects experiencing increased emotional arousal and attention to the right-left discrimination task due to hypothesized differences in cognitive effort and style, and/or novelty of formal examination situations.

Focal changes in cerebral blood flow produced by a test of right-left discrimination.

A sensorimotor control activation task was used to isolate the focal cerebral blood flow changes resulting from the visual and cognitive processing of a right-left discrimination task. Eleven normal right-handed males participated. The sensorimotor control task produced significant bilateral increases in flow in most cortical channels. Significant bilateral parieto-occipital activation was found for the right-left discrimination task over and above the flow changes produced by the sensorimotor control task. The left occipital flow increase resulting from the right-left discrimination task was found to be negatively related to task performance. An inverse relationship was also found between WAIS Performance IQ and the blood flow change in the left parietal channel. These results suggest areas for further testing concerning potential individual differences in cognitive processing during the performance of a right-left discrimination task.

A Yudin-type short form of the WISC-R: two aspects of validation.

Provided validity data for a Yudin-type short form of the WISC-R for N equal to 70 middle-class children (34 males and 36 females, X age equal to 7.6 years, SD equal to 2.58 months) of above-average intelligence (means: VIQ equal to 115.55, PIQ equal to 122.27, FIQ equal to 121.02). Short- to long-form validity coefficients were all above .90 for Verbal, Performance, and Full Scale IQ scores. Highly similar predictive validity coefficients were found for the short and long forms of the WISC-R when compared with the Metropolitan Achievement and Otis Lennon Mental Ability tests. In contrast, little support was found for the validity of the short-form profile data as assessed by Cattell's rp coefficient of profile similarity.

Chromatic specificity of the visual evoked response.

The temporal alternation of red and green stripes in a structured field produces successive contrast, which can elicit cortical potentials recorded from the scalp. Amplitudes of the major frequency components of the potentials correspond to the relative intensities of red and green producing the contrast. The amplitude variations are color-specific, since total luminance and structure are held constant.