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Biomedical subjects

R A Block

Publications and source records attributed to R A Block.

8 recordsLinked to original sources
PubMed1989

Unilateral nostril breathing influences lateralized cognitive performance.

Relative nostril efficiency (nasal cycle) is related to hemispheric EEG differences and performance on cognitive tasks. We investigated how unilateral forced nostril breathing influences spatial and verbal performance. Right-handed males and females performed both tasks under either left-nostril, right-nostril, or free-breathing conditions. Unilateral breathing affects performance differently in males and females. It influences male performance ipsilaterally on both tasks: Their spatial performance is better during right-nostril breathing, and their verbal performance is better during left-nostril breathing. Unilateral breathing influences female performance contralaterally, but only on the spatial task: Their spatial performance is better during left-nostril breathing. These differences within and between sexes may exist because unilateral nostril breathing differentially activates the two hemispheres and thereby facilitates performance, or because attempts of the brain to control the nasal cycle unilaterally interfere with performance.

Adult↗
PubMed1982

Temporal judgments and contextual change.

Three experiments investigated effects of environmental context on temporal memory judgments. An equal number of items occurred within each of two equal durations (D1 and D2). Subjects subsequently were asked to judge the length of a given duration in comparison with the other, then to discriminate the correct list and serial position for each recognized item on a test. If environmental context was unchanged, D1 was remembered as being longer than D2; if the context was disrupted during the interval separating D1 and D2, this effect was reduced; and if the context prevailing during D2 also was changed, the effect was eliminated. List discrimination was improved only if the context was changed. Serial-position judgment was not affected by either manipulation. Changes in process context--the internal context produced by the performance of specific cognitive processes--lengthened remembered duration, but the effect did not simply add on to the effects of environmental context. Results are discussed in terms of a contextual-change hypothesis.

Attention↗
PubMed1979

Aspiration of infected sarco-iliac joints.

Seven of eight patients with suspected sarco-iliac joint infection had the diagnosis confirmed by closed aspiration of the joint. A reproducible method of obtaining specimens for culture was developed. Failures of aspiration may occur in patients in whom anatomical variations cause segmentation of the joint, therefore preventing the septic process from involving the most posterior and caudal part.

Arthritis, Infectious↗