Biomedical subjects
R Zenhausern
Publications and source records attributed to R Zenhausern.
Continuous temporal evaluation of the effect of meprobamate on critical flicker frequency in normal subjects.
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The dual nature of lateral eye movements.
This study investigated the validity of lateral eye movements (LEM) as a measure of the individual differences and task demands aspects of LEM by comparing eye movements to information questions that had no clear hemispheric locus with eye movements to rhyme questions that demanded specific left hemisphere involvement. Fifty subjects were asked to respond to the two types of questions and the initial direction of their eye movement was recorded. The results indicated that LEM are a reliable measure of individual differences because both test-retest and split half reliabilities were high (.78 to .85). LEM were also shown to be responsive to task demands. The number of leftward LEM did not differ from rhyme and information questions, but there were more rightward LEM and fewer stares to the rhyme question. These results suggest that LEM are a reliable individual difference measure and are sensitive to task differences. There is clear evidence that LEM have neuropsychological implications, but every task demands the integrated functioning of the whole brain and these implications should not be overgeneralized.
Dichotic listening and the cerebral organization of the phonetic and semantic components of language.
Two words were presented dichoticly and the subject was required to point to visually presented words that either rhymed with or were semantically related to those words. Task demands were varied in terms of the number and type of stimuli which the auditory and visual words actually matched. Performance was superior when either type of stimulus was presented to the Left Hemisphere via the Right Ear, resulting in the standard Right Ear Advantage (REA) for verbal material. The strength of the REA, however, depended both on the type of stimuli and the specific demands of the task. It was concluded that, since language has many components, dichotic listening can be used to investigate the relative contributions of the two cerebral hemispheres to those various components.