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Biomedical subjects

H W Gordon

Publications and source records attributed to H W Gordon.

At least 37 records · Page 2Linked to original sources

Selective language deterioration in chronic schizophrenia.

Chronic schizophrenics as a group were inferior to controls on tests of neuropsychological function. When divided into groups according to length of illness they differed from each other primarily in tests of language. No other deficits in cognitive function progressed; the performance of the patients on memory, visuo-spatial tasks, rate of information processing and abstract thinking did not decline according to length of illness. The results indicate that chronic schizophrenia is characterised by a selective deterioration of language, which correlates with the notion that schizophrenia may be associated with left hemisphere dysfunction.

Adult↗

Degree of ear asymmetries for perception of dichotic chords and for illusory chord localization in musicians of different levels of competence.

Left-ear superiority for perception of dichotically presented musical chords was seen in musicians at all levels of competence. However, a hypothesis that dominance would be greater in the more professional musicians was not confirmed. Whereas many of the professionals did have the largest left-ear preferences, about half had strong right-ear superiorities instead. On the average, therefore, there was no ear dominance for the two most professional groups, although the other groups had the expected left-ear dominance. Furthermore, ear differences for the professional groups were distributed only in the categories of weak to strong left- and weak to strong right-ear preferences, whereas ear differences for the other groups included also the central categories of no or little ear preference. The better musician groups were also more strongly affected by an auditory illusion in which right-ear dominance occurred when subjects reported the ear receiving the high chord, whereas left-ear dominance was seen when they reported the ear receiving the low chord (for the same dichotic pair). That is, ear dominance was dependent on instructions, switching in the same subject from left to right ear when the task changed from reporting the location of the low to reporting the location of the high chord, respectively. However, ear dominance and switching were only partially present in nonmusicians and were weak in amateurs. It may be that ear dominance for chord recognition is influenced by specialized cognitive development in musicians, on the one hand, and by noncognitive neurophysiological factors on the other.

Adolescent↗

Assessment of cognitive asymmetries in brain-damaged and normal subjects: validation of a test battery.

A test battery designed to assess cognitive functions normally related to the left and right cerebral hemispheres was validated on 30 patients with unilateral (16 right, 14 left) lesions. The tests were preselected to reflect typical functioning of the hemispheres according to general agreement in the literature. A Cognitive Laterality Quotient (CLQ) was calculated from the difference in performance between the "right" and "left" test batteries and, therefore, reflected the relative functioning attributed to the right and left hemispheres. Using the CLQ measurement and a control group of 30 non-neurological patients matched for age and education, 28 out of 30 brain-damaged patients (93%) were categorised correctly according to side of lesion; the other two were considered to have either abnormal lateralisation (one was left handed) or asymmetrical premorbid cognitive profiles. Using only one (paired) test whose two subparts were designed to vary only slightly in task requirements to measure either right or left functioning, 29 out of 30 patients were correctly categorised. It is suggested that the concept of relative assessment of basic cognitive functions is more fruitful than general assessment of intellectual functions for use in diagnosis and rehabilitation of neurological patients or normal subjects with developmental or acquired behavioural cognitive abnormalities.

Adult↗

Differential aphasia in tow bilingual individuals.

Moderate nonfluent aphasia following a left parietotemporal lesion was found in the native language of one bilingual patient, in contrast to less severe, fluent aphasia in the patient's secondary language. Conversely, mild anomia was found in the native language of a second patient, while global aphasia was found in the secondary language. His lesion was located in the left posterior frontal area. These examples of differential aphasia were assessed by standard aphasia tests and by language inventory translated into the appropriate languages. We propose that differential aphasia resulting from a single hemispheric lesion is related to the disruption of different basic cognitive functions, which participate to varying degrees in the performance of the languages affected. In terms of neurolinguistic theory, the findings in these patients support the observation that most frequently used language is the first to recover. They refute the notion that the native language recovers first.

Adult↗

Left hemisphere dominance for rhythmic elements in dichotically-presented melodies.

Right ear superiority was found for two groups of 24 subjects on a dichotic listening test of melodies each differing only in rhythm. In addition, no ear difference was found in the same two groups for a dichotic melodies test differing only in pitch or pitch pattern. Finally, the usual left ear superiority was seen for dichotic presentation of chords and the usual right ear superiority was seen for the dichotic presentation of digits. The results imply that in neither of the non-verbal (melodies) tests was the right hemisphere superior to the left. In fact for one test the reverse was true: the left hemisphere was superior to the right for melody recognition based on a rhythm cue. The apparent conflict between this and previous studies is explained by the notion that it is not the stimuli per se that govern hemispheric dominance, but rather the cognitive functioning required by the left and right hemispheres in order to process them.

Adolescent↗

Retraining in literal alexia: substitution of a right hemisphere perceptual strategy for impaired left hemispheric processing.

An adult patient with literal alexia, agraphia, slight anomia, and dyscalculia due to a left hemisphere infarct showed lack of sequential skills while pattern recognition remained intact. Some words were recognized as patterns, but could not be read phonetically. Therapy concentrated on forming an association of the visual pattern of the complete word with the retained auditory pattern. In this way the patient learned to read several hundred words and short phrases, even as anomia worsened. The patterns learned could not be generalized to noun declension or verb conjugation, or broken into smaller words. This learning process is characteristic of right hemispheric skills which were utilized as left hemispheric functions deteriorated.

Agraphia↗

Hemispheric lateralization of singing after intracarotid sodium amylobarbitone.

Hemispheric lateralization of singing was investigated in patients who had transient hemiplegia after intracarotid injection of sodium amylobarbitone. It was found that after right carotid injection singing was markedly deficient, whereas speech remained relatively intact. Songs were sung in a monotone, devoid of correct pitch rendering; rhythm was much less affected. By contrast, singing was less disturbed than speech after left carotid injection. The observations indicated a double dissociation; the right hemisphere contributed more for singing, whereas the left demonstrated its usual dominance for speech. A model is proposed that encompasses audible stimuli as well as tactual or visual into a scheme of functional lateralization wherein the right hemisphere specializes in processing a complete, time-independent stimulus configuration and the left in a series of successive, time-dependent units.

Adult↗