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E Zaidel

Publications and source records attributed to E Zaidel.

59 records · Page 4Linked to original sources
PubMed1976

Auditory vocabulary of the right hemisphere following brain bisection or hemidecortication.

Unilateral scores of two commissurotomy and three (one left and two right) hemispherectomy patients were obtained on standardized auditory language comprehension tests which use pointing responses to a pictorial array. Unilateral performance by the commissurotomy patients was achieved by restricting the pictorial array to one visual half field, using a novel contact lens system which permits ocular scanning of the lateralized stimulus and self-monitoring of task performance. Using the Peabody and Ammons Picture Vocabulary Tests, the auditory vocabulary in the disconnected or isolated right hemispheres was found to be equivalent to that of normal subjects of ages 8:1 to 16:3 with a mean of 11:7 (eleven years and 7 months old). At the same time, standardized aphasia tests showed that the picture vocabulary in the right hemispheres is similar to that of a heterogeneous population of aphasics, even though the right hemispheres did not behave quite like any classical aphasic diagnostic group. No significant differences were found between right hemisphere comprehension of object vs. action names. Results indicated that vocabulary as a function of word frequency followed the same pattern in the right and left hemisphere although the right hemisphere was consistently lower. This parallel between the two hemispheres was conjectured to reflect some similar or even shared lexical structures in the two hemispheres. Together with other data on the performance of the right hemisphere on the Token Test (Zaidel, 1976), the results suggest a complex model of the development of language laterality in the brain, in which some, but not all, auditory language functions continue to develop in the right hemisphere past what is generally regarded as the critical period for language acquistion. In general, auditory language comprehension is better characterized as that of an "average aphasic" than that of a child of a specific age.

Aphasia↗
PubMedDate not supplied

Bifurcation patterns in the human sylvian fissure: hemispheric and sex differences.

The sylvian fissure bifurcates posteriorly into ascending and descending rami. The diversity in the specific arrangement of these rami and in the length of a more anterior segment of the fissure, between the bifurcation point and Heschl's gyrus (segment H-B), was analyzed qualitatively and quantitatively, in both left and right hemispheres and in both males and females. Qualitatively, four basic patterns of bifurcation appeared: (A) the ascending ramus is larger than the descending one (61.25% of the cases). In half of these cases segment H-B was very short (designated as 'short H-B'). The other patterns were: (B) the descending ramus is larger than the ascending one (7.5% of the total); (C) both rami are of approximately equal size (10% of the cases); and (D) both are of approximately equal size but the ascending ramus is oriented frontally instead of caudally as in the other cases (21.25% of the cases). Type D has not been reported before, and may be considered a new variant of bifurcating rami that in many cases corresponds to what other authors have referred to as the absence of an ascending ramus. We found a biased distribution of the fissure types according to hemispheres and also sex, with type A being more common in males and in the right hemisphere, and type D more common in females and in the left hemisphere. When the two hemispheres of each subject were matched, no correspondence was observed between the fissurization pattern of one hemisphere and that of the other, indicating that fissurization develops independently in each hemisphere. Quantitative analyses confirmed these findings and showed some new relations between components of the sylvian fissure. For example, when pooling together all fissure types a negative correlation between segment H-B and the ascending ramus was observed in males but not in females. On average, segment H-B was larger on the left side while the ascending ramus was larger on the right, confirming previous reports. Since earlier studies indicate that the planum temporale is larger on the left side, we suggest that the latter usually corresponds to segment H-B. However, the 'short H-B' cases described above have an unusually long and deep ascending branch, indicating that the planum temporale may run into the latter in these cases. The present classification of fissure types therefore describes a new variant of fissurization patterns in the sylvian fissure, which is asymmetrically distributed across the hemispheres and is perhaps sexually dimorphic. Furthermore, our analysis of fissure morphology and asymmetry is of direct relevance to the definition and location of the planum temporale in the sylvian fossa. Finally, our quantitative analyses are amenable to the use of morphometric techniques in the study of variability in fissurization patterns.

Adult↗
PubMedDate not supplied

Hemispheric contributions to pragmatics.

Twenty-seven patients with right-hemisphere damage (RBD) and thirty-one patients with left-hemisphere damage (LBD) received a new pragmatics battery in Hebrew consisting of two parts: (1) comprehension and production of basic speech acts (BSAs), including tests of assertions, questions, requests, and commands, and (2) comprehension of implicatures, including implicatures of quantity, quality, relevance, and manner. Each test had a verbal and a nonverbal version. Patients also received Hebrew versions of the Western Aphasia Battery and of the Right Hemisphere Communication Battery. Both LBD and RBD patients were impaired relative to controls but did not differ from each other in their overall scores on BSAs and on Implicatures when scores were corrected by aphasia and neglect indices. There was a systematic localization of BSAs in the left hemisphere (LH) but not in the right hemisphere (RH). There was poor localization of Implicatures in either hemisphere. In LBD patients, BSAs were associated with language functions measured with the WAB, suggesting the radical possibility that the classic localization of language functions in aphasia is influenced by the localization of the BSAs required by aphasia language tests. Both BSAs and implicatures show greater functional independence from other pragmatic, language and cognitive functions in the RBD than in the LBD patients. Thus, the LH is more likely to contain an unmodular domain-nonspecific set of central cognitive mechanisms for applying means-ends rationality principles to intentional activity.

Brain↗