Publications by authors named "HECAEN H"

An analysis of the concurrent incidence of aphasia and spatial disorder in 270 patients with unilateral brain damage suggests that the two functions are statistically independent. These data can also be used to estimate the distribution of left, right, and bilateral representation of linguistic and spatial functions in the population. In right-handers, sex affects the pattern of cerebral asymmetries, while the familial history of sinistrality has a stronger effect on the pattern of cerebral asymmetries in left-handers.

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Observations of acquired aphasia in a more numerous series of children with cortical lesions modifies somewhat the conclusions of an earlier study. Aphasic syndromes in these children seem to result almost exclusively from left hemispheric lesions in right-handers. Aphasia is more frequent, at least among the youngest children, than in adults.

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A case of cortical blindness resulting from a dense ischemic lesion of both calcarine cortices (as seen on CAT Scan) was studied up till the seventh month after the initial stroke. By using mainly forced-choice procedures, similar to those previously used for testing hemianopic subjects, we were able to demonstrate the reappearance of some visual capacities, even though the patient still behaved as if completely blind in everyday life and the lesion remained as it was first seen. First, an ability to detect moving stimuli reappeared then bright flashes could be detected.

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A case is reported in which a patient with a vascular accident involving the posterior portion of the minor hemisphere presented a topographic memory loss and also deficits in his ability to learn certain types of new material. The study of this case has led us to re-examine spatial functioning in light of both human and animal research. Based on clinical and experimental evidence we have proposed that a unitary interpretation can account for the various spatial deficits associated with posterior righ hemisphere lesions.

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Neuropsychology is a new discipline placed between neurosciences (neurophysiology, neurochemistry, comparative neuroanatomy) and psychology (experimental psychology. psycholinguistics, linguistics). History of neuropsychology shows, during last and the beginning of the present centuries, a marked trend to localization and association (one center for each function, followed later by a period where globalistic trends predominate, according to which a localized lesion is important mostly because of the modification it produces in the functions of brain as a whole.

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In contrast to findings in right-handed subjects with a unilateral hemispheric lesion, in the left-handed there is no significant difference in "verbal fluency) test scores between right and left lesions, nor between anterior and posterior lesions. These findings are in favour of a certain degree of cerebral ambilaterality and of a lesser focalisation of the mechanisms responsible for language in the left-handed than in the right right-handed.

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Two optico-geometrical illusions--the Müller-Lyer (ML) and the Ponzo (P) illusion--have been studied in normal subjects and in patients with unilateral cortical lesions. Patients with left-sided lesions have stronger illusions than normal subjects, the increase being significant only for the ML illusion. In the case of right-sided lesions, the P illusion is weakened while the ML illusion is equivalent to that of control subjects.

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The hypothesis is advanced that cerebral dominance includes two elements, interhemispheric specification for language (lateralization) and intrahemispheric language, specification (localization). Consequently, each type of aphasia is determined by the degree of dominance establishment (i.e.

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The relationship of disturbances of the body schema to hemispheric locus of lesion and sensory aphasic disorder was assessed by giving verbal and non-verbal tests of right-left orientation, finger recognition, and autotopagnosis to patients with unilateral cerebral disease. The study was restricted to right-handed patients who were free from general mental impairment or confusion. The tests were also given to a group of control patients whose performances defined the range of normal performance in each test.

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