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Biomedical subjects

R Bruyer

Publications and source records attributed to R Bruyer.

69 records · Page 4Linked to original sources
PubMed1981

[Unilateral cerebral lesion and disturbance of face perception. Specificity of the deficit? (author's transl)].

Twenty normal subjects, twenty subjects with a left hemispheric lesion and ten patients with a right-side lesion were tested for visual perception of various categories of complex, not readily verbalizable stimuli : human faces, dog faces, "faces" of motor vehicles, facades of houses. The purpose of the work was to explore the theory that the right hemisphere accomplishes treatment processes specific to faces presented the right way round. A classification pre-test and identification pre-test were followed by a test in which the patient had to identify a model in a group of stimuli of different categories, the material being presented either the right way or the wrong way round. The results bear out the reports in the literature ; they show particular fragility on the part of subjects with right-side lesions confronted with human faces. The data also bear out the theory of specificity, provided that the "face" concept is taken to include all living faces (dogs and human beings).

Adult↗
PubMed1980

[Verbal fluency and lesion of the cerebral cortex (author's transl)].

The words fluency test (Ramier and Hecaen, 1970, 1977) is administered to 91 brain damaged right-handed subjects. Groups are constructed according to lesional lateralisation, frontal localisation of lesions and presence of aphasia. Total number of productions, nubmer of correct responses, number and types of errors, number of pathological subjects are studied. It appears that aphasic patients and subjects with frontal brain damage are deficient, but the effect of the lateralisation of the lesion is not observed. Aphasic patients produce other errors (neologisms, proper nouns, repetitions) than subjects with frontal damage (inability to change the initial letter after appropriate instructions).

Adult↗
PubMed1977

[Transient agraphia due to a left parieto-occipital glioma in a right-handed patient: amnesic or "pure" agraphia? (author's transl)].

The authors investigate a case of agraphia induced by a left parieto-occipital tumor (glioma) in a right-handed 67 year-old patient. After three successive neuropsychological examinations it still proves immensely difficult to determine whether defects of spontaneous writing, dictation and copy are due to apraxia, alexia or motor disturbances. The authors discuss whether the clinical findings indicate a "pure agraphia" syndrome or "amnesic agraphia". Finally, problems of aetiology and lesional localisation are examined in the light of the literature. (Acta neurol. belg., 1977, 77, 321-330).

Adrenal Cortex Hormones↗
PubMedDate not supplied

The fate of global precedence with age.

The literature is virtually devoid of studies examining the effect of aging on the "global precedence" effect (Navon, D. [1977]. Cognitive Psychology, 9, 353-383). In this paradigm, global letters formed with local letters are shown, and the subject has to recognize either the local or the global letters. The relation between the global and the local letters is either congruent, neutral, or conflicting. Five experiments are reported, with five sets of 16 young and five sets of 16 elderly, healthy, adult subjects. The global precedence effect was observed in both age groups in the basic perceptual experiment as designed by Navon (Experiment 1). In addition, young and elderly subjects were able to process separately the global and the local shapes when attention was not directed towards a specific level (Experiment 1a). However, subpopulations emerged, especially in the elderly, depending on their ability to "resist" to the interference of the global shape upon the processing of the local form. This could support the few indirect published data suggesting that global precedence tends to diminish or to disappear with age. In experiments 2 and 2a, subjects were retained only if they did process the local level better than at random. Global precedence was confirmed in both young and elderly subjects. Again, elderly subjects manifested an increased sensitivity to interference. Moreover, a general effect of age remained, even in the control (neutral) conditions, suggesting difficulties of encoding in elderly. Therefore, in Experiment 3, encoding conditions of both age groups were equated by increasing exposure duration of the material for elderly. Subjects of Experiment 3 were also submitted to a Stroop test, to verify whether the increased sensitivity to interference in the elderly was specific to the "Navon task" or the expression of a general effect of aging on inhibition mechanisms. The global precedence phenomenon was observed in young and elderly subjects, with no sign of an effect of age under these conditions; in elderly, furthermore, the interference effect did not appear to result from a general aspecific deficit of inhibition mechanisms. It thus appears that the global precedence phenomenon resists well the effects of aging, but that subpopulations of elderly subjects should be considered in future studies.

Adolescent↗
PubMedDate not supplied

Effects of aging on the generation of mental images.

Image generation is one component of mental imagery, and consists in the activation of stored visual information in long-term memory to sequentially create a temporary pattern on a visuospatial short-term memory display. Little is known about the fate of image generation over the human life span. In the present study, 165 healthy participants aged 18 to 80 years were enrolled for an image generation task to image an uppercase letter in response to its lowercase version displayed as the cue, and to decide if a displayed probe would be near to or on the image. Uppercase letters were simple versus complex, and the probe appeared in a region of the uppercase letter that is generated early versus late. Comparative analyses (ANOVAs) on accuracy and correct latency confirmed the sequential nature of image generation, and showed a detrimental and linear effect of aging only on the activation subprocess. Structural analyses (LISREL) revealed, however, that these effects of age were entirely mediated by inhibition mechanisms, speed of processing, and working memory.

Adolescent↗
PubMedDate not supplied

[The brain and the visual recognition of human faces (author's transl)].

The first part presents some studies in normal subjects. We observe that faces recognition is a very primitive behavior in human child, that the symmetry and some parts of a face may play a specific role, and that the right cerebral cortex is dominant for this function. Problems of specificity are also examined. Studies in pathological subjects are then presented. We examine some publications concerning child's psychiatry and neurology. Prosopagnosia, his associated symptoms, and the anatomical questions are then considered. Finally we examine researches concerning the relationships between brain lesions and the recognition of human faces, with a special attention to the mnesic processes and to the questions of specificity.

Adult↗
PubMedDate not supplied

[Semiology of bismuth encephalopathy. Comparison with seven personal cases (author's transl)].

The authors analyze 99 well-described cases of bismuth encephalopathy and suggest a clinical syndrome according to three stages of the disease (before, during and after the acute period) and three clinical domains (psychiatry, neurology and neuropsychology). A particular attention concerns the presence of sequellar clinical signs (mnesic functions), sometimes observed one year after interruption of bismuth ingestion.

Age Factors↗
PubMedDate not supplied

[Neuropsychology and psychological testing: boundaries and proximity (author's transl)].

The psychological testing is briefly described and we present the fields of proximity between neuropsychology and psychometry (psychosurgery and aphasiology. Yet it appears that usefulness of psychometry in neuropsychology is only limited to practical aspects. The main limitation arises from two problems: non-neuropsychological goal of psychometry and non-functional and quantitative studies of behavior. A specific "neuropsychometry" is presented and examples are suggested from studies of italian, soviet (Luria's school) and swiss (Piaget's method) researchers; applications in clinical neuropsychology are discussed. In conclusion, neuropsychology must produce a functional analysis of behavior and conceive this behavior as a reorganisation rather than a deficit or a loss.

Factor Analysis, Statistical↗
PubMedDate not supplied

Brain damage and person perception. Discrimination of handwriting.

Like the face or the voice, handwriting is a parameter enabling the perception of persons. The right hemisphere appears to predominate in the processing of voices and faces, especially when a discriminative procedure is used. In order to see if this brain asymmetry may be generalized to person perception, a handwriting discrimination task was submitted to 15 left-, 12 right-, and two bilaterally injured subjects. The subject was asked to decide whether two simultaneously presented stimuli had been written by the same person; 72 pairs were presented in three ways: normally, inverted, and mirror-reversed. The results suggest that such processing is essentially preserved after focal brain damage; defects were found only after right lesions inducing hemineglect, after bilateral posterior lesion, and after left lesion when stimuli were displayed upside-down or mirror-reversed (i.e. unreadable).

Brain↗
PubMedDate not supplied

[Differential implication of cerebral hemispheres in emotional behavior (author's transl)].

Current neuropsychology states that the right cerebral hemisphere is dominant in emotional situations and emotional responses. The author suggests that various results must clarify this concept. This predominance seems to be prevalent in negative emotions, while positive emotions are mainly processed through the left hemisphere. There is thus no hemispheric asymmetry but rather a hemispheric differentiation in function of the nature of the emotion. The explanation of this double asymmetry remains to be clarified.

Animals↗
PubMedDate not supplied

[Pure bilateral agraphia, right astereognosia and arithmetic defects associated with a left parietal tumor (author's transl)].

A case of bilateral agraphia produced by a left parietal glioma is described in a 49 year-old right-handed woman. Hypothesis of a pure agraphia, etiology and non-frontal localisation of tumor are discussed. This agraphia is associated to a right astereognosia; neither functional nor behavioral relationships are found between these two defects, and it appears that their are probably associated according to the parietal locus of lesions.

Agraphia↗
PubMedDate not supplied

[Neuropsychology and self perception].

The contribution of clinical and experimental neuropsychology to the genesis of identity is studied through the constitution of body image. The perceptual aspects are only considered and the body and face perceptions are distinguished. In both cases, pathological and experimental facts are described. It appears that neuropsychology can validate hypotheses of general psychology and brings into light new variables to be integrated into the psychology models.

Body Image↗
PubMedDate not supplied

[Color agnosia: a brief review].

An introductory historical reminder situates the problem of color agnosia in the global frame of neuropsychological research and emphasizes the relevance of old questions. One examines later the description of agnosia, which indicates the polymorphic character of this trouble, its limits concerning linguistic and perceptual troubles, and the principal associated symptoms. The most important explanatory hypothesis are also studied, mainly according to the Italian school of Milan (conceptual and associative deficit) and the group of "La Salpétrière" in Paris (regression of past-acquisitions). The methodology then describes the most frequent means used in neuropsychology to analyze color agnosia. Finally, questions of anatomy and lesional localisation (left associative visual cortex) are also described.

Agnosia↗