Mild closed head injury and seizures.
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Craniocerebral Trauma↗
Biomedical subjects
J E Bogen
Publications and source records attributed to J E Bogen.
Completeness of callosotomy shown by magnetic resonance imaging in the long term.
Six individuals who had complete cerebral commissurotomy for medically intractable epilepsy participated in a magnetic resonance imaging study 20 or more years postoperatively. In all cases the completeness of callosotomy was clearly demonstrable. The status of the anterior commissure, cut in all six, could not be confirmed with the same confidence.
Corpus Callosum↗
Creativity and the corpus callosum.
A duality of mind is readily demonstrable in split-brain humans, and evidence is steadily accumulating that ongoing interhemispheric communication is incomplete in the intact brain. It is now certain that the corpus callosum can transfer high-level information from one hemisphere to another. When we take into account the well-established principle of hemispheric specialization, added to the impressive normality of split-brain humans in ordinary social situations, a physiologic explanation for at least some forms of creativity seems close at hand. What is required is a partial (and transiently reversible) hemispheric independence during which lateralized cognition can occur and is responsible for the dissociation of preparation from incubation. A momentary suspension of this partial independence could account for the illumination that precedes subsequent deliberate verification. From this point of view, we can understand better the opinion of Frederic Bremer, who wrote years ago that the corpus callosum subserves "the highest and most elaborate activities of the brain"--in a word, creativity.
Animals↗
Alexithymia and the split brain: VI. Electroencephalographic correlates of alexithymia.
Electroencephalographic recordings of eight corpus callosotomy patients and eight precision-matched control subjects were obtained as subjects watched a film symbolically depicting death. A content-analytic measure of alexithymia was regressed on eight auto-spectral alpha-band intensity averages and on subsets of alpha-band coherence averages. Results were interpreted on the basis of three possible mechanisms of alexithymia: (1) Alexithymic subjects had more right-temporal alpha-band intensity, suggesting inadequate understanding of the film. (2) A possible lack of inner speech in alexithymics was suggested by their relative alpha abundance of the left frontal and left temporal channels but left parietal alpha desynchronization, and by their lower left frontotemporal but higher left parietofrontal and left parietotemporal coherences. (3) Alexithymic subjects had higher right frontal-left parietal and left frontal-left parietal coherences, suggesting possible interhemispheric inhibition of expression. Expressive subjects had higher right frontal-left temporal (and homologous interhemispheric frontal, parietal, and frontal) coherences, suggesting interhemispheric facilitation of verbal expression.
Adult↗
Alexithymia and the split brain. V. EEG alpha-band interhemispheric coherence analysis.
Electroencephalographic (EEG) recordings were obtained while 6 completely commissurotomized patients, 2 partially commissurotomized patients, and 8 precision-matched normal control subjects watched 4 times a film symbolically depicting death. Our hypothesis was that alexithymia--a diminished capability to verbally express moods, symbols, and feelings--would be greater for patients because loss of cerebral commissures reduces interhemispheric communication, separating right-hemisphere-dependent affective understanding and left-hemisphere-dependent verbalization. Path and covariance structure analyses confirmed that callosotomy decreased alpha-band EEG coherences (after adjustment for mean intrahemispheric coherence) between pairs of scalp electrode channels placed homologously over frontal, parietal, and temporal lobes of the brain. This result occurred both for an index of interhemispheric coherence and for a latent variable indicated by the 3 adjusted coherences. Reduced levels of interhemispheric coherence in turn increased alexithymia, for an overall index and for a latent variable indicated by lexical-level content-analytic measures of verbal responses to the filmic stimulus.
Adult↗
Are unilateral right posterior cerebral lesions sufficient to cause prosopagnosia? Clinical and radiological findings in six additional patients.
Controversy has arisen regarding the neuropathological basis of prosopagnosia. Some investigators suggest that bilateral lesions are needed to cause the deficit, whereas others felt that a unilateral right posterior lesion is sufficient. Six patients with prosopagnosia with clinical and radiological evidence of unilateral right posterior lesions are presented. Our observations together with evidence from similar cases described in the literature suggest that an appropriately placed right hemispheric lesion may be sufficient to produce prosopagnosia.
Agnosia↗
Alexithymia: an experimental study of cerebral commissurotomy patients and normal control subjects.
This study assessed alexithymia in six patients with complete cerebral commissurotomy, two patients with partial commissurotomy, and eight matched control subjects. Comparisons were based on content-analytic measures of the subjects' spoken and written responses to a film that symbolically represented death and loss. The commissurotomized patients were more alexithymic on all four lexical-level variables, all six sentential-level variables, and all six global-level variables. Discriminant function analysis found a linear combination of four variables that effectively discriminated groups of fully commissurotomized, partially commissurotomized, and normal control subjects and correctly classified 15 of the 16 subjects.
Adult↗
Mental duality in the intact brain.
It has been a signal honor to be president of the Los Angeles Society of Neurology and Psychiatry, which supported for 50 years a forum (the Bulletin of the Los Angeles Neurological Societies) for other than routine views, including those of its famous founders. One of these was Dr. J. M. Nielsen. I remember one of his brain cuttings relevant to this paper: After someone had read the history, he said, "Let's look at the anterior commissure." He held the brain with one hand and that big knife in the other (as you know, the anterior commissure is shaped like a handlebar mustache) and he made one curving sweep through the brain; then he lifted off the top half, and there was the full extent of the commissure. Another Founder, Dr. Cyril Courville taught me as a neurology resident for a year, followed by my time with Dr. Philip Vogel, whose skill and intestinal fortitude resurrected cerebral commissurotomy (1). Dr. Courville, as Editor of the Bulletin, was succeeded by Dr. Clarence Olsen who was succeeded in the Bulletin's 30th year by Dr. Richard Walter. This paper is an extension, to some extent, of my articles called The Other Side of the Brain which were published in the Bulletin in 1969 (2-4). Those articles presented ideas some of which may now seem fairly orthodox. But in those days they were not, and I think that Dr. Walter's publishing them was a tribute to his wry sense of humor, as well as his historical perspective.
Brain↗
Alexithymia and the split brain. I. Lexical-level content analysis.
8 cerebral commissurotomy patients and 8 precision-matched normal control subjects were shown a 3-minute videotaped film symbolically depicting the deaths of a baby and of a boy. After each of 4 showings, all subjects were questioned about the symbolic and emotional contents of the film. Content analyses of the subjects' spoken and written responses were carried out on the lexical level. The commissurotomized patients, in comparison to their normal controls, used a lower percentage of affect-laden words, had a higher percentage of incomplete sentences, used a higher percentage of auxiliary verbs, and used a lower percentage of adjectives. Commissurotomy patients were significantly closer to the alexithymic pole of a factor derived from these 4 variables.
Adult↗
Alexithymia and the split brain. II. Sentential-level content analysis.
The Hoppe-Bogen finding of alexithymia in 12 commissurotomy patients is examined, using 6 sentential-level items corresponding to 6 of the 8 key alexithymia items in the Beth Israel 'Psychosomatic Questionnaire'. 8 of the same commissurotomy patients and 8 precision-matched normal control subjects were shown a 3-min videotaped film about death. Content analyses of the subjects' spoken and written responses to this film were carried out, with directional support found for all items; however, only 2 of these differences in group means were statistically significant. The items were factor analyzed, and a 1-factor solution obtained. Factor score comparisons replicated the earlier study, as commissurotomy patients were found to be more alexithymic than normal controls.
Affective Symptoms↗
Alexithymia and the split brain. III. Global-level content analysis of fantasy and symbolization.
8 commissurotomy patients and 8 precision-matched normal control subjects were shown a 3-min videotaped film about death. Content analysis of the subjects' spoken and written responses to this film was carried out on the global, interpretive level, for 2 fantasy and 4 symbolization variables. Commissurotomy patients were found to be significantly more alexithymic than normal controls for 3 of the symbolization variables, for factor-analytic measures of fantasy and symbolization, and for an over-all measure of alexithymia derived from these 2 factors and lexical-level and sentential-level measures of alexithymia.
Affective Symptoms↗
Alexithymia and the split brain. IV. Gottschalk-Gleser content analysis, an overview.
A structural explanation of psychosomatic personality structure is proposed, that of a functional or physical deconnection of the two cerebral hemispheres. If the affective and symbolic energies of the right hemisphere cannot be externalized through verbal expressions of the left hemisphere (alexithymia), then they are apt to be directed inward, thereby contributing to psychosomatic personality structure. In an experiment, 8 cerebral commissurotomy patients and 8 precision-matched normal control subjects were shown a 3-minute videotaped film symbolically depicting the deaths of a baby and a boy. Gottschalk-Gleser content analysis of the subjects' verbal responses to the film was carried out for anxiety and hostility scales. A complex of shame and total anxiety in combination with hostility directed both inward and outward, was interpreted as an indicator of 'psychosomatic personality structure'. Cerebral commissurotomy patients showed a significantly higher level of psychosomatic personality structure than did normal controls.
Affective Symptoms↗
Cultural hemisphericity: evidence from cognitive tests.
Cultural differences in appositional abilities were investigated. Items from two gestalt completion tests were modified to examine the effects of stimulus manipulations (e.g., background color, presence of details) on previously observed ethnic differences in performance. Overall, black subjects again scored higher than white subjects; women scored higher than men. However, these differences varied with certain stimulus manipulations. These findings suggest that, by investigating gestalt completion, we can better understand the cognitive factors underlying appositional abilities.
Black or African American↗
Alexithymia in twelve commissurotomized patients.
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Adult↗
Transcallosal approach to third ventricle tumor: case report. Partial removal of an infundibuloma (grade I astrocytoma arising from the floor of the third ventricle).
A care is described of an astrocytoma grade 1 arising from the floor of the third ventricle, operated upon transcallosally. No disconnection symptoms were produced. Five years later the patient has above normal intelligence and is attending school at normal grade level in spite of a CT scan suggesting recurrence of the tumor.
Astrocytoma↗
The grasp reflex of the foot and related phenomena in the absence of other reflex abnormalities following cerebral commissurotomy.
The grasp reflex of the foot and related pheonomena were examined in six subjects with no abnormalities of deep tendon or plantar (and related) reflexes 6 to 10 years after cerebral comissurotomy. In all subjects they were more marked on the same side as the more damaged hemisphere. These tonic phenomena seem to be facillitated by sitting and standing postures. Practical and theoretical implications of the tonic foot responses in the absence of similar phenomena of the hand are discussed.
Adult↗
Wernicke's region--Where is it?
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Aphasia↗
More on the question of cultural hemisphericity.
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Cultural Characteristics↗