We studied with PET the intra- and interhemispheric pathways subserving a simple, speeded-up visuomotor task. Six normal subjects and one patient with a complete section of the corpus callosum (M.E.) underwent regional cerebral blood flow (rCBF) measurements under conditions of lateralized tachistoscopic visual presentations in a simple manual reaction time paradigm. Confirming previous behavioural findings, we found that on average crossed hand and/or hemifield conditions, i.e. those requiring an interhemispheric transfer of information, yielded a longer RT than uncrossed conditions. This difference (0.7 ms) was dramatically larger (45.6 ms) in the callosum-sectioned patient M.E. In normal subjects the cortical areas selectively activated in uncrossed and crossed conditions were different. In the former condition, most activation foci were anterior to the ventral anterior commissure (VAC) plane, whereas in the latter there was a prevalent parietal and occipital activation. This shows that a simple model in which the cortical visuo-motor pathways are similar in the intra- and the interhemispheric condition, with an extra callosal route for the latter, is too simplistic. Furthermore, these results suggest that the bulk of visuomotor interhemispheric transfer takes place through the widespread callosal fibres interconnecting the parietal cortices of the two hemispheres. The pattern of activation in the two crossing conditions was markedly different in M.E., in whom interhemispheric transfer might take place via his intact anterior commissure or subcortical commissures

Marzi, C., Perani, D., Tassinari, G., Colleluori, A., Maravita, A., Miniussi, C., et al. (1999). Pathways of interhemispheric transfer in normals and in a split-brain subject. A positron emission tomography study. EXPERIMENTAL BRAIN RESEARCH, 126(4), 451-458 [10.1007/s002210050752].

Pathways of interhemispheric transfer in normals and in a split-brain subject. A positron emission tomography study

MARAVITA, ANGELO;PAULESU, ERALDO;SCIFO, PAOLA VITTORIA;FAZIO, FERRUCCIO
1999

Abstract

We studied with PET the intra- and interhemispheric pathways subserving a simple, speeded-up visuomotor task. Six normal subjects and one patient with a complete section of the corpus callosum (M.E.) underwent regional cerebral blood flow (rCBF) measurements under conditions of lateralized tachistoscopic visual presentations in a simple manual reaction time paradigm. Confirming previous behavioural findings, we found that on average crossed hand and/or hemifield conditions, i.e. those requiring an interhemispheric transfer of information, yielded a longer RT than uncrossed conditions. This difference (0.7 ms) was dramatically larger (45.6 ms) in the callosum-sectioned patient M.E. In normal subjects the cortical areas selectively activated in uncrossed and crossed conditions were different. In the former condition, most activation foci were anterior to the ventral anterior commissure (VAC) plane, whereas in the latter there was a prevalent parietal and occipital activation. This shows that a simple model in which the cortical visuo-motor pathways are similar in the intra- and the interhemispheric condition, with an extra callosal route for the latter, is too simplistic. Furthermore, these results suggest that the bulk of visuomotor interhemispheric transfer takes place through the widespread callosal fibres interconnecting the parietal cortices of the two hemispheres. The pattern of activation in the two crossing conditions was markedly different in M.E., in whom interhemispheric transfer might take place via his intact anterior commissure or subcortical commissures
Articolo in rivista - Articolo scientifico
Magnetic Resonance Imaging; Reference Values; Humans; Brain; Corpus Callosum; Cerebrovascular Circulation; Regional Blood Flow; Cerebral Cortex; Brain Mapping; Adult; Tomography, Emission-Computed; Psychomotor Performance; Models, Neurological; Visual Pathways; Functional Laterality; Male
English
451
458
8
Marzi, C., Perani, D., Tassinari, G., Colleluori, A., Maravita, A., Miniussi, C., et al. (1999). Pathways of interhemispheric transfer in normals and in a split-brain subject. A positron emission tomography study. EXPERIMENTAL BRAIN RESEARCH, 126(4), 451-458 [10.1007/s002210050752].
Marzi, C; Perani, D; Tassinari, G; Colleluori, A; Maravita, A; Miniussi, C; Paulesu, E; Scifo, P; Fazio, F
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/35090
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