Avtor/Urednik		Doty, RW; Fei, R; Hu, S; Kavcic, V
Naslov		Long-term reversal of hemispheric specialization for visual memory in a split-brain macaque
Tip		članek
Vir		Behav Brain Res
Vol. in št.		Letnik 102, št. 1-2
Leto izdaje		1999
Obseg		str. 99-113
Jezik		eng
Abstrakt		Accuracy of response and pattern of ocular fixations in three split-brain macaques were used to evaluate performance of each hemisphere in a continuous visual recognition task. The animal indicated by ocular fixation upon response points whether a displayed image or face was 'NEW' or 'OLD'. An inadvertent lesion of cingulate gyrus severely reduced contralateral fixations and impaired performance of the affected hemisphere in one animal, confirming the inferred relation between hemisphere and laterality of fixations. The hemispheres in the other two animals were initially remarkably similar in accuracy with human faces and with images; but the right hemisphere was significantly superior to the left for macaque faces. Parallel to this, in the one animal tested while simultaneously using both eyes/hemispheres, fixations were made primarily on the left half of human and macaque faces (right hemispheric control), whereas for images the ocular fixations were predominantly focused on the right half. However, after further, extensive training the left hemisphere performed with significantly greater accuracy than the right on all material and this shift was accompanied and further corroborated by a reversal of the fixational pattern to favor the right half of faces, as continued to be the case with images. Thus, over the long term both the pattern of ocular fixations and the accuracy of performance demonstrate a migration from right to left hemispheric dominance as familiarity with the task increased. Performance of the initially superior hemisphere actually diminished with this shift, presenting a uniquely puzzling question of hemispheric balance in the absence of the forebrain commissures.
Deskriptorji		ANIMALS ATTENTION BRAIN MAPPING CEREBRAL CORTEX DOMINANCE, CEREBRAL FACE FIXATION, OCULAR GYRUS CINGULI MACACA NEMESTRINA PATTERN RECOGNITION, VISUAL PRACTICE (PSYCHOLOGY)