Visuospatial functioning before and after commissurotomy. Disconnection in hierarchical processing.

A patient who underwent complete cerebral commissurotomy was tested before and after surgery on tasks involving drawing and recognition memory for visual hierarchical stimuli. These stimuli consisted of a large, higher-level form constructed from smaller, lower-level forms. Postoperatively, the patient was more accurate in drawing and recognizing higher-level forms relative to lower-level forms when responding with his left hand and primarily right hemisphere, whereas he showed the opposite pattern when responding with his right hand and primarily left hemisphere. Implications of these findings for theories of the cerebral organization of visuospatial processing are discussed.

[1]  D. Delis,et al.  Hemispheric specialization of memory for visual hierarchical stimuli , 1986, Neuropsychologia.

[2]  S. Kosslyn,et al.  A computational analysis of mental image generation: evidence from functional dissociations in split-brain patients. , 1985, Journal of experimental psychology. General.

[3]  M S Gazzaniga,et al.  Facial recognition and brain asymmetries: Clues to underlying mechanisms , 1983, Annals of neurology.

[4]  J. Sergent.  The cerebral balance of power: confrontation or cooperation? , 1982, Journal of experimental psychology. Human perception and performance.

[5]  E. Renzi.  Disorders of space exploration and cognition , 1982 .

[6]  Maryanne Martin,et al.  Hemispheric specialization for local and global processing , 1979, Neuropsychologia.

[7]  M. Moscovitch.  Information Processing and the Cerebral Hemispheres , 1979 .

[8]  R. Nebes.  Perception of spatial relationships by the right and left hemispheres in commissurotomized man. , 1973, Neuropsychologia.

[9]  R Tissot,et al.  Qualitative analysis of unilateral spatial neglect in relation to laterality of cerebral lesions , 1972, Journal of neurology, neurosurgery, and psychiatry.

[10]  E. Kaplan,et al.  The assessment of aphasia and related disorders , 1972 .

[11]  R. Nebes.  Superiority of the minor hemisphere in commissurotomized man for the perception of part-whole relations. , 1971, Cortex; a journal devoted to the study of the nervous system and behavior.

[12]  E K Warrington,et al.  Drawing disability in relation to laterality of cerebral lesion. , 1966, Brain : a journal of neurology.