Visuospatial functioning before and after commissurotomy. Disconnection in hierarchical processing
D. C. Delis, J. H. Kramer and M. G. Kiefner
Psychology Service, Veterans Administration Medical Center, San Diego, CA 92161.
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.
