Dyspraxia following division of the cerebral commissures.

The BASIC picture of the cerebral deconnection or split-brain syndrome 1 has been extended and elaborated in recent years through the study of some patients in whom cerebral commissurotomy had been carried out by P. J. Vogel at the White Memorial Medical Center, Los Angeles, in an effort to curb severe epileptic seizures not controlled by medication. 2,3 Earlier descriptions of these cases dealing with visual, tactual, and language functions primarily indicate that the two separated hemispheres function quite independently with respect to most mental or gnostic activities. 4-8 In brief, speech, writing, and calculation, plus visual gnosis for the right half visual field and stereognosis of the right hand, were found to be lateralized in the dominant left hemisphere, while stereognosis of the left hand and visual gnosis of the left half visual field were found restricted to the right minor hemisphere. Other functions including some aspects of language