SEMANTIC, PHONOLOGICAL, AND PERCEPTUAL CHANGES FOLLOWING LEFT AND RIGHT INTRACAROTID INJECTION (WADA) WITH A LOW AMYTAL DOSAGE

Intracarotid injection of a low dosage of amobarbital (75 mg, 5% solut ion) was studied in 30 temporal lobectomy candidates while naming achr omatic, incongruously, and congruously colored pictorial objects and r eading real, nonsense, and embedded words. Semantic errors and phonolo gical alexia followed the left injection, while the right injection in duced visuoperceptual errors. When the contralateral hemisphere was an esthetized, the left brain formulated supraordinate categories for wor ds and objects, while the right brain applied concrete labels. The bas ic language proficiency of patients influenced recovery and outcome; l eft temporal patients who were interictally anemic performed especiall y poorly after both injections. Codifying phonological and perceptual changes during the intracarotid amobarbital procedure can improve inte rpretations about language laterality and organization. (C) 1997 Acade mic Press.