BRAIN AND LANGUAGE 13, 201-211 (1981) Selective Semantic-Lexical Impairment of Language Comprehension in Right-Brain-Damaged Patients GUIDO GAINOTT], CARLO CALTAGIRONE, GABRIELE MICELI, AND CARLO MASULLO Institute of Neurology, Catholic University, Rome Fifty right-brain-damaged patients and thirty-nine normal controls were given two tests of semantic-lexical discrimination (auditory language comprehension and reading comprehension) and a test of phoneme discrimination. The aims of the research consisted in checking: (A) if right-brain-damaged patients are signifi- cantly more impaired than normal controls on the tasks of semantic discrimina- tion even when the influence of associated variables (such as unilateral spatial neglect or general mental impairment) is ruled out; and (B) if semantic-lexical disorders of right-brain-damaged patients are selective or if they are associated with disorders of phoneme discrimination. Results have shown that right hemi- spheric lesions consistently impair semantic-lexical discrimination but do not hamper phoneme discrimination. Some implications of these results are dis- cussed. The question of the language capabilities of the right (nondominant) hemisphere has received increasing attention in recent years and the topic has been recently reviewed by Hecaen (1976) and by Searleman (1977). Evidence for a contribution of the right hemisphere to language functions comes from different lines of research: (a) investigation of split-brain patients (Gazzaniga & Sperry, 1966;Sperry & Gazzaniga, 1967;Gazzaniga, 1970; Levy & Trevarthen, 1977; Zaidel, 1976, 1977, 1978); (b) study of the residual linguistic capabilities after left hemispherectomy (Smith, 1966; Gott, 1973; Burklund & Smith, 1977); (c) reports of subtle linguistic deficiencies after right-hemisphere damage (Eisenson, 1962; Critchley, 1962; Marcie, Hecaen, Dubois, & Angelergues, 1965; Zangwill, 1967; Caramazza, Gordon, Zurif, & Deluca, 19%; Kim, 1976); (d) research conducted on normal subjects with the dichotic listening technique (Shankweiler & Studdert-Kennedy, 1967, 1975; Zurif, 1974) or with Address reprint requests to: Guido Gainotti, Clinica Neurologica, Universit& Cattolica, Large A. Gemelli, 8, 00168 Rome, Italy. 201 0093-934X/81/040201-11$02.00/0 Copyright 0 1981 by Academic Press, Inc. All rights of reproduction in any form reserved.