TESTING CAUSAL THEORIES OF PANTOMIMIC DEFICITS IN APHASIA USING PATH-ANALYSIS

For the past several decades it has been recognized that deficits in b oth pantomime expression and pantomime recognition exist as part of th e syndrome of communication deficits associated with aphasia. To test the major theories proposed to explain the cause(s) of these pantomimi c deficits and their association with aphasic verbal deficits, path an alysis and LISREL were used to analyse five causal models. (Path analy sis is a type of structural equation modelling and LISREL is a compute r program used to assess the models against the obtained data.) Data w ere obtained from 41 left-hemisphere-damaged aphasic subjects. The res ults of the path and LISREL analyses led to the rejection of four of t he five models. Three of the four rejected models tested asymbolia, in tellectual loss, limb apraxia, and visual processing deficit as sole c ausal factors; the fourth rejected model was a multicausal model testi ng intellectual loss, limb apraxia, asymbolia, and visual processing d eficit. The one model that proved to be plausible was a multicausal mo del hypothesizing that pantomimic recognition and expression deficits were caused both by a central symbolic deficit and specific modality f actors of limb apraxia and visual processing.