ASYNTACTIC THEMATIC ROLE ASSIGNMENT - THE USE OF A TEMPORAL-SPATIAL STRATEGY

We report syntactic comprehension performance of a left-handed man wit h a right-hemisphere infarct. He was unable to accurately map grammati cal categories (subject, object) onto thematic roles (agent, patient), despite demonstrating intact conceptual knowledge of these thematic r oles. He performed poorly on both active and passive reversible senten ces. His asyntactic thematic role assign ment cannot be accounted for by a short-term memory impairment or any hypothesis that predicts sele ctive vulnerability to passive sentence constructions. Rather than per forming randomly, our patient used a temporal or spatial strategy in a ssigning thematic roles. Because he also had a production-mapping defi cit and used the same temporal-spatial strategy in production tasks, w e hypothesize that the mapping of thematic roles onto grammatical cate gories and vice versa may be a specific aspect of sentence processing that is common to sentential production and comprehension. We also rai se the possibility that thematic roles have underlying spatial represe ntations prior to being elaborated by grammar. (C) 1995 Academic Press , Inc.