A study of eight adult chronic aphasic patients' comprehension of sentences and pictures in which comparisons of time and space were crucial was designed to assess A. R. Luria's approach to designing comprehension test tasks. The investigation required patients, with lesions of varying size and location, to determine whether a sentence expressing temporal or spatial relations or a physical comparison corresponded to a picture presented with it. It was found that comparatives were easiest for the patients to understand, while spatial relations were more difficult, and the temporal relations expressed in the items were almost impossible for the patients to handle. It is concluded that Luria's writings about semantic aphasia and the processing of sentences expressing relationships should be modified, because in this study all aphasics, regardless of lesion site, were especially impaired on sentences where grammar governs syntax and grammatical markers are clearly abstract. According to Luria's theory, the patients' responses should have varied according to lesion site. It is suggested that Luria comes close to contradicting himself in proposing that one brain region should be more important than others in processing relatively complex sentences. (MSE)