Critical reading at the sentence level in aphasia.

A sentence-reading test was devised in order to assess the aphasic's ability to detect errors in written discourse. One hundred pairs of sentences, each containing one correct and one erroneous sentence, were presented to the patients, who were required to locate the error in one of the two sentences. So that comprehension in the auditory and visual modalities might be compared, the identical test was administered orally to a subset of the aphasic population. Contrary to expectations, there was no difference in overall scores between patients with anterior and posterior pathology. Anterior patients performed somewhat better on the oral version, posterior patients on the written version of the test. Finally, an examination of errors revealed a regular order of difficulty in sentences which featured contradictions to "real-world" knowlege, irrespective of the locus of brain damage, while the order of difficulty of sentences featuring syntactic deviations differed appreciably, depending on the locus of lesion. An attempt is made to relate these findings to current experimental and clinical knowledge.