The effect of semantic plausibility on sentence comprehension in aphasia

Tested were 50 aphasic patients (16 Broca's, 15 Wernicke's, 10 global, and 9 amnesic), 13 nonaphasic brain damaged patients, and 13 normal adults to evaluate the effect of semantic plausibility on sentence comprehension in active affirmative declarative sentences with a sentence-picture matching task. A plate of two pictures was provided for each stimulus sentence, and the subject was required to choose the picture corresponding to the sentence presented auditorily. Two types of sentences in terms of plausibility were prepared, i.e., probable sentences (P) describing common events in our daily life and improbable sentences (I) describing rare events. There were four kinds of combinations of a picture with the other to make a correct/(distractor) set, i.e., P/(P), P/(I), I/(P), and I/(I) constructions. The results indicated that probable sentences were more comprehensible than improbable sentences, and that the effect of semantic plausibility did not differ among aphasic types.