Verification of active and passive sentences by aphasic and nonaphasic subjects.

Aphasic and nonaphasic subjects participated in a sentence verification task in which they were asked to judge whether spoken sentences correctly described pictures presented with the sentences. True active and true passive sentences were presented, as well as, false active and passive sentences in which agents and objects were reversed. In addition, false active sentences in which either the subject, verb, or object did not match the picture were presented. Subjects' response accuracy and reaction times were recorded. Passive sentences were more difficult than active sentences for both groups of subjects, and false sentences were verified more quickly than true sentences for both groups. Both groups appeared to be processing sentences for meaning as they were received, rather than waiting for the entire sentence before beginning to process it for meaning. In general, performance of aphasic subjects resembled that of nonaphasic subjects, except that aphasic subjects consistently took longer to verify sentence meaning than nonaphasic subjects.