EEG evoked response, P300 and CNV during processing of sentence information: clinical application.

Evoked response, P300 and CNV were investigated in the condition in which the subject was required to make a differential response to the acoustically and visually presented sentence with or without meaning, and he was able to determine whether the sentence had a meaning or not by understanding the key information. In healthy persons, P300 amplitude to the beginning of information and to the key information were larger than those to the others. P300 latency to the key character was longer. CNV appeared at the beginning of information and continued. The difference between CNVs produced by meaningful and meaningless sentences was observed after the key information. In aphasia, the difference between CNV's was not observed. In auditory agnosia, the difference between CNVs was not observed to acoustic sentences, but appeared to visual sentences. These results suggest that evoked response, P300 and CNV can be useful for assessing recognition of sentences.