NEUROPHYSIOLOGICAL CORRELATES OF MEANINGFUL AND NONMEANINGFUL SENTENCE PROCESSING (EVOKED, RESPONSE, POTENTIALS).

摘要

Event related potentials (ERPs) were utilized to investigate the influence of sex and presentation on meaningful and nonmeaningful sentence processing. Amplitude and latency values were recorded from a central (Cz) and left parietal (P3) electrode locating beginning with the onset of the last (Key) word or nonsense syllable in the sentence. The ERPs were recorded for approximately 1000 msec, and peaks were recorded within three different time windows: 52.5 to 170.0 msec (N100), 172.5 to 285.0 msec (P200) and 290.0 to 580.0 msec (P300). Two of the amplitude measures, P200 and P300, were referenced to N100 resulting in peak-to-peak amplitude measures of N100P200 and N100P300. Peak latencies corresponding to the N100, P200, and P300 amplitudes were also computed.; Seven young female and seven young male adults listened to two identical presentations of ten randomized recordings of each of the ten stimulus sentences (200 total sentences). Five of the sentences were meaningful while the other five were anomalous. Each sentence had a cognate sentence which differed in the final (Key) word or element.; Subsequent analyses of variance and planned comparison testing indicated that females manifested significantly more positive N100P300 amplitudes than males at Cz and P3. Semantically inappropriate sentences were generally significantly more negative (N100) or more positive (N100P200, N100P300) than the semantically appropriate sentences. Latencies were generally shorter for the semantically inappropriate sentences, however, these differences were not as pronounced nor as consistent as the amplitude differences. Although there were no significant differences between presentations, ERPs for the first presentation generally manifested more positive waveforms than did the second presentation.