Mismatch Negativity in Normal Young People

WANG Hongnan; WU Wei; HAN Haolun; LI Baowei; WANG Gang; SUN Zhezhe; MENG Lingzhao; WANG Lei; CHEN Yanfang; DING Ruiying; SUN Jianzhi

doi:10.3969/j.issn.1672-2922.2014.02.13

Abstract：Objective To investigate the characteristics of mismatch negativity (MMN) in normal young people, and ef-fects of status of attention on MMN results. Methods MMN tests were performed on 12 young females (age 29-31years, aver-age 30.08 years) and 18 young males (age 27-34 years, average 30.22 years). In all cases, acoustic brainstem responses (ABR) were tested first so as to identify the ABR threshold. MMN were tested under the status of reading or concentrating. The odd-ball model was used in MMN testing, with brief pure tones used as the stimulus. The deviation frequency was 2000 Hz with a rate of 20%, and the standard frequency was 1000 Hz with a rate of 80%. The stimulus was delivered at 50 dB above the ABR threshold at a rate of 1.1/sec. The latency and amplitude of MMN in each group and under different attention status were analyzed. Results In all cases, ABR thresholds were≤25 dB nHL, and MMN was successfully induced. In the female group, the latency of MMN was 159.57 ± 20.64 ms with an average amplitude of 3.82 ± 1.38 uV when reading, and 155.96 ± 17.51 ms with an average amplitude of 4.28±1.89 uV when concentrating, showing no statistically significant difference on paired-t test. In the male group, the latency of MMN was 150.48 ± 19.57 ms with an average amplitude of 3.75 ± 1.27 uV when reading, and 144.81±15.42 ms with an average amplitude of 3.99±1.34 uV when concentrating, again showing no statistically significant dif-ference by paired t-test. By independent t-test, the latency and the amplitude differences were not statistically significant be-tween the female and male groups under either attention status. Conclusion MMN can be easily induced in normal young peo-ple, with no significant differences in latency or amplitude between males and females. Status of attention does not affect the re-sults of MMN test.