失匹配负波时长范式的波幅与刺激差异的关系及其临床价值

Relationship between the amplitude of duration mismatch negativity and the stimuli deviation and its clinical significance

目的探讨失匹配负波(mismatch negativity,MMN)时长范式的波幅与刺激差异的关系,探索具有最大波幅的偏差刺激,为推进MMN的临床应用提供理论依据。方法本研究采用被试内设计,随机选取28名大学生,通过oddball范式诱发MMN。标准刺激时长为50 ms,偏差刺激时长分别为100 ms,200 ms,250 ms。统计方法为重复测量方差分析,统计指标为Fz、FCz、Cz点的平均波幅(130-300 ms)和潜伏期。结果①当偏差刺激为200 ms和250 ms时,波幅和潜伏期差异均无统计学意义(P>0.05),但与100 ms时相比,二者的波幅增大,潜伏期延迟,差异均有统计学意义(P<0.05)。②Fz点和FCz点的波幅差异无统计学意义(P>0.05),但二者均大于Cz,差异有统计学意义(P<0.05)。③Fz、FCz和Cz点的潜伏期差异无统计学意义(P>0.05)。结论①当偏差刺激为200 ms时,波幅达到最大且时长相对较短,可能是时长范式的最佳参数设置。②Fz和FCz点的波幅比Cz更大,可作为MMN的主要电极。

Objective To explore the relationship between the amplitude of duration mismatch negativity(MMN)and the stimuli deviation,find out the deviant stimulus with the greatest amplitude,and lay a theoretical foundation for advancing the clinical application of MMN.Methods The within-subjects design was used in this study and 28 college students were selected randomly.MMN was induced through oddball paradigm in which the duration of the standard stimulus was 50 ms,and the duration of the deviant stimuli were 100 ms,200 ms,and 250 ms respectively.The average amplitude(130-300 ms)and latency of Fz,FCz,Cz were analyzed with repeated measurement analysis of variance.Results①There was no significant difference between 200 ms and 250 ms in amplitude and latency(P>0.05),but compared with 100 ms,the amplitude and latency of 200 ms and 250 ms were both increased significantly(P<0.05).②There was no significant difference in the amplitude between Fz and FCz(P>0.05),but the amplitude of the two deviants were both larger than that of Cz(P<0.05).③There was no significant difference in the latency of Fz,FCz and Cz(P>0.05).Conclusion①When the deviant stimulus is 200 ms,the amplitude of MMN reaches the maximum and the duration of the deviant stimulus is relatively short,which may be the best parameter setting of the duration paradigm.②Fz and FCz can be used as the main electrode of MMN because of their larger amplitude than Cz.