University of Newcastle.
Biol Psychol. 2021 Sep;164:108161. doi: 10.1016/j.biopsycho.2021.108161. Epub 2021 Jul 30.
Mismatch Negativity (MMN) to pattern deviations reveals exquisite pattern detection ability in the brain. MMN amplitude is proposed to be precision-weighted, being inversely proportional to variability within a patterned sound sequence. Two experiments were conducted to determine whether pattern variability, shown to influence MMN to simple pattern deviance, also extends to MMN elicited to abstract pattern deviants. Participants were presented with 3-tone triplet sequences that were defined by regular frequency ascendance with adjacent (A<B<C) or non-adjacent (A<C) dependency. The triplets were defined by an abstract pattern in that the starting frequency of A roamed randomly between 500-3700 Hz. Using variants of these sequences over two studies the results show that MMN was elicited to rare A > C deviants for adjacent and non-adjacent dependencies, was smaller for the latter, was impervious to variance in tone loudness, but showed prolonged sensitivity to the level of variability at sequence onset.
失匹配负波（MMN）对模式偏差的反应揭示了大脑中对模式的精确检测能力。有人提出，MMN 幅度是经过精确加权的，与模式声音序列内的可变性成反比。进行了两项实验，以确定模式可变性是否会影响对简单模式偏差的 MMN，以及是否会扩展到对抽象模式偏差引发的 MMN。参与者被呈现由三音三连音序列组成的声音，这些序列由规则的频率上升定义，相邻（A<B<C）或不相邻（A<C）。三连音序列的起始频率在 500-3700Hz 之间随机漫游，这使得它们在抽象层面上具有模式特征。通过在两项研究中使用这些序列的变体，结果表明，对相邻和不相邻依赖关系的罕见 A>C 偏差会引发 MMN，后者的 MMN 幅度较小，对音调响度的变化不敏感，但对序列起始时的可变性水平保持敏感。
