Institute of Psychology-Wilhelm Wundt, Leipzig University, Leipzig, Germany.
PLoS One. 2021 Feb 25;16(2):e0247495. doi: 10.1371/journal.pone.0247495. eCollection 2021.
The human auditory system often relies on relative pitch information to extract and identify auditory objects; such as when the same melody is played in different keys. The current study investigated the mental chronometry underlying the active discrimination of unfamiliar melodic six-tone patterns by measuring behavioural performance and event-related potentials (ERPs). In a roving standard paradigm, such patterns were either repeated identically within a stimulus train, carrying absolute frequency information about the pattern, or shifted in pitch (transposed) between repetitions, so only relative pitch information was available to extract the pattern identity. Results showed that participants were able to use relative pitch to detect when a new melodic pattern occurred. Though in the absence of absolute pitch sensitivity significantly decreased and behavioural reaction time to pattern changes increased. Mismatch-Negativity (MMN), an ERP indicator of auditory deviance detection, was elicited at approximately 206 ms after stimulus onset at frontocentral electrodes, even when only relative pitch was available to inform pattern discrimination. A P3a was elicited in both conditions, comparable in amplitude and latency. Increased latencies but no differences in amplitudes of N2b, and P3b suggest that processing at higher levels is affected when, in the absence of absolute pitch cues, relative pitch has to be extracted to inform pattern discrimination. Interestingly, the response delay of approximately 70 ms on the behavioural level, already fully manifests at the level of N2b. This is in accordance with recent findings on implicit auditory learning processes and suggests that in the absence of absolute pitch cues a slowing of target selection rather than a slowing of the auditory pattern change detection process causes the deterioration in behavioural performance.
人类听觉系统通常依赖相对音高信息来提取和识别听觉对象；例如，当同一旋律以不同的调式演奏时。本研究通过测量行为表现和事件相关电位（ERP），探讨了在主动辨别不熟悉的旋律六音模式时的心理时间测定法。在一个游动标准范式中，这些模式要么在刺激序列中重复相同，携带模式的绝对频率信息，要么在重复之间改变音高（转调），因此只有相对音高信息可用于提取模式身份。结果表明，参与者能够使用相对音高来检测新旋律模式何时出现。尽管在没有绝对音高敏感度的情况下，模式识别的行为反应时间显著增加，且敏感度显著降低。在额中央电极处，大约在刺激开始后 206 毫秒就会产生失匹配负波（MMN），这是一种听觉偏差检测的 ERP 指标，即使只有相对音高可用于告知模式辨别。在两种情况下都诱发出 P3a，其幅度和潜伏期相当。N2b 的潜伏期增加，但幅度没有差异，P3b 表明，当不存在绝对音高线索时，必须提取相对音高来告知模式辨别，这会影响到更高层次的处理。有趣的是，在行为水平上大约 70 毫秒的反应延迟，已经在 N2b 水平上完全表现出来。这与最近关于内隐听觉学习过程的发现一致，表明在不存在绝对音高线索的情况下，目标选择的速度减慢而不是听觉模式变化检测过程的速度减慢导致行为表现恶化。
