Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
Aging Research Centre - Newfoundland and Labrador, Grenfell Campus, Memorial University, Corner Brook, Canada.
Int J Dev Neurosci. 2022 Jun;82(4):314-330. doi: 10.1002/jdn.10181. Epub 2022 Apr 4.
Amusia is defined as a difficulty processing the tonal pitch structure of music such that an individual cannot tell the difference between notes that are in-key and out-of-key. A fine-grained pitch discrimination deficit is often observed in people with amusia. It is possible that an intervention, early in development, could mitigate amusia; however, one challenge identifying amusia early in development is that identifying in- and out-of-key notes is a metacognitive task. Given the common co-occurrence of difficulties with pitch discrimination, it would be easier to identify amusia in developing children by using a pitch change detection task. The goal of this study was to explore the behavioural and neurophysiological profiles of adolescents with poor pitch processing (Poor PP) abilities compared with those with normal pitch processing (Normal PP) abilities. Neurophysiologically, the Poor PPs exhibited a similar event-related potential (ERP) profile to adult amusics during both acoustic and musical pitch discrimination tasks. That is, early ERPs (ERAN, MMN) were similar in Poor PPs compared with Normal PPs, whereas late positivities (P300, P600) were absent in Poor PPs, but present in Normal PPs. At the same time, behavioural data revealed a double dissociation between the abilities to detect a pitch deviant in acoustic and musical context, suggesting that about a third of the children would be missed by selecting a fine-grained acoustic pitch discrimination task to identify the presence of amusia in early childhood.
失歌症被定义为处理音乐音高结构的困难，以至于个体无法分辨出音准和音准外的音符。失歌症患者通常存在精细音高辨别缺陷。早期干预可能减轻失歌症；然而，早期识别失歌症的一个挑战是，识别音准和音准外的音符是一种元认知任务。鉴于音高辨别困难的共同发生，使用音高变化检测任务更容易识别发展中的儿童的失歌症。本研究的目的是探索与具有正常音高处理能力（正常 PP）的青少年相比，音高处理能力较差（较差 PP）的青少年的行为和神经生理特征。神经生理学上，较差的 PPs 在声学和音乐音高辨别任务中表现出与成人失歌症相似的事件相关电位（ERP）模式。也就是说，较差的 PPs 的早期 ERP（ERAN、MMN）与正常的 PPs 相似，而较差的 PPs 中没有晚期正波（P300、P600），但在正常的 PPs 中存在。同时，行为数据显示在声学和音乐语境中检测音高偏差的能力存在双重分离，这表明大约三分之一的儿童会错过选择精细的声学音高辨别任务来识别早期儿童失歌症的存在。
