Department of Psychology, University of Minnesota, Minneapolis, MN, USA.
Cortex. 2018 Jun;103:164-178. doi: 10.1016/j.cortex.2018.03.012. Epub 2018 Mar 23.
Congenital amusia is currently thought to be a life-long neurogenetic disorder in music perception, impervious to training in pitch or melody discrimination. This study provides an explicit test of whether amusic deficits can be reduced with training. Twenty amusics and 20 matched controls participated in four sessions of psychophysical training involving either pure-tone (500 Hz) pitch discrimination or a control task of lateralization (interaural level differences for bandpass white noise). Pure-tone pitch discrimination at low, medium, and high frequencies (500, 2000, and 8000 Hz) was measured before and after training (pretest and posttest) to determine the specificity of learning. Melody discrimination was also assessed before and after training using the full Montreal Battery of Evaluation of Amusia, the most widely used standardized test to diagnose amusia. Amusics performed more poorly than controls in pitch but not localization discrimination, but both groups improved with practice on the trained stimuli. Learning was broad, occurring across all three frequencies and melody discrimination for all groups, including those who trained on the non-pitch control task. Following training, 11 of 20 amusics no longer met the global diagnostic criteria for amusia. A separate group of untrained controls (n = 20), who also completed melody discrimination and pretest, improved by an equal amount as trained controls on all measures, suggesting that the bulk of learning for the control group occurred very rapidly from the pretest. Thirty-one trained participants (13 amusics) returned one year later to assess long-term maintenance of pitch and melody discrimination. On average, there was no change in performance between posttest and one-year follow-up, demonstrating that improvements on pitch- and melody-related tasks in amusics and controls can be maintained. The findings indicate that amusia is not always a life-long deficit when using the current standard diagnostic criteria.
先天性失乐症目前被认为是一种终身性的音乐感知神经遗传障碍，对音高或旋律辨别训练无反应。本研究对失乐症患者的缺陷是否可以通过训练得到改善进行了明确的测试。20 名失乐症患者和 20 名匹配的对照组参与者参加了四节心理物理训练课程，涉及纯音（500Hz）音高辨别或控制任务（带通白噪声的两耳间水平差异）。在训练前后（预测试和后测试）测量了低、中、高频（500、2000 和 8000Hz）的纯音音高辨别，以确定学习的特异性。在训练前后，还使用最广泛用于诊断失乐症的标准化测试——蒙特利尔音乐障碍评估量表，评估了旋律辨别能力。失乐症患者在音高辨别而非定位辨别方面的表现均不如对照组，但两组在接受训练刺激的练习后都有所提高。学习是广泛的，所有三组频率和旋律辨别能力的所有组，包括接受非音高控制任务训练的组，都有提高。训练后，20 名失乐症患者中有 11 名不再符合失乐症的全球诊断标准。一组未接受训练的对照组（n=20），他们也完成了旋律辨别和预测试，在所有测试中与训练对照组的提高幅度相同，这表明对照组的大部分学习是在预测试后非常迅速地进行的。31 名接受过训练的参与者（13 名失乐症患者）一年后返回以评估音高和旋律辨别能力的长期保持情况。平均而言，后测试和一年后随访之间的表现没有变化，这表明失乐症患者和对照组在音高和旋律相关任务上的提高可以保持。这些发现表明，当使用当前的标准诊断标准时，失乐症并不总是终身缺陷。
