In typical listeners, the perceptual salience of a surprising auditory event depends on the uncertainty of its context. For example, in melodies, pitch deviants are more easily detected and generate larger neural responses when the context is highly predictable than when it is less so. However, it is not known whether amusic listeners with abnormal pitch processing are sensitive to the degree of uncertainty of pitch sequences and, if so, whether they are to a different extent than typical non-musician listeners. To answer this question, we manipulated the uncertainty of short melodies while participants with and without congenital amusia underwent EEG recordings in a passive listening task. Uncertainty was manipulated by presenting melodies with different levels of complexity and familiarity, under the assumption that simpler and more familiar patterns would enhance pitch predictability. We recorded mismatch negativity (MMN) responses to pitch, intensity, timbre, location, and rhythm deviants as a measure of auditory surprise. In both participant groups, we observed reduced MMN amplitudes and longer peak latencies for all sound features with increasing levels of complexity, and putative familiarity effects only for intensity deviants. No significant group-by-complexity or group-by-familiarity interactions were detected. However, in contrast to previous studies, pitch MMN responses in amusics were disrupted in high complexity and unfamiliar melodies. The present results thus indicate that amusics are sensitive to the uncertainty of melodic sequences and that preattentive auditory change detection is greatly spared in this population across sound features and levels of predictability. However, our findings also hint at pitch-specific impairments in this population when uncertainty is high, thus suggesting that pitch processing under high uncertainty conditions requires an intact frontotemporal loop.

在典型的听众中，令人惊讶的听觉事件的感知显着性取决于其上下文的不确定性。例如，在旋律中，当上下文高度可预测时比在可预测性较低时更容易检测到音高偏差并产生更大的神经反应。然而，不知道具有异常音高处理的音乐听众是否对音高序列的不确定程度敏感，如果是，他们是否与典型的非音乐家听众的程度不同。为了回答这个问题，我们操纵了短旋律的不确定性，而有和没有先天性失忆症的参与者在被动聆听任务中接受了脑电图记录。通过呈现具有不同复杂程度和熟悉程度的旋律来操纵不确定性，假设更简单和更熟悉的模式会增强音高可预测性。我们记录了对音高、强度、音色、位置和节奏异常的失配负性 (MMN) 响应，作为听觉惊喜的衡量标准。在这两个参与者组中，我们观察到所有声音特征的 MMN 振幅降低，峰值延迟延长，复杂程度不断提高，并且推定的熟悉效应仅适用于强度偏差。没有检测到显着的逐组复杂性或逐组熟悉的相互作用。然而，与之前的研究相反，在高复杂度和不熟悉的旋律中，音乐中的音调 MMN 反应被打乱了。因此，目前的结果表明 amusics 对旋律序列的不确定性很敏感，并且在这个人群中，在声音特征和可预测性水平上，预注意听觉变化检测在很大程度上得以幸免。然而，我们的研究结果还暗示，当不确定性很高时，这一群体中的音高特定损伤，因此表明高不确定性条件下的音高处理需要完整的额颞循环。