Center for Music in the Brain, Aarhus University and The Royal Academy of Music, Denmark.
The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Australia.
Cortex. 2019 Nov;120:181-200. doi: 10.1016/j.cortex.2019.06.010. Epub 2019 Jun 28.
Theories of predictive processing propose that prediction error responses are modulated by the certainty of the predictive model or precision. While there is some evidence for this phenomenon in the visual and, to a lesser extent, the auditory modality, little is known about whether it operates in the complex auditory contexts of daily life. Here, we examined how prediction error responses behave in a more complex and ecologically valid auditory context than those typically studied. We created musical tone sequences with different degrees of pitch uncertainty to manipulate the precision of participants' auditory expectations. Magnetoencephalography was used to measure the magnetic counterpart of the mismatch negativity (MMNm) as a neural marker of prediction error in a multi-feature paradigm. Pitch, slide, intensity and timbre deviants were included. We compared high-entropy stimuli, consisting of a set of non-repetitive melodies, with low-entropy stimuli consisting of a simple, repetitive pitch pattern. Pitch entropy was quantitatively assessed with an information-theoretic model of auditory expectation. We found a reduction in pitch and slide MMNm amplitudes in the high-entropy as compared to the low-entropy context. No significant differences were found for intensity and timbre MMNm amplitudes. Furthermore, in a separate behavioral experiment investigating the detection of pitch deviants, similar decreases were found for accuracy measures in response to more fine-grained increases in pitch entropy. Our results are consistent with a precision modulation of auditory prediction error in a musical context, and suggest that this effect is specific to features that depend on the manipulated dimension-pitch information, in this case.
预测加工理论提出，预测误差反应受到预测模型或精度的确定性的调节。虽然在视觉和听觉模式中都有一些关于这种现象的证据，但其在日常生活中复杂的听觉环境中是否存在，人们知之甚少。在这里，我们研究了预测误差反应在比通常研究更复杂和更具生态效度的听觉环境中的表现。我们创建了具有不同音高不确定性程度的音乐音调序列，以操纵参与者听觉期望的精度。使用脑磁图来测量与预测误差相关的失匹配负波（MMNm）的磁对应物，作为多特征范式中的神经标记。包括音高、滑音、强度和音色偏差。我们将由一组非重复旋律组成的高熵刺激与由简单、重复音高模式组成的低熵刺激进行比较。使用听觉期望的信息论模型对音高熵进行定量评估。与低熵环境相比，我们发现高熵环境中的音高和滑音 MMNm 振幅减小。强度和音色 MMNm 振幅没有显著差异。此外，在一项单独的行为实验中，我们研究了对音高偏差的检测，发现对于更精细的音高熵增加，响应的准确性测量值也出现了类似的降低。我们的结果与音乐背景下听觉预测误差的精度调节一致，并表明这种效应特定于依赖于所操纵维度（在这种情况下为音高信息）的特征。
