Musical imagery is the voluntary internal hearing of music in the mind without the need for physical action or external stimulation. Numerous studies have already revealed brain areas activated during imagery. However, it remains unclear to what extent imagined music responses preserve the detailed temporal dynamics of the acoustic stimulus envelope and, crucially, whether melodic expectations play any role in modulating responses to imagined music, as they prominently do during listening. These modulations are important as they reflect aspects of the human musical experience, such as its acquisition, engagement, and enjoyment. This study explored the nature of these modulations in imagined music based on EEG recordings from 21 professional musicians (6 females and 15 males). Regression analyses were conducted to demonstrate that imagined neural signals can be predicted accurately, similarly to the listening task, and were sufficiently robust to allow for accurate identification of the imagined musical piece from the EEG. In doing so, our results indicate that imagery and listening tasks elicited an overlapping but distinctive topography of neural responses to sound acoustics, which is in line with previous fMRI literature. Melodic expectation, however, evoked very similar frontal spatial activation in both conditions, suggesting that they are supported by the same underlying mechanisms. Finally, neural responses induced by imagery exhibited a specific transformation from the listening condition, which primarily included a relative delay and a polarity inversion of the response. This transformation demonstrates the top-down predictive nature of the expectation mechanisms arising during both listening and imagery.

SIGNIFICANCE STATEMENT It is well known that the human brain is activated during musical imagery: the act of voluntarily hearing music in our mind without external stimulation. It is unclear, however, what the temporal dynamics of this activation are, as well as what musical features are precisely encoded in the neural signals. This study uses an experimental paradigm with high temporal precision to record and analyze the cortical activity during musical imagery. This study reveals that neural signals encode music acoustics and melodic expectations during both listening and imagery. Crucially, it is also found that a simple mapping based on a time-shift and a polarity inversion could robustly describe the relationship between listening and imagery signals.

音乐意象是在不需要身体动作或外部刺激的情况下在头脑中自愿内部听到音乐。许多研究已经揭示了在成像过程中激活的大脑区域。然而，目前尚不清楚想象中的音乐反应在多大程度上保留了声学刺激包络的详细时间动态，并且至关重要的是，旋律期望是否在调节对想象中音乐的反应中发挥任何作用，正如它们在聆听过程中所做的那样。这些调制很重要，因为它们反映了人类音乐体验的各个方面，例如获得、参与和享受。本研究基于 21 位专业音乐家（6 位女性和 15 位男性）的脑电图记录，探索了想象音乐中这些调制的性质。进行回归分析以证明可以准确预测想象的神经信号，类似于听力任务，并且足够稳健，可以从 EEG 中准确识别想象的音乐作品。在这样做时，我们的结果表明，图像和听力任务引发了对声音声学的神经反应的重叠但独特的地形，这与之前的 fMRI 文献一致。然而，旋律期望在两种情况下都引起了非常相似的额叶空间激活，表明它们受到相同的潜在机制的支持。最后，由图像引起的神经反应表现出与听力条件的特定转变，主要包括反应的相对延迟和极性反转。

意义陈述众所周知，人类大脑在音乐想象中被激活：在没有外部刺激的情况下自愿在我们的脑海中聆听音乐的行为。然而，目前尚不清楚这种激活的时间动态是什么，以及神经信号中精确编码了哪些音乐特征。本研究使用具有高时间精度的实验范式来记录和分析音乐意象期间的皮层活动。这项研究表明，神经信号在聆听和想象过程中对音乐声学和旋律期望进行编码。至关重要的是，还发现基于时移和极性反转的简单映射可以稳健地描述听力和图像信号之间的关系。