The present study tested two assumptions concerning the auditory processing of microtiming in musical grooves (i.e., repeating, movement-inducing rhythmic patterns): 1) Microtiming challenges the listener9s internal framework of timing regularities, or meter, and demands cognitive effort. 2) Microtiming promotes a “groove” experience—a pleasant sense of wanting to move along with the music. Using professional jazz musicians and nonmusicians as participants, we hypothesized that microtiming asynchronies between bass and drums (varying from −80 to 80 ms) were related to a) an increase in “mental effort” (as indexed by pupillometry), and b) a decrease in the quality of sensorimotor synchronization (as indexed by reduced finger tapping stability). We found bass/drums-microtiming asynchronies to be positively related to pupil dilation and negatively related to tapping stability. In contrast, we found that steady timekeeping (presence of eighth note hi-hat in the grooves) decreased pupil size and increased tapping performance, though there were no conclusive differences in pupil response between musicians and nonmusicians. However, jazz musicians consistently tapped with higher stability than nonmusicians, reflecting an effect of rhythmic expertise. Except for the condition most closely resembling real music, participants preferred the on-the-grid grooves to displacements in microtiming and bass-succeeding-drums-conditions were preferred over the reverse.

中文翻译：

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微定时和精神努力

本研究测试了关于音乐凹槽中微定时的听觉处理（即重复，诱发运动的节奏模式）的两个假设：1）微定时挑战了收听者的定时规律或音调的内部框架，并需要认知努力。2）Microtiming促进了“凹槽”体验—一种希望随音乐一起移动的愉悦感。以专业爵士乐音乐家和非音乐家为参与者，我们假设低音和鼓之间的微音调非同步性（从-80到80毫秒不等）与a）“心理努力”的增加（按瞳孔法确定）有关，并且b）a感觉运动同步的质量下降（以降低的手指敲击稳定性为指标）。我们发现低音/鼓微调异步与瞳孔扩张正相关，与拍打稳定性负相关。相比之下，我们发现稳定的计时（凹槽中有八音高音）减少了瞳孔大小，提高了拍打性能，尽管音乐家和非音乐家在瞳孔反应方面没有确凿的差异。但是，爵士乐手始终具有比非音乐家更高的稳定性，这反映出节奏专业知识的效果。除了最接近真实音乐的条件之外，与之相反，参与者更喜欢使用网格上的凹槽而不是微定时中的位移，并且更喜欢低音成功的鼓条件。我们发现稳定的计时（凹槽中有八音高音）减少了瞳孔大小，提高了拍打性能，尽管音乐家和非音乐家在瞳孔反应方面没有确凿的差异。但是，爵士乐手始终具有比非音乐家更高的稳定性，这反映出节奏专业知识的效果。除了最接近真实音乐的条件之外，与之相反，参与者更喜欢使用网格上的凹槽而不是微定时中的位移，并且更喜欢低音成功的鼓条件。我们发现稳定的计时（凹槽中有八音高音）减少了瞳孔大小，提高了拍打性能，尽管音乐家和非音乐家在瞳孔反应方面没有确凿的差异。但是，爵士乐手始终具有比非音乐家更高的稳定性，这反映出节奏专业知识的效果。除了最接近真实音乐的条件之外，与之相反，参与者更喜欢使用网格上的凹槽而不是微定时中的位移，并且更喜欢低音成功的鼓条件。