Repp Bruno H, Keller Peter E, Jacoby Nori
Haskins Laboratories, New Haven, CT, USA.
Acta Psychol (Amst). 2012 Feb;139(2):281-90. doi: 10.1016/j.actpsy.2011.11.002. Epub 2012 Jan 4.
Tapping in synchrony with a metronome requires phase error correction, a process often described by a single-parameter autoregressive model. The parameter (α) is a measure of sensorimotor coupling strength. This study compares α estimates obtained from three experimental paradigms: synchronization with (1) a perfectly regular metronome (RM), (2) a perturbed metronome containing phase shifts (PS), and (3) an "adaptively timed" metronome (AT). Musically trained participants performed in each paradigm at four tempi, with baseline interval durations ranging from 400 to 1300 ms. Two estimation methods were applied to each data set. Results showed that all α estimates increased with interval duration. However, the PS paradigm yielded much larger α values than did the AT paradigm, with those from the RM paradigm falling in between. Positional analysis of the PS data revealed that α increased immediately following a phase shift and then decreased sharply. Unexpectedly, all PS α estimates were uncorrelated with the RM and AT estimates, which were strongly correlated. These results suggest that abruptly perturbed sequences engage a different mechanism of phase correction than do regular or continuously modulated sequences.
与节拍器同步敲击需要相位误差校正，这一过程通常由单参数自回归模型来描述。参数（α）是感觉运动耦合强度的一种度量。本研究比较了从三种实验范式中获得的α估计值：与（1）完全规则的节拍器（RM）同步、（2）包含相位偏移的受扰节拍器（PS）同步以及（3）“自适应定时”节拍器（AT）同步。接受过音乐训练的参与者在每种范式下以四种节奏进行实验，基线间隔时长范围为400至1300毫秒。对每个数据集应用了两种估计方法。结果表明，所有α估计值均随间隔时长增加。然而，PS范式产生的α值比AT范式大得多，RM范式产生的α值则介于两者之间。对PS数据的位置分析表明，α在相位偏移后立即增加，然后急剧下降。出乎意料的是，所有PS的α估计值与RM和AT的估计值均不相关，而RM和AT的估计值之间则高度相关。这些结果表明，与规则序列或连续调制序列相比，突然受扰的序列采用了不同的相位校正机制。
