Merchant Hugo, Averbeck Bruno B
Instituto de Neurobiología, UNAM, Campus Juriquilla, Boulevard Juriquilla No. 3001 Querétaro, Qro, 76230 México, and
Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-4415.
J Neurosci. 2017 Apr 26;37(17):4552-4564. doi: 10.1523/JNEUROSCI.0367-17.2017. Epub 2017 Mar 23.
The neural underpinnings of rhythmic behavior, including music and dance, have been studied using the synchronization-continuation task (SCT), where subjects initially tap in synchrony with an isochronous metronome and then keep tapping at a similar rate via an internal beat mechanism. Here, we provide behavioral and neural evidence that supports a resetting drift-diffusion model (DDM) during SCT. Behaviorally, we show the model replicates the linear relation between the mean and standard-deviation of the intervals produced by monkeys in SCT. We then show that neural populations in the medial premotor cortex (MPC) contain an accurate trial-by-trial representation of elapsed-time between taps. Interestingly, the autocorrelation structure of the elapsed-time representation is consistent with a DDM. These results indicate that MPC has an orderly representation of time with features characteristic of concatenated DDMs and that this population signal can be used to orchestrate the rhythmic structure of the internally timed elements of SCT. The present study used behavioral data, ensemble recordings from medial premotor cortex (MPC) in macaque monkeys, and computational modeling, to establish evidence in favor of a class of drift-diffusion models of rhythmic timing during a synchronization-continuation tapping task (SCT). The linear relation between the mean and standard-deviation of the intervals produced by monkeys in SCT is replicated by the model. Populations of MPC cells faithfully represent the elapsed time between taps, and there is significant trial-by-trial relation between decoded times and the timing behavior of the monkeys. Notably, the neural decoding properties, including its autocorrelation structure are consistent with a set of drift-diffusion models that are arranged sequentially and that are resetting in each SCT tap.
包括音乐和舞蹈在内的节奏行为的神经基础，已通过同步 - 延续任务（SCT）进行了研究。在该任务中，受试者最初与等时节拍器同步敲击，然后通过内部节拍机制以相似的速率继续敲击。在此，我们提供行为和神经方面的证据，支持在SCT期间的一种重置漂移扩散模型（DDM）。在行为上，我们表明该模型复制了猴子在SCT中产生的间隔的均值与标准差之间的线性关系。然后我们表明，内侧运动前皮层（MPC）中的神经群体包含每次敲击之间经过时间的准确逐次试验表征。有趣的是，经过时间表征的自相关结构与DDM一致。这些结果表明，MPC具有时间的有序表征，具有串联DDM的特征，并且该群体信号可用于编排SCT内部定时元素的节奏结构。本研究使用行为数据、猕猴内侧运动前皮层（MPC）的群体记录以及计算建模，以建立支持同步 - 延续敲击任务（SCT）期间一类节奏定时漂移扩散模型的证据。该模型复制了猴子在SCT中产生的间隔的均值与标准差之间的线性关系。MPC细胞群体忠实地代表了敲击之间的经过时间，并且解码时间与猴子的定时行为之间存在显著的逐次试验关系。值得注意的是，神经解码特性，包括其自相关结构，与一组按顺序排列且在每个SCT敲击时重置的漂移扩散模型一致。
