Executive functions and prefrontal cortex: a matter of persistence?
Executive functions and prefrontal cortex: a matter of persistence?
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DOI：
10.3389/fnsys.2011.00003
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发表时间：
2011
影响因子：
3
通讯作者：
Turkheimer FE
中科院分区：
文献类型：
--
作者：
Ball G;Stokes PR;Rhodes RA;Bose SK;Rezek I;Wink AM;Lord LD;Mehta MA;Grasby PM;Turkheimer FE
执行功能被认为源自额叶皮层网络的动态。我们检查了前额皮质 (PFC) 内功能性 MRI (fMRI) 测量的血氧水平依赖性时间序列的动态特性，以检验以下假设：暂时持续的神经活动是执行功能的三项任务表现的基础。确定了信号持久性的数值估计，即赫斯特指数，假定代表皮质网络的相干放电，并将其与任务表现相关联。研究表明，侧前额皮质持续性的增加与 n-back 任务中表现的提高相关。相反，我们观察到在执行/不执行任务期间，持久性与不断增加的佣金错误之间存在相关性（表明未能抑制优势响应）。我们认为 PFC 内的持久性反映了动态网络的形成，这些发现强调了功能磁共振成像时间序列频率分析在执行功能研究中的重要性。
Executive function is thought to originates from the dynamics of frontal cortical networks. We examined the dynamic properties of the blood oxygen level dependent time-series measured with functional MRI (fMRI) within the prefrontal cortex (PFC) to test the hypothesis that temporally persistent neural activity underlies performance in three tasks of executive function. A numerical estimate of signal persistence, the Hurst exponent, postulated to represent the coherent firing of cortical networks, was determined and correlated with task performance. Increasing persistence in the lateral PFC was shown to correlate with improved performance during an n-back task. Conversely, we observed a correlation between persistence and increasing commission error – indicating a failure to inhibit a prepotent response – during a Go/No-Go task. We propose that persistence within the PFC reflects dynamic network formation and these findings underline the importance of frequency analysis of fMRI time-series in the study of executive functions.