McDermott Timothy J, Wiesman Alex I, Proskovec Amy L, Heinrichs-Graham Elizabeth, Wilson Tony W
Center for Magnetoencephalography, University of Nebraska Medical Center (UNMC), Omaha, NE, USA.
Center for Magnetoencephalography, University of Nebraska Medical Center (UNMC), Omaha, NE, USA; Department of Neurological Sciences, UNMC, Omaha, NE, USA.
Neuroimage. 2017 Aug 1;156:277-285. doi: 10.1016/j.neuroimage.2017.05.014. Epub 2017 May 10.
The flanker task is a test of visual selective attention that has been widely used to probe error monitoring, response conflict, and related constructs. However, to date, few studies have focused on the selective attention component of this task and imaged the underlying oscillatory dynamics serving task performance. In this study, 21 healthy adults successfully completed an arrow-based version of the Eriksen flanker task during magnetoencephalography (MEG). All MEG data were pre-processed and transformed into the time-frequency domain. Significant oscillatory brain responses were imaged using a beamforming approach, and voxel time series were extracted from the peak responses to identify the temporal dynamics. Across both congruent and incongruent flanker conditions, our results indicated robust decreases in alpha (9-12Hz) activity in medial and lateral occipital regions, bilateral parietal cortices, and cerebellar areas during task performance. In parallel, increases in theta (3-7Hz) oscillatory activity were detected in dorsal and ventral frontal regions, and the anterior cingulate. As per conditional effects, stronger alpha responses (i.e., greater desynchronization) were observed in parietal, occipital, and cerebellar cortices during incongruent relative to congruent trials, whereas the opposite pattern emerged for theta responses (i.e., synchronization) in the anterior cingulate, left dorsolateral prefrontal, and ventral prefrontal cortices. Interestingly, the peak latency of theta responses in these latter brain regions was significantly correlated with reaction time, and may partially explain the amplitude difference observed between congruent and incongruent trials. Lastly, whole-brain exploratory analyses implicated the frontal eye fields, right temporoparietal junction, and premotor cortices. These findings suggest that regions of both the dorsal and ventral attention networks contribute to visual selective attention processes during incongruent trials, and that such differential processes are transient and fully completed shortly after the behavioral response in most trials.
侧翼任务是一种视觉选择性注意测试，已被广泛用于探究错误监测、反应冲突及相关结构。然而，迄今为止，很少有研究关注该任务的选择性注意成分，也没有对支持任务表现的潜在振荡动力学进行成像研究。在本研究中，21名健康成年人在脑磁图（MEG）记录期间成功完成了基于箭头的埃里克森侧翼任务。所有MEG数据均经过预处理并转换到时间-频率域。使用波束形成方法对显著的振荡脑反应进行成像，并从峰值反应中提取体素时间序列以确定时间动态。在一致和不一致的侧翼条件下，我们的结果表明，在任务执行期间，枕叶内侧和外侧区域、双侧顶叶皮质以及小脑区域的α（9-12Hz）活动显著降低。同时，在背侧和腹侧额叶区域以及前扣带回中检测到θ（3-7Hz）振荡活动增加。根据条件效应，在不一致试验相对于一致试验期间，顶叶、枕叶和小脑皮质中观察到更强的α反应（即更大的去同步化），而在前扣带回、左侧背外侧前额叶和腹侧前额叶皮质中，θ反应（即同步化）则呈现相反的模式。有趣的是，这些脑区中θ反应的峰值潜伏期与反应时间显著相关，并且可能部分解释了一致和不一致试验之间观察到的振幅差异。最后，全脑探索性分析涉及额叶眼区、右侧颞顶联合区和运动前皮质。这些发现表明，在不一致试验期间，背侧和腹侧注意网络的区域都有助于视觉选择性注意过程，并且这种差异过程是短暂的，在大多数试验中行为反应后不久就会完全完成。
