Predicting Reaction Time from the Neural State Space of the Premotor and Parietal Grasping Network
Predicting Reaction Time from the Neural State Space of the Premotor and Parietal Grasping Network
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DOI：
10.1523/jneurosci.1714-15.2015
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发表时间：
2015-08-12
影响因子：
5.3
通讯作者：
Scherberger, Hansjoerg
中科院分区：
文献类型：
--
作者：
Michaels, Jonathan A.;Dann, Benjamin;Scherberger, Hansjoerg
参与规划和执行抓握动作的大脑神经网络尚未完全了解。猕猴腹侧前运动皮层的前顶内区（AIP）和手区（F5）形成的网络与抓握运动的产生密切相关。然而，在这个额顶叶网络中，每个区域的不同作用尚不清楚。我们记录了尖峰活动，从许多电极在AIP和F5平行，而三只猕猴（猕猴）进行延迟抓任务。通过分析动作准备过程中的神经群体活动，我们发现同时记录的单元的状态空间分析比传统方法更能预测随后的反应时间（RT）。此外，由于我们观察到各种各样的个体单元特征，我们开发了神经群体平均的符号校正平均率（SCAR）方法。SCAR方法能够解释至少与状态空间方法一样多的RT总体方差。总体而言，F5活性预测RT（解释18%的方差）显著优于AIP（6%）。SCAR方法提供了一个简单的解释人口活动，虽然其他状态空间方法可以提供更丰富的人口动态的描述。总之，这些结果支持顶叶和额叶皮层在准备抓握中的不同作用，这表明F5中准备活动的变异性对试验RT变异性的影响比AIP更强。
Neural networks of the brain involved in the planning and execution of grasping movements are not fully understood. The network formed by macaque anterior intraparietal area (AIP) and hand area (F5) of the ventral premotor cortex is implicated strongly in the generation of grasping movements. However, the differential role of each area in this frontoparietal network is unclear. We recorded spiking activity from many electrodes in parallel in AIP and F5 while three macaque monkeys (Macaca mulatta) performed a delayed grasping task. By analyzing neural population activity during action preparation, we found that state space analysis of simultaneously recorded units is significantly more predictive of subsequent reaction times (RTs) than traditional methods. Furthermore, because we observed a wide variety of individual unit characteristics, we developed the sign-corrected average rate (SCAR) method of neural population averaging. The SCAR method was able to explain at least as much variance in RT overall as state space methods. Overall, F5 activity predicted RT (18% variance explained) significantly better than AIP (6%). The SCAR methods provides a straightforward interpretation of population activity, although other state space methods could provide richer descriptions of population dynamics. Together, these results lend support to the differential role of the parietal and frontal cortices in preparation for grasping, suggesting that variability in preparatory activity in F5 has a more potent effect on trial-to-trial RT variability than AIP.