Differential contribution of superior parietal and dorsal-lateral prefrontal cortices in copying
Differential contribution of superior parietal and dorsal-lateral prefrontal cortices in copying
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DOI：
10.1016/j.cortex.2008.02.007
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发表时间：
2009-03-01
期刊：
影响因子：
3.6
通讯作者：
Georgopoulos, Apostolos P.
中科院分区：
文献类型：
--
作者：
Averbeck, Bruno B.;Crowe, David A.;Georgopoulos, Apostolos P.
在这项研究中，我们研究了不同的贡献上级顶叶皮层（SPC）和尾部背外侧前额叶皮层（dlPFC）绘制几何形状。猴子被训练画三角形、正方形、长方形和倒三角形，而我们记录了尾侧46区和顶叶皮质5区和2区的小神经元群的活动。我们通过拟合逐步的一般线性模型来分析由单个神经元编码的绘图因子，该模型使用所产生的轨迹的片段上的平均发射率作为我们的因变量。该分析表明，认知（形状和节段序列位置）和运动（最大速度，位置和方向的节段）因素调制单个神经元的活动。此外，SPC有丰富的形状和运动因素的代表性，与运动的富集比形状enrichment.Following，我们使用的同时记录的神经合奏的活动来预测手的速度。在这些分析中，我们发现，当我们为每个形状估计不同的线性解码函数时，手速的预测比我们在形状上估计单个函数时更好，尽管这是一个微妙的影响。此外，我们还发现，合奏的尾部dlPFC神经元进行了大量的信息，手的速度，一个纯粹的运动因素。然而，SPC合奏进行更多的信息，在合奏水平作为合奏大小的函数比尾侧dlPFC合奏，虽然差异并不显着。最后，对单个神经元的反应潜伏期的分析表明，尾侧dlPFC代表性比SPC代表性更感觉，SPC代表性同样是感觉和运动。因此，这一神经生理学证据表明，SPC和尾侧dlPFC在绘画中发挥了作用，但SPC在认知和运动组件中发挥了更大的作用。(c)2008 Elsevier Srl. All rights reserved.
In this study we examined the differential contribution of superior parietal cortex (SPC) and caudal dorsal-lateral prefrontal cortex (dlPFC) to drawing geometrical shapes. Monkeys were trained to draw triangles, squares, trapezoids and inverted triangles while we recorded the activity of small ensembles of neurons in caudal area 46 and areas 5 and 2 of parietal cortex. We analyzed the drawing factors encoded by individual neurons by fitting a step-wise general-linear model using as our dependent variable the firing rate averaged over segments of the produced trajectories. This analysis demonstrated that both cognitive (shape and segment serial position) and motor (maximum speed, position and direction of segment) factors modulated the activity of individual neurons. Furthermore, SPC had an enriched representation of both shape and motor factors, with the motor enrichment being stronger than the shape enrichment.Following this we used the activity in the simultaneously recorded neural ensembles to predict the hand velocity. In these analyses we found that the prediction of the hand velocity was better when we estimated different linear decoding functions for each shape than when we estimated a single function across shapes, although it was a subtle effect. Furthermore, we also found that ensembles of caudal dlPFC neurons carried considerable information about hand velocity, a purely motor factor. However, the SPC ensembles carried more information at the ensemble level as a function of the ensemble size than the caudal dlPFC ensembles, although the differences were not dramatic. Finally, an analysis of the response latencies of individual neurons showed that the caudal dlPFC representation was more sensory than the SPC representation, which was equally sensory and motor. Thus, this neurophysiological evidence suggests that both SPC and caudal dlPFC have a role in drawing, but that SPC plays a larger role in both the cognitive and the motor components. (c) 2008 Elsevier Srl. All rights reserved.