Critical time course of right frontoparietal involvement in mental number space.
Critical time course of right frontoparietal involvement in mental number space.
复制标题
右额顶叶参与心理数字空间的关键时间过程。
DOI：
10.1162/jocn_a_00330
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发表时间：
2013
影响因子：
3.2
通讯作者：
Rusconi E
中科院分区：
文献类型：
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作者：
Rusconi E
神经心理学、神经生理学和神经影像学研究表明，右额顶回路可能是处理心理数字空间（也称为心理数字线（MNL））所必需的。在这里，我们试图指定的关键时间过程中的三个节点，以前已经与MNL处理：右后顶叶皮层（rPPC），右FEF（rFEF），右额下回（rIFG）。在21名参与者中研究了以120%距离调整的个体运动阈值提供的单脉冲TMS的效果，从中央数字（1-9，排除5）开始的0-400 msec（采样间隔= 33 msec）的窗口内。脉冲以随机顺序递送，并且在每个时间点具有相等的概率，与noTMS试验混合。为了分析TMS是否以及何时干扰MNL处理，我们将双峰高斯函数拟合到观察到的数据，并测量对响应代码的空间-数值关联（SNARC）效应（即，对于小数字的左键响应优于右键响应，对于大数字的右键响应优于左键响应），以及在总体性能效率方面具有优势。我们发现，在单手按键反应的幅度判断过程中，TMS在rFEF（小数字和大数字）和rIFG（小数字）传递时，在拟合函数的早期（约25-60 msec）降低了SNARC效应; TMS在rFEF传递时（约200 msec）的后期进一步降低了小数字的SNARC效应。与此相反，TMS的rPPC没有干扰SNARC效应，但一般会降低性能为小的数字和增强它为大的数字，从而产生一种模式，让人想起“忽视”在心理数字空间。我们的研究结果证实了一个完整的右额顶叶网络在心理数字空间处理的因果关系的作用。他们还表明，rPPC是专门绑定到明确的数字幅度处理和rFEF和rIFG有助于接口的心理视觉空间代码与偏侧反应代码。总的来说，我们的研究结果表明，腹侧和背侧额顶回路的因果关系和功能连接的映射数字的空间。
Neuropsychological, neurophysiological, and neuroimaging studies suggest that right frontoparietal circuits may be necessary for the processing of mental number space, also known as the mental number line (MNL). Here we sought to specify the critical time course of three nodes that have previously been related to MNL processing: right posterior parietal cortex (rPPC), right FEF (rFEF), and right inferior frontal gyrus (rIFG). The effects of single-pulse TMS delivered at 120% distance-adjusted individual motor threshold were investigated in 21 participants, within a window of 0–400 msec (sampling interval = 33 msec) from the onset of a central digit (1–9, 5 excluded). Pulses were delivered in a random order and with equal probability at each time point, intermixed with noTMS trials. To analyze whether and when TMS interfered with MNL processing, we fitted bimodal Gaussian functions to the observed data and measured effects on changes in the Spatial–Numerical Association of Response Codes (SNARC) effect (i.e., an advantage for left- over right-key responses to small numbers and right- over left-key responses to large numbers) and in overall performance efficiency. We found that, during magnitude judgment with unimanual key-press responses, TMS reduced the SNARC effect in the earlier period of the fitted functions (∼25–60 msec) when delivered over rFEF (small and large numbers) and rIFG (small numbers); TMS further reduced the SNARC effect for small numbers in a later period when delivered to rFEF (∼200 msec). In contrast, TMS of rPPC did not interfere with the SNARC effect but generally reduced performance for small numbers and enhanced it for large numbers, thus producing a pattern reminiscent of “neglect” in mental number space. Our results confirm the causal role of an intact right frontoparietal network in the processing of mental number space. They also indicate that rPPC is specifically tied to explicit number magnitude processing and that rFEF and rIFG contribute to interfacing mental visuospatial codes with lateralized response codes. Overall, our findings suggest that both ventral and dorsal frontoparietal circuits are causally involved and functionally connected in the mapping of numbers to space.