Sensitivity of prefrontal cortex to changes in target probability: A functional MRI study
Sensitivity of prefrontal cortex to changes in target probability: A functional MRI study
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DOI：
10.1002/hbm.1022
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发表时间：
2001-05-01
影响因子：
4.8
通讯作者：
Noll, DC
中科院分区：
文献类型：
--
作者：
Casey, BJ;Forman, SD;Noll, DC
电生理学研究表明，前额叶皮层对事件发生概率的变化很敏感。本研究的目的是确定前额叶皮层的子区域是否对功能性磁共振成像（fMRI）的目标概率变化有不同的反应。十个右撇子的成年人进行了扫描，使用梯度回波，回波平面成像序列在执行的oddball范例。要求受试者回答除“X”以外的任何字母。目标的频率（即，除X外的任何字母）在不同试验中有所不同。结果表明，背侧前额叶区在非频繁事件中活跃，腹侧前额叶区在频繁事件中活跃。此外，我们观察到背侧和腹侧前额叶区域之间的反比关系，当背侧前额叶区域的活动增加时，腹侧前额叶区域的活动减少，反之亦然。这一发现可能是竞争性认知过程或能力限制的指标。最重要的是，这些发现作为一个整体表明，任何简单的前额叶皮层功能理论都必须考虑到这一区域对目标概率变化的敏感性。Hum.脑图谱13：26-33，2001年。(C)2001 Wiley-Liss，Inc.
Electrophysiological studies suggest sensitivity of the prefrontal cortex to changes in the probability of an event. The purpose of this study was to determine if subregions of the prefrontal cortex respond differentially to changes in target probabilities using functional magnetic resonance imaging (fMRI). Ten right-handed adults were scanned using a gradient-echo, echo planar imaging sequence during performance of an oddball paradigm. Subjects were instructed to respond to any letter but "X". The frequency of targets (i.e., any letter but X) varied across trials. The results showed that dorsal prefrontal regions were active during infrequent events and ventral prefrontal regions were active during frequent events. Further, we observed an inverse relation between the dorsal and ventral prefrontal regions such that when activity in dorsal prefrontal regions increased, activity in ventral prefrontal regions decreased, and vice versa. This finding may index competing cognitive processes or capacity limitations. Most importantly, these findings taken as a whole suggest that any simple theory of prefrontal cortex function must take into account the sensitivity of this region to changes in target probability. Hum. Brain Mapping 13:26-33, 2001. (C) 2001 Wiley-Liss, Inc.