What is odd in the oddball task? Prefrontal cortex is activated by dynamic changes in response strategy
What is odd in the oddball task? Prefrontal cortex is activated by dynamic changes in response strategy
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DOI：
10.1016/j.neuropsychologia.2003.07.009
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发表时间：
2004-01-01
期刊：
影响因子：
2.6
通讯作者：
McCarthy, G
中科院分区：
文献类型：
--
作者：
Huettel, SA;McCarthy, G
在“oddball”目标检测任务中，受试者对一系列标准刺激中不频繁和不规则出现的目标刺激做出反应。虽然这些目标的检测可靠地唤起短暂的活动在前额叶皮层区域，它还没有建立这种活动是否是由于选择一个罕见的响应或响应策略的变化。我们研究了这个问题，使用一种新的变体的古怪的任务，结合西蒙效应，同时测量血流动力学大脑活动的前额叶皮层功能磁共振成像（fMRI）。受试者分别观看一系列需要按下左右按钮的圆形和正方形。在90%的试验（“标准”试验）中，刺激呈现在与反应手相同的视觉半野中，但在10%的试验（“策略改变”试验）中，它们呈现在相反的视觉半野中。在前中额回（MFG），后额下回（IFG）和相邻的岛叶皮层，以及前扣带回（ACG）中发现了显着的激活，以罕见的策略改变试验。这些区域对应于先前报告的oddball相关激活，在受试者中一致。行为结果支持我们的解释，即受试者加强了基于位置的反应策略，这是抑制的策略改变试验。活动内的MFG和ACG是更大的错误试验比正确的试验，而IFG活动之间的错误和正确的试验是相似的。我们的结论是，背外侧前额叶皮层（dlPFC）与动态变化的映射刺激的反应（如反应策略），独立于任何行为的变化。(C)2003 Elsevier Ltd.保留所有权利。
In the "oddball" target detection task, subjects respond to target stimuli that occur infrequently and irregularly within a series of standard stimuli. Although detection of these targets reliably evokes transient activity in prefrontal cortical regions, it has not been established whether this activity is due to selection of an infrequent response or to changes in response strategy. We investigated this issue using a novel variant of the oddball task that incorporated the Simon effect, while measuring hemodynamic brain activity in prefrontal cortex using functional magnetic resonance imaging (fMRI). Subjects viewed a series of circles and squares that required left and right button presses, respectively. On 90% of trials ("standard" trials), the stimuli were presented in the same visual hemifield as the hand of response, but on 10% of trials ("strategy-change" trials) they were presented in the opposite visual hemifield. Significant activation to the infrequent strategy-change trials was found in the anterior middle frontal gyrus (MFG), the posterior inferior frontal gyrus (IFG) and adjacent insular cortex, and in the anterior cingulate gyrus (ACG). These regions, which correspond to previous reports of oddball-related activation, were consistent across subjects. Behavioral results supported our interpretation that subjects potentiated a position-based response strategy, which was inhibited on the strategy-change trials. Activity within the MFG and ACG was much greater on error trials than on correct trials, while IFG activity was similar between error and correct trials. We conclude that the dorsolateral prefrontal cortex (dlPFC) is associated with dynamic changes in the mapping of stimuli to responses (e.g. response strategies), independently of any changes in behavior. (C) 2003 Elsevier Ltd. All rights reserved.