In this study we used functional MRI (fMRI) to examine whether defining a stimulus as a target affects brain activation associated with a verbal working memory (WM) task. Seventeen healthy right-handed volunteers performed a Sternberg task with three consonants as memory set. We performed a region of interest based fMRI analysis to examine differences in brain activity patterns between targets and non-targets. Non-target brain activity was subtracted from target activity and hemispheric and fronto-parietal differences were tested by conducting a MANOVA. Participants responded correctly to 97.5% of the stimuli. The fMRI results showed a hemisphere by fronto-parietal location interaction, where targets evoked increased activity in the right frontal regions compared to non-targets, whereas the left frontal task activation did not differ between targets and non-targets. In the parietal regions, targets evoked increased activity compared to non-targets in the lateral anterior, but not the medial posterior part. Our study revealed that defining a stimulus as a target within a verbal WM task evokes an increase in brain activity in right frontal brain regions, compared to non-targets. Our results suggest an important hemispheric differentiation in target processing, in which the right frontal cortex is predominantly involved in processes associated with target stimuli. The left frontal cortex does not differentiate between processing target and non-target stimuli, suggesting involvement in WM processes that are independent of stimulus type. Parietal, the lateral anterior part is predominantly involved in target processing, while the medial posterior part does not differentiate between target and non-target processing.

中文翻译：

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语言工作记忆中目标和非目标的处理。

在这项研究中，我们使用功能性MRI（fMRI）来检查将刺激定义为目标是否会影响与口头工作记忆（WM）任务相关的大脑激活。十七名健康的右撇子志愿者以三个辅音作为记忆集执行了Sternberg任务。我们进行了基于兴趣区域的功能磁共振成像分析，以检查目标和非目标之间的大脑活动模式的差异。从目标活动中减去非目标脑活动，并通过进行MANOVA测试半球和额顶叶差异。参与者对97.5％的刺激反应正确。功能磁共振成像结果显示额叶-顶叶位置相互作用引起的半球，与非靶标相比，靶标在右额叶区域引起的活动增加，目标和非目标之间的左额叶任务激活没有差异。在顶区，与外侧外侧前部而非外侧后部的非目标相比，目标引起的活动增加。我们的研究表明，与非目标相比，在口头WM任务中将刺激定义为目标会引起右额脑区域大脑活动的增加。我们的结果表明，在靶标处理中存在重要的半球分化，其中右额叶皮层主要参与与靶标刺激相关的过程。左额叶皮层在处理目标刺激和非目标刺激之间没有区别，表明参与了与刺激类型无关的WM过程。顶叶，外侧前部主要参与靶标处理，