Areas in frontoparietal cortex have been shown to be active in a range of cognitive tasks and have been proposed to play a key role in goal-driven activities (Dosenbach, N. U. F., Fair, D. A., Miezin, F. M., Cohen, A. L., Wenger, K. K., Dosenbach, R. A. T., et al. Distinct brain networks for adaptive and stable task control in humans. Proceedings of the National Academy of Sciences, U.S.A., 104, 11073–11078, 2007; Duncan, J. The multiple-demand (MD) system of the primate brain: Mental programs for intelligent behavior. Trends in Cognitive Sciences, 14, 172–179, 2010). Here, we examine the role this frontoparietal system plays in visual search. Visual search, like many complex tasks, consists of a sequence of operations: target selection, stimulus–response (SR) mapping, and response execution. We independently manipulated the difficulty of target selection and SR mapping in a novel visual search task that involved identical stimulus displays. Enhanced activity was observed in areas of frontal and parietal cortex during both difficult target selection and SR mapping. In addition, anterior insula and ACC showed preferential representation of SR-stage information, whereas the medial frontal gyrus, precuneus, and inferior parietal sulcus showed preferential representation of target selection-stage information. A connectivity analysis revealed dissociable neural circuits underlying visual search. We hypothesize that these circuits regulate distinct mental operations associated with the allocation of spatial attention, stimulus decisions, shifts of task set from selection to SR mapping, and SR mapping. Taken together, the results show frontoparietal involvement in all stages of visual search and a specialization with respect to cognitive operations.

额顶皮层区域已被证明在一系列认知任务中活跃，并被提议在目标驱动的活动中发挥关键作用（Dosenbach、NUF、Fair、DA、Miezin、FM、Cohen、AL、Wenger、KK , Dosenbach, RAT, et al. 用于人类适应性和稳定任务控制的不同大脑网络.美国国家科学院院刊, 104 , 11073–11078, 2007; Duncan, J. 多需求 (MD) 系统灵长类动物的大脑：智能行为的心理程序。认知科学趋势，14, 172–179, 2010)。在这里，我们研究了这个额顶系统在视觉搜索中的作用。与许多复杂任务一样，视觉搜索由一系列操作组成：目标选择、刺激-响应 (SR) 映射和响应执行。我们在涉及相同刺激显示的新视觉搜索任务中独立操纵了目标选择和 SR 映射的难度。在困难的目标选择和 SR 映射期间，在额叶和顶叶皮层区域观察到增强的活动。此外，前脑岛和 ACC 显示出 SR 阶段信息的优先表示，而内侧额回、楔前叶和顶下沟显示出目标选择阶段信息的优先表示。连接分析揭示了视觉搜索背后的可分离神经回路。我们假设这些回路调节与空间注意力分配、刺激决策、任务集从选择到 SR 映射和 SR 映射的转移相关的不同心理操作。综上所述，结果显示额顶参与视觉搜索的所有阶段以及认知操作的专业化。