Stern Emily R, Wager Tor D, Egner Tobias, Hirsch Joy, Mangels Jennifer A
Department of Psychology, Columbia University, New York, NY 10027, USA.
Brain Res. 2007 Oct 24;1176:92-102. doi: 10.1016/j.brainres.2007.07.060. Epub 2007 Aug 9.
Advance preparation has been shown to improve the efficiency of conflict resolution. Yet, with little empirical work directly linking preparatory neural activity to the performance benefits of advance cueing, it is not clear whether this relationship results from preparatory activation of task-specific networks, or from activity associated with general alerting processes. Here, fMRI data were acquired during a spatial Stroop task in which advance cues either informed subjects of the upcoming relevant feature of conflict stimuli (spatial or semantic) or were neutral. Informative cues decreased reaction time (RT) relative to neutral cues, and cues indicating that spatial information would be task-relevant elicited greater activity than neutral cues in multiple areas, including right anterior prefrontal and bilateral parietal cortex. Additionally, preparatory activation in bilateral parietal cortex and right dorsolateral prefrontal cortex predicted faster RT when subjects responded to spatial location. No regions were found to be specific to semantic cues at conventional thresholds, and lowering the threshold further revealed little overlap between activity associated with spatial and semantic cueing effects, thereby demonstrating a single dissociation between activations related to preparing a spatial versus semantic task-set. This relationship between preparatory activation of spatial processing networks and efficient conflict resolution suggests that advance information can benefit performance by leading to domain-specific biasing of task-relevant information.
研究表明,提前准备能够提高冲突解决的效率。然而,由于直接将准备阶段的神经活动与提前提示的行为益处联系起来的实证研究较少,目前尚不清楚这种关系是源于特定任务网络的准备性激活,还是与一般警觉过程相关的活动。在此,我们在一项空间Stroop任务中采集了功能磁共振成像(fMRI)数据,在该任务中,提前提示要么告知受试者即将出现的冲突刺激的相关特征(空间或语义),要么为中性提示。与中性提示相比,信息性提示缩短了反应时间(RT),并且表明空间信息与任务相关的提示在多个区域(包括右侧前额叶前部和双侧顶叶皮层)引发的活动比中性提示更强。此外,当受试者对空间位置做出反应时,双侧顶叶皮层和右侧背外侧前额叶皮层的准备性激活预示着更快的反应时间。在传统阈值下,未发现有区域对语义提示具有特异性,进一步降低阈值后发现,与空间和语义提示效应相关的活动之间几乎没有重叠,从而证明了与准备空间任务集和语义任务集相关的激活之间存在单一分离。空间处理网络的准备性激活与高效冲突解决之间的这种关系表明,提前信息可以通过导致任务相关信息的特定领域偏向来提高表现。