Dept. of Experimental Psychology, Ghent University, 9000 Ghent, Belgium.
Neuroimage. 2013 Jul 1;74:179-87. doi: 10.1016/j.neuroimage.2013.02.027. Epub 2013 Feb 21.
Goal-directed behavior requires the ability to focus on information that is relevant to a given task and to ignore information that might interfere with it. In the Stroop task, for example, the influence of an irrelevant word needs to be overcome, which is believed to be difficult because it arises in a fast and automatic fashion, which effectively renders it very salient. Here we address the question of whether this can be counteracted by increasing the saliency of the task-relevant input, for example by modulating its relative novelty, which increases saliency in a fairly implicit and controlled fashion. To test the influence of novelty on interference processing, we employed a picture-word interference task in the fMRI scanner, in which we manipulated the novelty of the task-relevant picture. We found that picture novelty indeed reduced typical behavioral interference from incongruent words. Moreover, familiar incongruent trials were associated with activity increases in the anterior cingulate cortex (ACC), a prime conflict-processing region, as well as in the noradrenergic locus coeruleus (LC), which entertains connections both to and from the ACC. The lack of analogous activations in novel incongruent trials suggests that the reduction of behavioral interference was not related to enhanced conflict-resolution processes, but rather to the automatic prioritization of novel pictures which appears to avert the influence of irrelevant words at the front end. Interestingly, activity in the ACC and LC was slightly stronger in novel congruent trials compared to incongruent ones, which may reflect increased relevance of novel stimuli when encoded in a congruent context. In summary, the present data demonstrate that stimulus novelty clearly reduces semantic interference, and highlights a complex interaction of interference and novelty processing on the neural level, including an involvement of the noradrenergic system in the processing of cognitively and perceptually salient events.
目标导向行为需要能够专注于与给定任务相关的信息，并忽略可能干扰它的信息。例如，在斯特鲁普任务中，需要克服无关单词的影响，这被认为是困难的，因为它以快速和自动的方式出现，这实际上使其非常突出。在这里，我们探讨了通过增加任务相关输入的显著性是否可以抵消这种影响，例如通过调节其相对新颖性，这以相当隐含和可控的方式增加了显著性。为了测试新颖性对干扰处理的影响，我们在 fMRI 扫描仪中使用了图片-单词干扰任务，在该任务中，我们操纵了任务相关图片的新颖性。我们发现，图片新颖性确实减少了来自不一致单词的典型行为干扰。此外，熟悉的不一致试验与前扣带皮层（ACC）的活动增加有关，ACC 是一个主要的冲突处理区域，以及去甲肾上腺素能蓝斑核（LC），它与 ACC 既有关联又有联系。在新颖的不一致试验中没有类似的激活表明，行为干扰的减少与增强的冲突解决过程无关，而是与新颖图片的自动优先级有关，这似乎在前端避免了无关单词的影响。有趣的是，与不一致的试验相比，在新颖的一致试验中，ACC 和 LC 的活动稍强，这可能反映了当在一致的背景下编码时，新颖刺激的相关性增加。总之，本研究数据表明，刺激新颖性明显降低了语义干扰，并突出了干扰和新颖性处理在神经水平上的复杂相互作用，包括去甲肾上腺素系统在认知和感知上突出事件的处理中的参与。
