Dissociable neural mechanisms underlying response-based and familiarity-based conflict in working memory
Dissociable neural mechanisms underlying response-based and familiarity-based conflict in working memory
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DOI：
10.1073/pnas.1334125100
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发表时间：
2003-09-16
影响因子：
11.1
通讯作者：
Smith, EE
中科院分区：
文献类型：
--
作者：
Nelson, JK;Reuter-Lorenz, PA;Smith, EE
认知控制需要解决相互竞争和潜在冲突的表征之间的干扰。这种冲突可能会出现在刺激输入和响应生成之间的不同点，其净效应是损害绩效。本文的目的是分离不同冲突来源背后的神经机制，以阐明实现认知控制的神经系统的架构。通过使用功能性磁共振成像和言语工作记忆任务（项目识别），我们检查了与两种具有可比行为后果的冲突相关的大脑活动。在我们的项目识别任务的试验中，参与者看到了四个字母，然后是保留间隔，以及与工作记忆中保存的字母之一匹配或不匹配的探测字母（分别为正探测和负探测）。在一些试验中，冲突的产生仅仅是因为当前的阴性探针具有很高的熟悉度，并且由于它属于前一试验的目标集。在其他试验中，由于当前的阴性探针也是前一个试验的阳性探针，产生了响应级别的冲突，因此出现了额外的冲突。与之前的研究一致，由于高度熟悉而产生的冲突与左前额叶激活有关，但与前扣带回激活无关。与高熟悉度冲突试验相比，反应冲突条件与前扣带皮层激活相关，但没有额外的左前额叶激活。这种双重解离表明特定皮层区域对认知控制的不同贡献，这是基于冲突的根源。
Cognitive control requires the resolution of interference among competing and potentially conflicting representations. Such conflict can emerge at different points between stimulus input and response generation, with the net effect being that of compromising performance. The goal of this article was to dissociate the neural mechanisms underlying different sources of conflict to elucidate the architecture of the neural systems that implement cognitive control. By using functional magnetic resonance imaging and a verbal working memory task (item recognition), we examined brain activity related to two kinds of conflict with comparable behavioral consequences. In a trial of our item-recognition task, participants saw four letters, followed by a retention interval, and a probe letter that did or did not match one of the letters held in working memory (positive probe and negative probe, respectively). On some trials, conflict arose solely because of the current negative probe having a high familiarity, due to its membership in the immediately preceding trial's target set. On other trials, additional conflict arose because of the current negative probe having also been a positive probe on the immediately preceding trial, producing response-level conflict. Consistent with previous work, conflict due to high familiarity was associated with left prefrontal activation, but not with anterior cingulate activation. The response-conflict condition, when compared with high-familiarity conflict trials, was associated with anterior cingulate cortex activation, but with no additional left prefrontal activation. This double dissociation points to differing contributions of specific cortical areas to cognitive control, which are based on the source of conflict.