Cognitive Neuro Science at the Centre for Psychiatry, Justus Liebig University, Giessen, Germany.
PLoS One. 2012;7(5):e36089. doi: 10.1371/journal.pone.0036089. Epub 2012 May 1.
Prolonged response times are observed with targets having been presented as distractors immediately before, called negative priming effect. Among others, inhibitory and retrieval processes have been suggested underlying this behavioral effect. As those processes would involve different neural activation patterns, a functional magnetic resonance imaging (fMRI) study including 28 subjects was conducted. Two tasks were used to investigate stimulus repetition effects. One task focused on target location, the other on target identity. Both tasks are known to elicit the expected response time effects. However, there is less agreement about the relationship of those tasks with the explanatory accounts under consideration. Based on within-subject comparisons we found clear differences between the experimental repetition conditions and the neutral control condition on neural level for both tasks. Hemodynamic fronto-striatal activation patterns occurred for the location-based task favoring the selective inhibition account. Hippocampal activation found for the identity-based task suggests an assignment to the retrieval account; however, this task lacked a behavioral effect.
当目标作为分心物立即出现在之前时，会观察到反应时间延长，这被称为负启动效应。除其他因素外，抑制和检索过程被认为是这种行为效应的基础。由于这些过程将涉及不同的神经激活模式，因此进行了一项包括 28 名受试者的功能磁共振成像 (fMRI) 研究。使用了两个任务来研究刺激重复效应。一个任务侧重于目标位置，另一个任务侧重于目标身份。这两个任务都已知会引起预期的反应时间效应。然而，关于这些任务与正在考虑的解释性说明之间的关系，还没有达成一致意见。基于受试者内比较，我们发现两个任务的实验重复条件与中性对照条件在神经水平上存在明显差异。基于位置的任务的额纹状体激活模式有利于选择性抑制说明。在基于身份的任务中发现的海马体激活表明属于检索说明；然而，这个任务缺乏行为效应。
