Increased neural efficiency with repeated performance of a working memory task is information-type dependent
Increased neural efficiency with repeated performance of a working memory task is information-type dependent
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DOI：
10.1093/cercor/bhj007
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发表时间：
2006-05-01
期刊：
影响因子：
3.7
通讯作者：
Courtney, SM
中科院分区：
文献类型：
--
作者：
Sayala, S;Sala, JB;Courtney, SM
工作记忆任务不同于那些通过练习产生自动的刺激-反应关联的任务，它被认为在重复执行后仍然需要认知控制过程。以往关于工作记忆任务重复的研究与这一点雅阁一致。然而，目前还不清楚是否在重复后的神经活动的变化意味着改变一般控制过程中常见的所有WM任务或特定的选择，编码和维护相关信息。在本研究中，功能磁共振成像（fMRI）被用来检查在重复的对象和空间延迟识别任务的样本，延迟和测试期间的变化。我们发现，在空间WM任务重复后，空间和对象选择区域的fMRI激活减少，独立于行为表现。客体工作记忆任务重复后，很少有脑区的活动发生变化。这些结果表明，空间任务的重复导致提高效率的维护任务相关的信息和提高能力，以过滤出任务无关的信息。这种重复效应对空间任务的特异性表明，物体和空间信息的表征性质存在差异，它们在WM中的维持可能受不同神经系统的影响。
Unlike tasks in which practice leads to an automatic stimulus-response association, it is thought working memory (WM) tasks continue to require cognitive control processes after repeated performance. Previous studies investigating WM task repetition are in accord with this. However, it is unclear whether changes in neural activity after repetition imply alterations in general control processes common to all WM tasks or are specific to the selection, encoding and maintenance of the relevant information. In the present study, functional magnetic resonance imaging (fMRI) was used to examine changes during sample, delay and test periods during repetition of both object and spatial delayed recognition tasks. We found decreases in fMRI activation in both spatial and object-selective areas after spatial WM task repetition, independent of behavioral performance. Few areas showed changed activity after object WM task repetition. These results indicate that spatial task repetition leads to increased efficiency of maintaining task-relevant information and improved ability to filter out task-irrelevant information. The specificity of this repetition effect to the spatial task suggests a difference exists in the nature of the representation of object and spatial information and that their maintenance in WM is likely subserved by different neural systems.