Object working memory performance depends on microstructure of the frontal-occipital fasciculus.
Object working memory performance depends on microstructure of the frontal-occipital fasciculus.
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DOI：
10.1089/brain.2011.0037
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发表时间：
2011
影响因子：
3.4
通讯作者：
Courtney SM
中科院分区：
文献类型：
--
作者：
Walsh M;Montojo CA;Sheu YS;Marchette SA;Harrison DM;Newsome SD;Zhou F;Shelton AL;Courtney SM
涉及额叶皮层和其他大脑区域之间的交流的再入回路被假设为维持工作记忆中代表信息的神经活动的持续模式所必需，但迄今为止证据都是间接的。如果工作记忆的维持确实依赖于这种时间上精确而强大的远距离交流，那么延迟识别任务的表现应该高度依赖于连接感觉区域和前额皮质的白质束的微观结构完整性。本研究在两组不同的受试者中探讨了白质微观结构的变化对工作记忆表现的影响：多发性硬化症（MS）患者和年龄和性别匹配的健康成年人。我们使用功能性磁共振成像来揭示与空间和物体工作记忆有关的皮层区域，这些区域通过扩散张量束图来定义感兴趣的特定额外白质束。在剔除年龄和皮质脊髓束的微观结构差异后，我们发现客体工作记忆任务中产生的错误数量与额枕下束的微观结构有特殊的关系。这一结果独立适用于两组受试者，提供了两种不同类型白质结构变异的研究内复制：ms相关损伤和正常变异。研究结果表明，前额叶皮层的特定区域和感觉皮层之间的相互作用对于优先激活这些区域的非空间工作记忆任务的重要性。
Re-entrant circuits involving communication between frontal cortex and other brain areas have been hypothesized to be necessary for maintaining the sustained patterns of neural activity that represent information in working memory, but evidence has so far been indirect. If working memory maintenance indeed depends on such temporally precise and robust long-distance communication, then performance on a delayed recognition task should be highly dependent on the microstructural integrity of white matter tracts connecting sensory areas with prefrontal cortex. Here the effect of variations in white matter microstructure on working memory performance was explored in two separate groups of subjects: individuals with multiple sclerosis (MS) and age- and gender-matched healthy adults. We used functional magnetic resonance imaging to reveal cortical regions involved in spatial and object working memory, which were used to define specific frontal to extrastriate white matter tracts of interest via diffusion tensor tractography. After factoring out variance due to age and the microstructure of a control tract, the corticospinal tract, it was found that the number of errors produced in the object working memory task was specifically related to the microstructure of the inferior frontal-occipital fasciculus. This result held for both subject groups, independently, providing a within-study replication with two different types of white matter structural variability: MS-related damage and normal variation. The results demonstrate the importance of interactions between specific regions of the prefrontal cortex and sensory cortices for a nonspatial working memory task that preferentially activates those regions.