Hippocampus-dependent and -independent theta-networks of active maintenance
Hippocampus-dependent and -independent theta-networks of active maintenance
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DOI：
10.1073/pnas.0904823106
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发表时间：
2009-12-01
影响因子：
11.1
通讯作者：
Duzel, Emrah
中科院分区：
文献类型：
--
作者：
Cashdollar, Nathan;Malecki, Ulrike;Duzel, Emrah
最近对人类和动物的研究提出了一种可能性，即在工作记忆中积极地保持对场景的详细记忆可能需要海马体，海马体是一种以其在长期记忆中的作用而闻名的大脑结构。通过协调枕叶和颞叶大脑区域在θ频率范围内的同步，我们发现海马体在行为和功能上对构型关系（CR）维持至关重要。通过对健康成人和双侧海马硬化症患者的脑磁图分析，我们将海马依赖的θ网络与独立于海马并用于非cr场景维持的θ网络区分开来。这种非cr θ网络涉及大脑额叶和顶叶区域。我们还表明，这两个网络之间的功能和地形分离不能用感知困难或要维持的信息量（“负载”）来解释。此外，我们在健康成人中证实，在延迟期间，任务干扰会以类似于工作记忆维持过程的方式损害对场景中物体的CR安排的主动维持。总之，这些发现需要重新考虑长期记忆和短期记忆之间的经典功能解剖学区别。
Recent studies in humans and animals raise the possibility that actively maintaining a detailed memory of a scene within working memory may require the hippocampus, a brain structure better known for its role in long-term memory. We show that the hippocampus is behaviorally and functionally critical for configural-relational (CR) maintenance by orchestrating the synchrony of occipital and temporal brain regions in the theta-frequency range. Using magnetoencephalography in healthy adults and patients with bilateral hippocampal sclerosis, we distinguish this hippocampus-dependent theta-network from one that is independent of the hippocampus and used for non-CR scene maintenance. This non-CR theta-network involved frontal and parietal brain regions. We also show that the functional and topographical dissociation between these two networks cannot be accounted for by perceptual difficulty or the amount of information to be maintained ("load"). Also, we confirm in healthy adults that active maintenance of the CR arrangement of objects within a scene is impaired by task-interference during the delay in a manner akin to working-memory maintenance processes. Together, these findings demand reconsideration of the classical functional-anatomical distinctions between long-and short-term memory.