Cansino Selene, Trejo-Morales Patricia, Estrada-Manilla Cinthya, Pasaye-Alcaraz Erick Humberto, Aguilar-Castañeda Erika, Salgado-Lujambio Perla, Sosa-Ortiz Ana Luisa
Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico.
Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico.
Neuropsychologia. 2017 Aug;103:168-182. doi: 10.1016/j.neuropsychologia.2017.07.016. Epub 2017 Jul 19.
Aging effects on regional brain activation have been studied extensively to explain the gradual recollection failure that occurs with advancing age. However, little is known about the consequence of aging on the interaction among brain regions that support recollection. The purpose of this study was to examine effective connectivity at encoding and retrieval during successful and unsuccessful recollection in young and old adults. In particular, we analyzed a recollection network that is characterized by its susceptibility to aging effects by middle age or later, which is comprised of the occipital cortex, hippocampus and orbitofrontal cortex. Participants' brains were scanned using functional magnetic resonance imaging while they performed a spatial source memory task. Dynamic causal modeling and Bayesian model selection revealed that subsequent recollection during encoding and recollection during retrieval modulated the influence of the orbitofrontal cortex on the hippocampus in both age groups; this particular connectivity was not modulated by unsuccessful encoding in either group. Successful encoding and retrieval of item-source associations modulated all connections within the network in old adults. The findings revealed that the orbitofrontal cortex influences processes in the hippocampus to ensure successful recollection, and aging alters the recollection network by engaging non-specialized connections.
衰老对大脑区域激活的影响已得到广泛研究，以解释随着年龄增长逐渐出现的记忆衰退。然而，关于衰老对支持记忆的大脑区域之间相互作用的影响却知之甚少。本研究的目的是检查年轻人和老年人在成功和不成功记忆过程中编码和检索时的有效连接性。具体而言，我们分析了一个记忆网络，该网络的特点是到中年或更晚时易受衰老影响，它由枕叶皮质、海马体和眶额皮质组成。参与者在执行空间源记忆任务时，使用功能磁共振成像对其大脑进行扫描。动态因果模型和贝叶斯模型选择显示，在两个年龄组中，编码期间的后续记忆和检索期间的记忆都调节了眶额皮质对海马体的影响；在任何一组中，这种特定的连接性都不会因编码失败而受到调节。成功编码和检索项目 - 源关联调节了老年人网络内的所有连接。研究结果表明，眶额皮质影响海马体中的过程以确保成功记忆，而衰老通过参与非专门化连接改变了记忆网络。
