Schott Björn H, Soch Joram, Kizilirmak Jasmin M, Schütze Hartmut, Assmann Anne, Maass Anne, Ziegler Gabriel, Sauvage Magdalena, Richter Anni
German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.
Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.
iScience. 2023 Aug 29;26(10):107765. doi: 10.1016/j.isci.2023.107765. eCollection 2023 Oct 20.
Successful explicit memory encoding is associated with inferior temporal activations and medial parietal deactivations, which are attenuated in aging. Here we used dynamic causal modeling (DCM) of functional magnetic resonance imaging data to elucidate effective connectivity patterns between hippocampus, parahippocampal place area (PPA), and precuneus during encoding of novel visual scenes. In 117 young adults, DCM revealed pronounced activating input from the PPA to the hippocampus and inhibitory connectivity from the PPA to the precuneus during novelty processing, with both being enhanced during successful encoding. This pattern could be replicated in two cohorts (N = 141 and 148) of young and older adults. In both cohorts, older adults selectively exhibited attenuated inhibitory PPA-precuneus connectivity, which correlated negatively with memory performance. Our results provide insight into the network dynamics underlying explicit memory encoding and suggest that age-related differences in memory-related network activity are, at least partly, attributable to altered temporo-parietal neocortical connectivity.
成功的外显记忆编码与颞下回激活和顶叶内侧失活有关，而这些在衰老过程中会减弱。在这里，我们使用功能磁共振成像数据的动态因果模型（DCM）来阐明在新视觉场景编码期间海马体、海马旁回位置区（PPA）和楔前叶之间的有效连接模式。在117名年轻人中，DCM显示在新奇性处理期间，从PPA到海马体有明显的激活输入，从PPA到楔前叶有抑制性连接，在成功编码期间两者都增强。这种模式可以在两组年轻人和老年人（N = 141和148）中复制。在两组中，老年人选择性地表现出减弱的PPA-楔前叶抑制性连接，这与记忆表现呈负相关。我们的结果为外显记忆编码背后的网络动态提供了见解，并表明与记忆相关的网络活动中的年龄相关差异至少部分归因于颞顶叶新皮质连接的改变。
