King Danielle R, de Chastelaine Marianne, Elward Rachael L, Wang Tracy H, Rugg Michael D
Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75235
Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75235.
J Neurosci. 2015 Jan 28;35(4):1763-72. doi: 10.1523/JNEUROSCI.3219-14.2015.
Recollection involves retrieving specific contextual details about a prior event. Functional neuroimaging studies have identified several brain regions that are consistently more active during successful versus failed recollection-the "core recollection network." In the present study, we investigated whether these regions demonstrate recollection-related increases not only in activity but also in functional connectivity in healthy human adults. We used fMRI to compare time-series correlations during successful versus unsuccessful recollection in three separate experiments, each using a different operational definition of recollection. Across experiments, a broadly distributed set of regions consistently exhibited recollection-related increases in connectivity with different members of the core recollection network. Regions that demonstrated this effect included both recollection-sensitive regions and areas where activity did not vary as a function of recollection success. In addition, in all three experiments the magnitude of connectivity increases correlated across individuals with recollection accuracy in areas diffusely distributed throughout the brain. These findings suggest that enhanced functional interactions between distributed brain regions are a signature of successful recollection. In addition, these findings demonstrate that examining dynamic modulations in functional connectivity during episodic retrieval will likely provide valuable insight into neural mechanisms underlying individual differences in memory performance.
回忆涉及检索有关先前事件的特定情境细节。功能性神经影像学研究已经确定了几个脑区，在成功回忆与失败回忆过程中，这些脑区始终表现出更强的激活——即“核心回忆网络”。在本研究中，我们调查了这些脑区在健康成年人中是否不仅在活动方面，而且在功能连接性方面都表现出与回忆相关的增加。我们使用功能磁共振成像（fMRI）在三个独立实验中比较了成功回忆与不成功回忆期间的时间序列相关性，每个实验都使用了不同的回忆操作定义。在所有实验中，一组广泛分布的脑区始终表现出与核心回忆网络的不同成员之间与回忆相关的连接性增加。表现出这种效应的脑区既包括对回忆敏感的区域，也包括活动不随回忆成功与否而变化的区域。此外，在所有三个实验中，连接性增加的幅度在个体间与大脑中广泛分布区域的回忆准确性相关。这些发现表明，分布式脑区之间增强的功能相互作用是成功回忆的一个特征。此外，这些发现表明，在情景检索过程中检查功能连接性的动态调制可能会为记忆表现个体差异背后的神经机制提供有价值的见解。
