Shedding light on gray(ing) areas: Connectivity and task switching dynamics in aging
Shedding light on gray(ing) areas: Connectivity and task switching dynamics in aging
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DOI：
10.1111/psyp.12818
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发表时间：
2018-03-01
期刊：
影响因子：
3.7
通讯作者：
Fabiani，Monica
中科院分区：
文献类型：
--
作者：
Baniqued，Pauline L.;Low，Kathy A.;Fabiani，Monica
要求控制的任务依赖于额顶网络区域之间的沟通，这些区域经历了显著的年龄相关衰退。在这里，我们整合了来自大脑解剖学，电生理学（ERP）和光学成像（事件相关光学信号，EROS）的数据，以表征中老年人准备控制过程的空间和时间动态。老年人参与了一项需要在位置和意义任务（空间Stroop）之间切换的实验，这一范式已被证明主要招募相对半球的前额叶皮层，并被认为涉及胼胝体（CC）。在中年受试者中，转换试验在准备期早期产生了比F3更大的消极性。在整个老年人样本中，这种转换相关的额叶负性与反应时间（RT）转换成本和左额中回（MFG）中EROS转换相关的上调相关。前CC体积与转换成本不直接相关，尽管CC体积预测左MFG和右MFG的任务依赖性耦合。重要的是，左MFG种子滞后交叉相关揭示了任务依赖性连接;在右半球依赖性位置任务中，左MFG和右MFG之间的转换相关耦合的时间和强度显著预测了RT转换成本，即使在控制了年龄，CC量和F3转换效应之后。总之，这些结果表明，一个强大的功能连接，可能取决于底层结构连接的完整性，是至关重要的，能够满足需求的转移处理跨半球，以及难以从事这种控制动态导致次优性能。
Control‐demanding tasks rely on communication among regions of the frontoparietal network, areas that undergo significant age‐related decline. Here, we integrate data from brain anatomy, electrophysiology (ERPs), and optical imaging (event‐related optical signals, EROS) to characterize the spatial and temporal dynamics of preparatory control processes in middle to old age. Older adults participated in an experiment that required switching between a position and a meaning task (spatial Stroop), a paradigm that has been shown to primarily recruit prefrontal cortex in opposite hemispheres and is thought to involve the corpus callosum (CC). In middle‐aged participants, switch trials resulted in greater negativity over F3 early in the preparatory period. Across the whole older adult sample, this switch‐related frontal negativity was correlated with reaction time (RT) switch costs and EROS switch‐related upregulation in the left middle frontal gyrus (MFG). Anterior CC volume was not directly correlated with switch costs, although CC volume predicted task‐dependent coupling of left MFG and right MFG. Crucially, left MFG‐seeded lagged cross‐correlations revealed task‐dependent connectivity; in the right‐hemisphere‐dependent position task, the timing and strength of switch‐related coupling between left MFG and right MFG significantly predicted RT switch costs, even after controlling for age, CC volume, and the F3 switch effect. Together, these results suggest that a strong functional connectivity, likely hinged on the integrity of the underlying structural connections, is critical to being able to meet the demands of shifting processing across hemispheres, and that difficulty engaging such control dynamics leads to suboptimal performance.