Department of Psychology, University of Toronto, Toronto, ON, USA.
Rotman Research Institute, Toronto, ON, USA.
Cereb Cortex. 2019 Dec 17;29(11):4568-4579. doi: 10.1093/cercor/bhy334.
Evidence suggests that age differences in associative memory are attenuated for associations that are consistent with prior knowledge. Such knowledge structures have traditionally been associated with the default network (DN), which also shows reduced modulation with age. In the present study, we investigated whether DN activity and connectivity patterns could account for this age-related effect. Younger and older adults underwent functional magnetic resonance imaging as they learned realistic and unrealistic prices of common grocery items. Both groups showed greater activity in the DN during the encoding of realistic, relative to unrealistic, prices. Moreover, DN activity at encoding and retrieval and its connectivity with an attention control network at encoding were associated with enhanced memory for realistic prices. Finally, older adults showed overactivation of control regions during retrieval of realistic prices relative to younger adults. Our findings suggest that DN activity and connectivity patterns (traditionally viewed as indicators of cognitive failure with age), and additional recruitment of control regions, might underlie older adults' enhanced memory for meaningful associations.
证据表明,对于与先前知识一致的联想,年龄差异在联想记忆中会减弱。这些知识结构传统上与默认网络(DN)有关,DN 也随着年龄的增长而减少调节。在本研究中,我们调查了 DN 活动和连接模式是否可以解释这种与年龄相关的影响。年轻和年长的成年人在学习常见杂货的真实和不真实价格时接受了功能磁共振成像。两组在对真实价格进行编码时,DN 的活动都比不真实价格更高。此外,在编码和检索时的 DN 活动及其与注意力控制网络在编码时的连接与真实价格的记忆增强有关。最后,与年轻成年人相比,年长成年人在检索真实价格时控制区域的过度激活。我们的研究结果表明,DN 活动和连接模式(传统上被视为与年龄相关的认知失败的指标)以及对控制区域的额外招募,可能是年长成年人对有意义的联想增强记忆的基础。