Working memory (WM) supports several higher-level cognitive abilities, yet we know less about factors associated with development and decline in WM compared to other cognitive processes. Here, we investigated lifespan changes in WM capacity and their structural brain correlates, using a longitudinal sample including 2358 magnetic resonance imaging (MRI) scans and WM scores from 1656 participants (4.4–86.4 years, mean follow-up interval 4.3 years). 8764 participants (9.0–10.9 years) with MRI, WM scores and genetic information from the Adolescent Brain Cognitive Development study were used for follow-up analyses. Results showed that both the information manipulation component and the storage component of WM improved during childhood and adolescence, but the age-decline could be fully explained by reductions in passive storage capacity alone. Greater WM function in development was related to apparent thinner cortex in both samples, also when general cognitive function was accounted for. The same WM-apparent thickness relationship was found for young adults. The WM-thickness relationships could not be explained by SNP-based co-heritability or by socioeconomic status. A larger sample with genetic information may be necessary to disentangle the true gene-environment effects. In conclusion, WM capacity changes greatly through life and has anatomically extended rather than function-specific structural cortical correlates.

工作记忆（WM）支持多种更高水平的认知能力，但与其他认知过程相比，我们对与工作记忆发展和衰退相关的因素知之甚少。在这里，我们使用纵向样本，包括 1656 名参与者（4.4-86.4 年，平均随访间隔 4.3 年）的 2358 次磁共振成像 (MRI) 扫描和 WM 评分，研究了 WM 能力的寿命变化及其大脑结构相关性。 8764 名参与者（9.0-10.9 岁）的 MRI、WM 评分和青少年大脑认知发展研究中的遗传信息被用于后续分析。结果表明，WM 的信息操作部分和存储部分在儿童期和青春期都有所改善，但年龄下降可以完全用被动存储能力的减少来解释。发育过程中更强的 WM 功能与两个样本中明显更薄的皮层有关，当考虑到一般认知功能时也是如此。对于年轻人也发现了相同的 WM-表观厚度关系。 WM-厚度关系不能用基于 SNP 的共同遗传力或社会经济地位来解释。可能需要包含遗传信息的更大样本才能解开真正的基因-环境影响。总之，WM 能力在一生中发生了很大的变化，并且在解剖学上具有扩展性，而不是功能特异性的结构性皮质相关性。