The roles of prefrontal brain regions in components of working memory: Effects of memory load and individual differences
The roles of prefrontal brain regions in components of working memory: Effects of memory load and individual differences
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DOI：
10.1073/pnas.96.11.6558
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发表时间：
1999-05-25
影响因子：
11.1
通讯作者：
D'Esposito, M
中科院分区：
文献类型：
--
作者：
Rypma, B;D'Esposito, M
采用事件相关的功能磁共振成像设计，我们探讨了背侧和腹侧前额叶皮层（PFC）区域在不同的记忆负荷条件下的工作记忆任务的特定组件（编码，延迟，反应）的相对作用。在一组分析中，增加记忆负荷的影响，观察到只有在背侧PFC的编码期。在高记忆负荷条件下，大脑活动偏向右半球，而在低记忆负荷条件下则没有。个体分析揭示了受试者之间激活模式的变异性。回归分析表明，变异的一个来源是受试者的记忆提取率。据观察，背PFC发挥差异较大的作用，在信息检索较慢的科目，可能是因为效率低下的检索过程或质量降低的记忆表示。本研究支持了背侧和腹侧PFC在工作记忆各成分加工中发挥不同作用的观点。
Using an event-related functional MRI design, we explored the relative roles of dorsal and ventral prefrontal cortex (PFC) regions during specific components (Encoding, Delay, Response) of a working memory task under different memory-load conditions. In a group analysis, effects of increased memory load were observed only in dorsal PFC in the encoding period. Activity was lateralized to the right hemisphere in the high but not the low memory-load condition. Individual analyses revealed variability in activation patterns across subjects. Regression analyses indicated that one source of variability was subjects' memory retrieval rate. It was observed that dorsal PFC plays a differentially greater role in information retrieval for slower subjects, possibly because of inefficient retrieval processes or a reduced quality of mnemonic representations. This study supports the idea that dorsal and ventral PFC play different roles in component processes of working memory.