Rose Nathan S, Craik Fergus I M, Buchsbaum Bradley R
University of Wisconsin-Madison.
J Cogn Neurosci. 2015 Mar;27(3):522-32. doi: 10.1162/jocn_a_00738. Epub 2014 Oct 14.
How does the brain maintain to-be-remembered information in working memory (WM), particularly when the focus of attention is drawn to processing other information? Cognitive models of WM propose that when items are displaced from focal attention recall involves retrieval from long-term memory (LTM). In this fMRI study, we tried to clarify the role of LTM in performance on a WM task and the type of representation that is used to maintain an item in WM during rehearsal-filled versus distractor-filled delays. Participants made a deep or shallow levels-of-processing (LOP) decision about a single word at encoding and tried to recall the word after a delay filled with either rehearsal of the word or a distracting math task. Recalling one word after 10 sec of distraction demonstrated behavioral and neural indices of retrieval from LTM (i.e., LOP effects and medial-temporal lobe activity). In contrast, recall after rehearsal activated cortical areas that reflected reporting the word from focal attention. In addition, areas that showed an LOP effect at encoding (e.g., left ventrolateral VLPFC and the anterior temporal lobes [ATLs]) were reactivated at recall, especially when recall followed distraction. Moreover, activity in left VLPFC during encoding, left ATL during the delay, and left hippocampus during retrieval predicted recall success after distraction. Whereas shallow LOP and rehearsal-related areas supported active maintenance of one item in focal attention, the behavioral processes and neural substrates that support LTM supported recall of one item after it was displaced from focal attention.
大脑如何在工作记忆(WM)中维持待记忆信息,尤其是当注意力焦点被吸引去处理其他信息时?工作记忆的认知模型提出,当项目从焦点注意力中被替换时,回忆涉及从长期记忆(LTM)中检索。在这项功能磁共振成像(fMRI)研究中,我们试图阐明长期记忆在工作记忆任务表现中的作用,以及在充满复述与充满干扰物的延迟期间用于在工作记忆中维持一个项目的表征类型。参与者在编码时对单个单词做出深加工或浅加工水平(LOP)的决策,并在经过一段延迟后尝试回忆该单词,延迟期间要么是对该单词的复述,要么是一项干扰性的数学任务。在10秒的干扰后回忆一个单词显示出从长期记忆中检索的行为和神经指标(即加工水平效应和内侧颞叶活动)。相比之下,复述后的回忆激活了反映从焦点注意力中报告该单词的皮质区域。此外,在编码时显示出加工水平效应的区域(例如左腹外侧前额叶皮层[VLPFC]和前颞叶[ATL])在回忆时被重新激活,尤其是当回忆发生在干扰之后。此外,编码期间左VLPFC、延迟期间左ATL和检索期间左海马体的活动预测了干扰后回忆的成功。虽然浅加工水平和与复述相关的区域支持在焦点注意力中对一个项目的主动维持,但支持长期记忆的行为过程和神经基质支持一个项目从焦点注意力中被替换后的回忆。