一項研究發(fā)現(xiàn)了許多老年人面臨的同時執(zhí)行多重任務(wù)困難的神經(jīng)基礎(chǔ),。科研人員已經(jīng)認同,，隨著人們衰老,，許多人發(fā)現(xiàn)當一個新任務(wù)打斷了原來的任務(wù)時，原來的任務(wù)就很難完成,。Adam Gazzaley 及其同事使用了fMRI來找出參與一項多任務(wù)試驗的20名60歲以上受試者的這種缺陷的神經(jīng)基礎(chǔ),。這組作者然后把這些結(jié)果與此前進行的20位較年輕的受試者參與的一項類似實驗結(jié)果進行了比較。與較年輕的受試者相比,，老年受試者在識別曾在一個顯示器上展示給他們的自然場景方面的成功率更低,，此時他們也被要求執(zhí)行一個干擾任務(wù)，即報告在自然場景識別測試之前很短的時間里顯示出的一張臉的性別和大約的年齡。根據(jù)這些受試者大腦的兩個區(qū)域（視覺皮層和前額葉皮層）的連接模式,，這組作者提出老年人在多任務(wù)方面的成功率較低并不是因為他們把更多的注意力分配給了那個干涉任務(wù),，而是因為他們更難以擺脫那個干擾任務(wù)并重新激活最初的任務(wù)的神經(jīng)網(wǎng)絡(luò)。這組作者說,，特別是由于人們傾向于工作到更老,，這些發(fā)現(xiàn)在衰老對認知性能的影響方面有意義。（生物谷Bioon.com）
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.1015297108
Deficit in switching between functional brain networks underlies the impact of multitasking on working memory in older adults
Wesley C. Clapp, Michael T. Rubens, Jasdeep Sabharwal, and Adam Gazzaley1
Abstract
Multitasking negatively influences the retention of information over brief periods of time. This impact of interference on working memory is exacerbated with normal aging. We used functional MRI to investigate the neural basis by which an interruption is more disruptive to working memory performance in older individuals. Younger and older adults engaged in delayed recognition tasks both with and without interruption by a secondary task. Behavioral analysis revealed that working memory performance was more impaired by interruptions in older compared with younger adults. Functional connectivity analyses showed that when interrupted, older adults disengaged from a memory maintenance network and reallocated attentional resources toward the interrupting stimulus in a manner consistent with younger adults. However, unlike younger individuals, older adults failed to both disengage from the interruption and reestablish functional connections associated with the disrupted memory network. These results suggest that multitasking leads to more significant working memory disruption in older adults because of an interruption recovery failure, manifest as a deficient ability to dynamically switch between functional brain networks.
