Soutschek Alexander, Taylor Paul C J, Schubert Torsten
Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany.
Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich, Blumlisalpstrasse 10, 8006, Zurich, Switzerland.
Exp Brain Res. 2016 Sep;234(9):2447-55. doi: 10.1007/s00221-016-4649-x. Epub 2016 Apr 15.
When humans perform two tasks simultaneously, responses to the second task are increasingly delayed as the interval between the two tasks decreases (psychological refractory period). This delay of the second task is thought to reflect a central processing limitation at the response selection stage. However, the neural mechanisms underlying this central processing limitation remain unclear. Using transcranial magnetic stimulation (TMS), we examined the role of the dorsal medial frontal cortex (dMFC) in a dual-task paradigm in which participants performed an auditory task 1 and a visual task 2. We found that dMFC TMS, relative to control conditions, reduced the psychological refractory period for task 2 processing, whereas we observed no dMFC TMS effects on task 1 processing. This suggests a causal role of the dMFC in coordinating response selection processes at the central bottleneck.
当人类同时执行两项任务时，随着两项任务之间的间隔时间缩短，对第二项任务的反应会越来越延迟（心理不应期）。第二项任务的这种延迟被认为反映了反应选择阶段的中枢处理限制。然而，这种中枢处理限制背后的神经机制仍不清楚。我们使用经颅磁刺激（TMS），在一个双任务范式中研究了背内侧前额叶皮层（dMFC）的作用，在该范式中参与者执行听觉任务1和视觉任务2。我们发现，相对于对照条件，dMFC TMS缩短了任务2处理的心理不应期，而我们未观察到dMFC TMS对任务1处理有影响。这表明dMFC在中枢瓶颈处协调反应选择过程中起到了因果作用。
