前额叶皮层与双任务加工执行功能

Prefrontal Cortex with Executive Functions Involved in Dual-Task Performance

执行功能是完成复杂行为的先决条件,双任务加工为探究执行功能的经典范式之一。通过对双任务加工执行功能定位研究发现,前额叶皮层在双任务执行过程中占据核心地位。经典双任务范式包括行为双任务范式和交叠双任务范式。前额叶皮层(prefrontal cortex,PFC)为双任务加工执行功能定位相关脑区,主要表现为具有特定区域和激活程度改变两种观点,且前额叶皮层的三个子区域——额极皮层(frontopolar cortex,FPC)、内侧前额叶皮层(medial frontal cortex,MFC)和外侧前额叶皮层(lateral prefrontal cortex,LPFC)——在双任务执行过程中发挥着不同的作用。其中FPC主要与协调子任务加工有关;MFC根据动机线索对任务设置形成奖励预期;LPFC主要负责对任务设置规则进行选择和表征。介绍了双任务加工的神经计算模型,形象的揭示了前额叶皮层如何参与双任务执行过程。今后应进一步根据研究目的采用更适合的双任务范式并改进已有的分析方法,对双任务加工的执行功能进行更为深入的探讨。

Executive functions are believed to be a prerequisite for complex human behavior. Dual-task performance is one classical paradigm to investigate executive functions. The localization of executive functions in dual-task performance identified the prefrontal cortex （PFC） as related to dual-task performance Behavioral dual-task paradigms and over lapping dual tasks were included in the classical dual-task paradigms. The prefrontal cortex was a novel area specialized involved in dual-task executive processes, which including two opinions： additional activation in the PFC and a different magnitude of activation between dual- and single task. The three sub-regions of PFC - frontopolar cortex （FPC）, medial frontal cortex （MFC）, lateral prefrontal cortex （LPFC） - were played different role in dual task performance. FPC is relation to cooperate subtasks; MFC code for the reward expected according to motivation clues; LPFC are involved in selecting and maintaining action selection rules. Meanwhile, a neurocomputational model was introduced, showing that how the PFC involved in dual task executive processing. Further research should adopt more suitable paradigm according to experimental purposes and improve the existing analysis methods, and further discussion on executive function of dual-task performance should be employed.