人类工作记忆的某些神经影像研究

SOME NEUROIMAGING STUDIESONHUMAN WORKING MEMORY

采用神经影像技术研究人类工作记忆的脑机理是目前一个十分活跃的研究领域。研究表明存在负责不同信息加工的工作记忆系统 ,如词语工作记忆、空间工作记忆等 ,其中词语工作记忆主要由大脑左半球参与 ,空间工作记忆主要由大脑右半球参与。前额叶在工作记忆中的作用相当复杂 ,包括对记忆信息的注意和抑制、管理、整合等功能。合理巧妙的实验设计、多种研究手段的综合应用必将使人类工作记忆的脑机理得到充分阐明。

Working memory refers to a brain system that maintain a limited amount of information in an active state for a brief of time and manipulate that information necessary for such complex cognitive tasks as language comprehension, learning, and reasoning. Neuroimagingstudies on neural basis of human working memory indicated that: (1) there are different working memory systems with distinct neural implementation for verbal (localized more in the left hemisphere), spatial (localized more in the right hemisphere), visual or object information, and integrated information (localized in the right frontal lobe) ; (2) each system has three different functional components: (i) a pure storage component (localized more in the back of the brain), whose contents decay rapidly; (ii) a rehearsal component (localized more in the front of the brain), that can reactivate the rapidly decaying contents of the storage component; and (iii) an executive component (localized in the prefrontal cortex) that regulates the processing of the contents of working memory; (3) Prefrontal cortex plays an important role in both executive processes, such as attention and inhibition, task management, and integration of verbal and spatial information in working memory.