【作者】 荣亚朝； 郭春彦； 魏萍；

【Author】 Yachao Rong;Chunyan Guo;Ping Wei;Beijing Key Laboratory of Learning and Cognition and Department of Psychology,Capital Normal University;

【机构】 首都师范大学心理学院北京市"学习与认知"重点实验室；

【摘要】 已有研究认为,根据记忆内容的不同,工作记忆可以分为空间工作记忆、语义工作记忆和客体工作记忆,不同类型工作记忆的神经机制并不相同。本研究采用功能磁共振成像技术和延迟匹配样本任务(delayed match-to-sample task, DMT),探讨了客体的过去经验(学习过的和新的)与工作记忆中的客体样本进行匹配加工(匹配和不匹配)的神经机制。实验分为学习和延迟匹配两个阶段。在学习阶段,被试需要学习一系列的二维黑白客体图片(如摇篮)。在延迟匹配任务阶段,每个试次开始时同时呈现两张样本图片,随后连续呈现单独的12张测试图片。每个试次的两张样本图片均来自于学习过的客体图片或新的客体图片。被试的任务是判断每张测试图片是否与任意一张样本图片相匹配,并进行按键反应。延迟匹配任务阶段是在功能磁共振成像设备中进行的。行为结果表明,测试客体与样本客体不匹配条件的反应时慢于匹配条件的反应时,学习过的客体图片的反应时慢于新客体图片的反应时。神经成像结果表明,客体图片的过去经验在不同匹配条件下引起的双侧梭状回活动不同。新客体在匹配条件下引起的梭状回活动强于不匹配条件,而学习过的客体在两种条件下梭状回活动差异不显著。这表明工作记忆中客体信息的加工主要依赖于梭状回的客体表征,并会受到客体过去经验的影响。更多还原

【Abstract】 Working memory falls into three types: spatial WM, verbal WM and object WM, according to the contents of working memory, and the neural mechanisms of them was different. In present study, the functional magnetic resonance imaging(fMRI) technique and modified delayed match-to-sample task(DMT) was used to examine the neural correlates of identifying matched or nonmatched objects in WM and how this process was influenced by previous experience of these objects(studied or new). A set of two-dimensional objects were initially studied by participants before the DMT task. Each DMT trial in scanner began with the presentation of two sample pictures, which could be both studied objects or new objects, followed by 12 successive test pictures for participants to decide whether each test picture matched one of the sample pictures or not. Behavioral results showed slower reaction times(RTs) to nonmatches than to matches, and slower RTs to studied objects than to new objects. Neuroimaging results revealed that the activations of bilateral fusiform gyrus to matches and nonmatches were regulated by the past experience of these objects. Compared to new-nonmatches, new-matches elicited stronger activations in bilateral fusiform gyri; however, no differential activations were revealed for studied matches and studied nonmatches. These results indicated that the fusiform gyrus plays an important role in the processing of object WM, and the representations of objects information are strongly regulated by the previous experiences of these objects.更多还原