Groh-Bordin Christian, Zimmer Hubert D, Mecklinger Axel
Department of Psychology, Brain and Cognition Group, Saarland University, 66123 Saarbruecken, Germany.
Brain Res Cogn Brain Res. 2005 Aug;24(3):556-67. doi: 10.1016/j.cogbrainres.2005.03.006. Epub 2005 Apr 13.
It is argued that explicit remembering is based on so-called episodic tokens binding together all perceptual features of a visual object. In episodic recognition, these features are collectively reactivated. In support of this view, it has been shown that changing sensory features of a stimulus from study to test decreases subject's performance in an episodic recognition task, even though the changed features are irrelevant for the recognition judgment. On the other hand, repetition priming is unaffected by such manipulations of perceptual specificity. Implicit memory performance is therefore thought to depend on structural representations, so-called types, comprising only invariant perceptual features, but no exemplar-specific details. Event-related potentials (ERPs) in our study revealed electrophysiological evidence for the differential involvement of these perceptual memory traces in explicit and implicit memory tasks. Participants attended either a living-nonliving task or an episodic recognition task with visually presented objects. During test both groups of participants processed new objects and old objects, which were repeated either identically or in a mirror-reversed version. In the implicit task ERPs showed an occipitoparietal repetition effect, which was the same for identically repeated items and mirror reversals. In contrast, in the explicit task an early mid-frontal old/new effect for identical but not for mirror-reversed old objects was observed indicating involuntary access to perceptual information during episodic retrieval. A later portion of the old/new effect solely differentiated both types of old items from new ones.
有人认为,外显记忆基于所谓的情景标记,即将视觉对象的所有感知特征绑定在一起。在情景识别中,这些特征会被共同重新激活。支持这一观点的是,研究表明,将刺激的感觉特征从学习阶段改变为测试阶段会降低受试者在情景识别任务中的表现,即使改变的特征与识别判断无关。另一方面,重复启动不受这种感知特异性操作的影响。因此,内隐记忆表现被认为依赖于结构表征,即所谓的类型,仅包括不变的感知特征,而不包括示例特定的细节。我们研究中的事件相关电位(ERP)揭示了这些感知记忆痕迹在显式和隐式记忆任务中不同参与程度的电生理证据。参与者参与了一个生物-非生物任务或一个使用视觉呈现对象的情景识别任务。在测试期间,两组参与者都处理新对象和旧对象,旧对象要么完全相同地重复呈现,要么以镜像反转的形式呈现。在内隐任务中,ERP显示出枕顶叶重复效应,对于完全相同重复的项目和镜像反转的项目来说是相同的。相比之下,在显式任务中,观察到对于相同但不是镜像反转的旧对象有早期额中旧/新效应,这表明在情景检索期间会自动获取感知信息。旧/新效应的后期部分仅将两种类型的旧项目与新项目区分开来。