ISSN 0439-755X
CN 11-1911/B

心理学报 ›› 2013, Vol. 45 ›› Issue (9): 935-943.doi: 10.3724/SP.J.1041.2013.00935

• 论文 •    下一篇



  1. (福建师范大学心理系, 福州 350007)
  • 收稿日期:2012-10-17 发布日期:2013-09-25 出版日期:2013-09-25
  • 通讯作者: 孟迎芳
  • 基金资助:

    全国教育科学规划教育部青年课题:对学业不良生信息编码与提取加工的脑机制研究(EBA090428); 福建省教育厅A类项目(JA11065S; JA09037)资助。

Neural Correlates at Encoding of Covert Face Recognition

MENG Yingfang   

  1. (Department of Psychology, Fujian Normal University, Fuzhou 350007, China)
  • Received:2012-10-17 Online:2013-09-25 Published:2013-09-25
  • Contact: MENG Yingfang

摘要: 为了探究内隐面孔再认在记忆形成过程中的认知加工状态, 该实验以陌生面孔为刺激, 采用事件相关电位(ERP)技术, 并结合相继记忆(Dm)范式和迫选再认测验, 把学习阶段的面孔分为相继记住、相继启动及相继忘记三类, 以相继记住与相继启动的ERP差异为外显记忆Dm效应, 以相继启动与相继忘记的差异为内隐记忆的Dm效应。结果表明, 内隐记忆表现为400~500 ms额中央区负走向的Dm效应, 可能反映了额叶皮层对信息的精加工过程, 而外显记忆表现为400 ms开始顶区正走向的Dm效应, 可能反映了记忆系统对加工后信息的自动登记过程。由此推测, 只有经过额叶加工并被内侧颞叶自动登记的信息, 随后才能被有意识地提取出来, 而未进入内侧颞叶的信息在随后测验中不可能产生有意识地记忆提取现象, 但储存的知觉表征可能触发微弱的记忆痕迹, 从而产生内隐面孔记忆。

关键词: 内隐面孔再认, 编码, Dm效应

Abstract: In everyday life, we encounter familiar and unfamiliar faces in many different environments. Many studies have demonstrated that face recognition is in fact a complex cognitive achievement. Although prosopagnosic individuals are severely impaired with explicit recognition of familiar faces, there have had substantial physiological and behavioral evidences for “covert face recognition”. Many evidences from event-related potential (ERP) investigations of brain activity with healthy participants have confirmed that covert face recognition and overt recognition have different neural bases at retrieval. But at encoding, the neural distinction between covert and overt face-related encoding processes is unknown. A powerful method of examining the neural basis of encoding is to measure neural activity during the study phase of an experiment and then to sort out these measurements according to subsequent memory test performance. ERP experiments employing intentional tests have typically shown positive deflection of waveforms recorded during study of faces that are subsequently recognized, comparing with waveforms recorded during study of faces that are subsequently unrecognized. The deflection is called “difference due to later memory” (DM) effect. However, DM effects for covert recognition in incidental tests have not been consistently observed, owing to methodological ambiguities in prior studies which often compared incidental tests with intentional tests. In fact, brain activity in one test can reflect not only covert but also overt recognition. So it is important to distinguish covert and overt recognition for specific episodes in one test. An experiment was conducted with subsequent memory paradigm and novel faces as stimuli. ERPs were recorded while participants were studying visually presented faces. The ERPs were sorted by whether or not participants would later recognized the studied face in a forced-choice recognition where two faces (one studied and one new) were presented concurrently, and by whether or not they would indicated that the choice was remembered from the study list. If they could not choose a studied face, subjects were encouraged to guess. Study trials from which the studied faces were later selected and remembered (remembered trials) were compared with those from which the studied faces were later selected and not remembered (primed trials), in order to measure the ERP difference (Dm effect) associated with later overt recognition. Primed trials were compared with study trials from which the studied faces were later not selected (forgotten trials), in order to measure Dm effect associated with later covert recognition. The results showed that comparing with forgotten trials, primed faces were associated with more negative waveforms at study over the frontal-central electrodes during 400~500 ms. This negative-going Dm effect was distinct from the positive-going Dm effect associated with later overt recognition by virtue of its polarity and topography, that is, comparing with the primed trials, remembered trials were associated with more positive waveforms at study over the parietal electrodes starting 400ms after face onset. We suggested that the negative-going Dm effect over the frontal-central electrodes could index the elaborated processing of encoding information into the perceptual representation system, and the positive-going Dm effect over the parietal electrodes could index the processing of encoding information into the episodic memory system. So only the stimuli which were encoded into the episodic memory system could be retrieved consciously during a later test. If the stimuli were not encoded into the episodic memory system, rather, they were encoded into the perceptual representation system by the elaborated processing, then minimal activation of corresponding memory traces would be triggered during tests, which could give rise to covert recognition.

Key words: covert face recognition, encoding, Dm effect