图画优异性效果在编码和提取中的促进作用

Facilitative Effect of the Picture Superiority Effect During Encoding and Retrieval

为调查图画优异性效果,比较了在编码和提取过程中图词和单词所诱发的ERP(事件相关电位)。20位中国留学生被分成2组,分别参加了图词和单词记忆实验,每个实验包含12个学习-测试序列。在图词记忆实验中,120幅图词组合被平均分成12组作为视觉刺激物呈现在学习阶段,相同的120个单词呈现在单词记忆实验的学习阶段。在两个实验的测试阶段,都只呈现单词作为记忆测试的刺激物,每个序列里随机呈现5个旧单词和5个新单词。在学习阶段,图词诱发的FN400比单词诱发的FN400波幅更大且持续时间更长。在提取阶段,相对于单词条件,图词条件的旧项目诱发了更显著的FN400熟悉性效果和晚期新旧效果。比较图词条件的新旧项目在提取阶段的ERP成分,发现图词旧项目诱发了显著的FN400熟悉性效果和晚期新旧效果。但在提取阶段,单词条件的新旧项目之间不存在显著的FN400波幅和晚期正成分波幅上的差异。因此推测,由于图词同时进行的图像和语义双编码引起了图词旧项目在测试阶段被更快更好地回忆,图画优异性效果主要表现为图画能增强编码和促进回忆。

In order to investigate the picture superiority effect, the event-related potential（ERP） is compared between the words combined with pictures （in the picture-word condition） and the pure words （in the word condition） during encoding and retrieval. Twenty Chinese oversea students are divided into two groups to participate in the two experiments, respectively. Each experiment consists of 12 sets of study-test. In the study phase of the picture-word memory experiment, 120 unambiguous line drawings of common objects combined with their Japanese nouns as stimuli are presented and are divided into 12 blocks of 10 items each, the same 120 Japanese nouns as stimuli are used in the study phase in the word condition. One test block includes 5 old （previously seen at the study phase） and 5 new items. The task of the subject is to memorize the presented stimuli at the study phase. At the test phase, the subject answers ＂Yes＂ or ＂No＂ if he/she thinks the stimulus is seen or not at the study phase. Comparing the ERP components between the two conditions during encoding, FN400 has greater amplitude and lasts longer under the picture-word condition than under the word condition, and shows a frontal-central scalp distribution predominance, reflecting that the image encoding of the abundant perceptual information of picture is activated the frontal-central sites. The late positive component （LPC） has more positive portion and distributes broadly under the word condition than under the picture-word condition, which can be interpreted in this way： the greater LPC might be related to the much active verbal encoding of words. During the retrieval, considering the ERP components elicited by old items between the two conditions, the FN400 amplitude is much smaller and the LPC amplitude is much greater under the picture-word condition than under the word condition, reflecting the fact that with old words the picture-word condition elicits remarkably FN400 familiarity effect and the parietal old/new effect as compared to the word condition. In the picture-word condition, the P300 amplitude and LPC amplitude are greater, and the FN400 amplitude is smaller for old items than for new items.These results demonstrate that old terms under the picture-word condition not only elicit a remarkably FN400 familiarity effect but also elicit a significant parietal old/new effect. On the other hand, under the word condition, we fail to find a better FN400 familiarity effect and parietal old/new effect for old words. It is suggested that simultaneous image and verbal encoding under the picture-word condition elicit better and faster recollection ＂than under the word condition during the memory test. The results demonstrate that the picture superiority effect is related to the ability of pictures enhancing encoding and facilitating recollection.