Abstract: An experiment was conducted to examine the subsequent memory (Dm) effect of pictures. Fourteen graduates engaged in our experiment. In the present experiment, subjects viewed pictures of common objects under incidental learning conditions in which each picture required a two-choice decision based on semantic criteria (animal/nonanimal). Memory for those pictures was subsequently assessed by a free recall test and then a recognition test. Subjects were asked to recall the name of the pictures as many as possible in the free recall test. In recognition test, old pictures were mixed with new ones and subjects judged whether each picture was new or old. Data analysis indicated that：（1）Mean percent correct on recognition test was higher than on free recall test.（2）During encoding phase, Over the 400~700ms latency range, responses to remembered pictures were positive relative to responses of forgotten pictures. This Dm primarily distributed at frontal for free recall test and at central for recognition test. As a result, for Dm effect retrieval format is an important influence factor, and it was possible free recall and recognition rely on the different neurocognitive system.

Key words: subsequent memory effect, retrieval format, event-related potentials, pictures