通过三个实验考察了图像记忆对动态搜索的影响。实验1对静态和限制动态条件下的搜索效率进行比较,以进一步检验视觉搜索的无记忆模型;实验2通过比较限制动态和动态条件下的搜索效率,考察了图像记忆在动态搜索中对注意的引导作用;实验3考察了视觉搜索中新客体优势对搜索效率的影响。结果发现:(1)在静态和动态条件下,视觉搜索中均有记忆参与,但两种条件下的搜索模式不同;(2)在动态搜索中,每当画面变化时被试可依据图像记忆将注意指向可能出现目标的新位置,从而提高搜索效率;(3)视觉搜索中新客体优势不显著,这提示搜索过程中的注意指向主要受图像记忆的引导。
The role of memory in visual search has become a controversial issue. Most theories of serial visual search support the view that visual search requires memory and a serial scanning mechanism, such as the processes of inhibition of return in serial search (Klein, 1988). However, Horowitz and Wolfe (1998) claimed that serial visual search worked without memory. They compared the search rates in both static and randomly dynamic conditions that prevented parallel accumulation of information of a particular letter and found no significant difference between the two conditions. In the present study, iconic memory was examined in dynamic conditions. Besides, the new object advantage was tested to explain the outcome of Wolfe’s study. In experiment 1 a comparison was made between two conditions: In the restrained dynamic condition, the items moved to positions previously occupied by other items every 110ms. In the static condition, the display items remained in the same location from one frame to the next. In experiment 2 a comparison was made between a restrained dynamic condition and a random condition, in which the items moved to positions not occupied by any item in the last frame. In experiment 3, half of the items moved to new locations and half randomly moved to ones previously occupied. This experiment compared two conditions: the target moving to new locations and the target moving to old locations where items appeared in the last frame. Different groups of students participated in the experiment 1,2 and 3, 10, 14, and 12 students, respectively. In all experiments, the number of letters in the display (set-size) varied between 8, 12, and 16. The slope of the target-present reaction time × set-size function was used to measure the efficiency of display search. Repeated measures ANOVA and linear regression were used to analyze the data. The main results of this study were as follows: first, the efficiency of search under static conditions was significantly higher than that under restrained dy