背景颜色对一致性序列效应的调节

The Modulation of Background Color on Congruency Sequence Effect

背景颜色是一个重要的环境因素,大量研究表明背景颜色影响人的认知和行为表现。然而,背景颜色对认知控制的影响,是一个关键但又被忽略的问题。为了探讨清楚这个问题,本研究采用字母flanker任务,考察了灰色、蓝色和红色三种颜色背景条件下的一致性序列效应和干扰效应。结果发现,蓝色背景下的一致性序列效应不显著,而灰色和红色背景下均得到了显著的一致性序列效应。三种颜色背景均出现显著的冲突干扰效应,但它们之间没有显差异。这些结果表明,认知控制的在线调整受蓝色背景的干扰,冲突解决不受背景颜色的影响。本研究首次揭示了背景颜色对认知控制在线调整的影响,也进一步加深了我们对一致性序列效应的理解。

Cognitive control is essential for humans to adapt to the rapidly changing environment. Performance on congruency tasks has long been considered a useful model for probing cognitive control processing. In particular, the congruency sequence effect provides a direct window into ongoing adjustments in cognitive control. The congruency sequence effect refers to the interference effect being smaller after incongruent trials than after congruent trials in congruency tasks. Previous studies have indicated that the congruency sequence effects are influenced by subjective factors （e.g., motivation and emotion）. However, there is little research on the effect of direct environmental variables （e.g., environmental color） on the congruency sequence effect. Lines of research have suggested that color can exert influences on cognition and behavioral performance. Therefore, we speculated that the effect of background color on the ongoing adjustment of cognitive control is a critical but ignored issue. The present study employed the four-letter flanker task, which was presented by E-Prime software （Psychological Software Tools, Pittsburgh, PA, USA）, and investigated whether the congruency sequence effect was influenced by gray, blue, and red backgrounds. In each trial, a line of five letters was presented： the central one was the target, and the remaining letters were the flankers. Four letters （i.e., S, H, N, and P） were employed in the task, and each letter could be a target or a flanker. In the congruent trials, the flankers were identical to the target （e.g., NNNNN）, and in the incongruent trials, the flankers were mapped onto a different response hand to the target stimulus （e.g., SSNSS）. Participants were instructed to press the key corresponding to the central letter. Responses were made using one of the four different fingers （i.e., left middle finger, left index finger, right index finger and right middle finger）. The four responses corresponded to four keys （i.e., 1 key, 2 key, 9 key, and 0 key）. The flanker task consisted of three blocks. Each block was set as one color and comprised 192 trials. Stimuli were presented in a pseudorandom order in which the numbers of CC, CI, IC, and II trial sequences were counterbalanced. In order to control for repetition priming and feature integration effects, target and flanker stimuli were always alternated across trials. The order of a trial was as follows： After a 300 ms fixation displayed, followed by a random blank presented for 300-500 ms, the letter array was presented in the center of screen for 200 ms. A blank screen was presented for 1,500 ms, during which participants were instructed to press the corresponding key as quickly and as accurately as possible. After another random blank screen, lasting for 800-1,200 ms, the next trial started. The results showed that the background color type × previous trial ×current trial congruency repeated-measures ANOVA on RT data revealed a significant three-way interaction effect （p 〈 0.05）. The congruency sequence effects were significant on gray and red backgrounds （p 〈 .01;p 〈 .01）, however the congruency sequence effect was absent on a blue background （p 〉 .05）. Additionalty, we found that there were significant flanker interference effects across the three backgrounds （p 〈 .001;p 〈 .001 ;p 〈 .001）, but there was no significant difference between them （p 〉 .05）. These results suggest that the blue background affected the congruency sequence effect; however, the interference effect was not modulated by the background color. The present study, for the first time, reveals the impact of background colors on the ongoing adjustment of cognitive control and furthers our understanding of the congruency sequence effect.