Distractive effect in multiple-object tracking task / 中国组织工程研究

ABSTRACT

BACKGROUND: Research on selective attention of mobile visual information is relatively scarce because of difficulties in technology, methodology and experimental condition control. As is well known, most visual information in the real world is mobile and changeable. To examine the mechanism of mobile visual information is helpful to designing natural and highly efficient human-computer interface as well as selecting specialized personnel in special fields OBJECTIVE: To explore the distractive effect of the number, color, and form changes of distractors on multiple-target tracking performance. DESIGN: The present study was a 3 × 2 × 2 within subject design. Participants were undergraduates from Beijing Normal University.SETTING: Institute of Cognitive Neuroscience and Learning, Beijing Normal University.PARTICIPANTS: The experiment was performed in the Experimental Psychology Lab of Beijing Normal University in April 2003. Twenty-four undergraduates from Beijing Normal University participated in the experiment. Among them there were 11 males and 13 females aged 17-25 years.They all reported normal or corrected-to-normal vision and normal color perception.METHODS: ① Stimuli were presented on a 17-inch Founder monitor with the resolution of 1028 × 800 pixels. A Founder computer controlled the stimulus presentation and randomization of trials. Response latencies were collected by keyboard response with accuracy of one millisecond. The stimuli were randomly moving "日" characters. The number of "日" characters is 4, 8 and 12. As the participants were tracking the objects, the targets would transform to "(│)" and "(│)", and the distractors would change to "(│)" , "(│)", or "H" by removing lines from "日 ". All distractors and targets were red at the beginning of moving. ② The correct responses were analyzed with 3-factor repeated measures analysis of variance, multiple comparison analysis, and pairwise T-test.MAIN OUTCOME MEASURES: Response time and accuracy of pressing the keys.RESULTS: The data of 24 participants were involved in the final statistical analysis. ① The three-factor repeated measures ANOVA results showed that the main effect of the number change of distractors was significant [F(1,22)=6.040, P ＜ 0.05]. The further ANOVA and pairwise comparison in different experiment conditions also showed no distractive effects when target and distractor had different shape but the same color [F(1,2,3)=9.965, P ＜ 0.01]. The further pairwise comparison indicated that when the number of distractors was 2 and 6, the participants' response latencies had no significant effects, and they had significant effect when the number of distractors was 2 and 10, or 6 and 10 (RT10-RT2=46 ms, P ＜ 0.05, two-tail test; RT10-RT6=28ms, P ＜ 0.05, one-tail test). These results showed that the increase in the number of distractors had distractive effects. ② There had no significant effect whether target and distractor had the same color or not, when the number of distractors was 2 and 10. And there had significant effects whether the color of target and distractor was the same or not when the number of distractors was 6; the same shape of target and distractor produced distractive effects (Tsame colons=1.926; Tdifferent colons=2.044,P ＜ 0.05, one-tail test). The main effect of the color was not significant. The further pairwise comparison showed the same result. That is,the color change of diatractors had no obvious distractive effect.CONCLUSION: ① There was distractive effect when the number of distractors increased while the shape and color of distractor and target were different. ② There was no distractive effect when the number of distractors increased while the shape of distractor and target was the same. ③ There was distractive effect when the number of distractors increased while the shape of distractor and target was different, and there was distractive effect when the color of distractor and target was the same.