Abstract: Physiologists identified two types of neural pathway in visual cortical areas that represent color:a red green pathway and a blue yellow pathway. Thus there were different channels in color processing. The research studied whether dual task performance would be better when two tasks had different color coding. 32 Ss(16 females and 16 males,agd 20 23 years)were seated in front of a computer screen to complete two searching tasks with two hands simultaneously. Both stimuli were separately displayed on the left and right side of the screen one by one. Subjects were asked to search target words from a series of stimuli,which were made up of figure words,orientation words and strokes of Chinese character words. The target words of one task were figure words,another was orientation words. The color of two tasks had two conditions:red matched green and yellow matched blue. Each subject took part in one color condition experiment,that is,they should complete two kinds of experiment:two tasks with the same color and two tasks with different colors. The results of the data analysis found the following conclusions:(1) When the color of two tasks were different,the response time decreased,but when the color of two tasks were the same,the response time increased. It was proved that if there were different color coding modes for the current two tasks,the dual task performance would be improved because of the decrement of structure limitation. (2) The interference between information processing of the two tasks is a major source in dual task performance decrease. The higher the interference,the worse the dual task performance,so the stimuli for both tasks were not processed independently. This result supported the outcome conflict proposition and was the same as previous experiments. The experiment supported the three factor hypothesis of dual task performance.

Key words: dual task performance, structure limitation, color coding mode