Abstract: Two experiments on inhibition of return(IOR) were conducted using cue-target method with dual task. Simple distraction stimuli were used in the first experiment and complex ones in the second. They were given separately in cue-presentation Phase or / and target-presentation phase in both experiments. College students were tested. Their primary task was to detect the sign a * which appeared in either peripheral box and press corresponding key as soon as they caught the sign. The results showed: (1) There was still an IOR effect in the condition of simple distraction task, but the value of IOR decreased; yet IOR completely disappeared in the condition of complex distraction task. (2) The divided attention at different phase of the task had no difference in its effect on IOR The authors suggested that the results didn't support the attention-inhibited hypothesis and response-inhibited hypothesis. A new hypothesis was proposed that IOR may come from some kind of link between the activated perceptual representation and response.

Key words: divided attention, inhibition of return, dual task, interference, perceptual representation