Abstract: The effects of central and peripheral pre-cues on the detection of orientation and presence-absence was studied. The results indicated that the detection of presence-absence showed shorter RTs and lower error rates than that of orientation in both valid and invalid conditions for central and peripheral cues.Pre-cues affected the detection of orientation in terms of both RT and error rate,but they affected the detection of presence-absence only in terms of RT.The pre-cue effects on the detection of orientation were stronger than that of presence-absence.The present results did not support the possible explanation based on the difference of luminous flux of Han and Chen's[4] experiment,and gave more evidences for the differential effects of pre-cues on the detection of different geometric properties.

Key words: Attention, Precue, Local geometric property, Topological Property