Time Course Of Inhibition Of Return

Inhibition of return(IOR) is a phenomenon that subjects are slower to respond to targets that appear at previously cued locations than to those at uncued locations. Among many researches on IOR, the time course of IOR is always being a critically theoretical issue. Our study measured the time course of IOR with the technology of Steady-state visual evoked potentials(SSVEP) for its high time precision and real-time monitoring features. The present study gave the real-time chart of IOR. Consistent with the previous studies, there existed a facilitation effect in cued condition after 200 ms cue onset, but when the time increased to greater than 200 ms the former facilitation effect was substituted by an inhibition effect. In addition, we compared the cued and the uncued condition, and the result suggested that no significant difference was discovered in the amplitude of SSVEP at the late stage(800 ~ 1400 ms), which implied that there might be an other mechanism of late IOR.