Inhibition of return and visual search: how many separate loci are inhibited?

Using a novel sequential visual search paradigm Danziger, Kingstone, and Snyder (1998) demonstrated that inhibition of return (IOR) can reside at three spatial locations. In the present study, we extended the work of Danziger et al. by investigating whether there is a limit to the number of locations that can be inhibited in a sequential visual search task. Our study revealed that IOR can be measured at a minimum of five locations. The magnitude of the IOR effect was largest at the most recently searched location and declined from there in an approximately linear fashion. Two models that can account for our data are presented.