The spatial distribution of inhibition of return

Inhibition of return (IOR) refers to the finding that response times (RTs) are typically slower for targets at previously attended (cued) locations th an for targets at navel (uncued) locations. Although previous research has indicated that IOR may spread beyond a erred location, the present study is the first to examine the spatial distribution of IOR with high spatial res olution over a large portion of the central visual field. This was done by using a typical IOR procedure (cue, delay, target) with 4 cue locations and 441 target locations (each separated by 1 degrees of visual angle). The re sults indicate that IOR spreads beyond the cued location to affect the cued hemifield. However, the cites also produced a gradient of RTs throughout t he visual field, with inhibition in the cued hemifield gradually giving way to facilitation in the hemifield opposite the cue.