Inhibition of return to successively stimulated locations in a sequential visual search paradigm.

The inhibition of return (IOR) effect refers to a slowing in response time for a target that appears at a previously attended location. Many investigators have speculated that IOR's inherent ecological validity may be to ensure an efficient search of a complex environment by creating a bias against returning to locations that have already been investigated. Unfortunately, this intriguing idea has lacked compelling empirical support. The current study addressed this issue. It was shown that in a novel visual search task, the IOR could dwell at a minimum of 3 spatially noncontiguous locations. These data suggest that IOR may serve as an important mechanism for facilitating visual search in complex environments, by inhibiting attention from returning to previously inspected locations.