On the causes and effects of inhibition of return

Unpredictive visual transient cues have a biphasic effect on reaction times (RTs) to peripheral onset targets. At relatively short (e.g., 150-msec) cu e-target stimulus onset asynchronies (SOAs), RTs to targets at cued versus uncued locations are facilitated, whereas at relatively long SOAs (e.g., be yond 300 msec), they are inhibited. The present review explores the conditi ons under which this latter, inhibitory, effect-referred to as inhibition o f return (IOR; Posner & Cohen, 1984)-is revealed and those conditions under which it is generated. We argue that the extant literature converges on th e view that IOR reflects a motor response bias that is generated by the act ivation of an oculomotor program to fixate the cue. However, we reveal that current conceptualizations of IOR are based on a limited sampling of possi ble tests of the generation and measurement of IOR and indicate where furth er experimental research is critical.