Inhibition of return without return attention

Inhibition of Return (IOR) is in effect that consists of faster reaction time (RT) in responding to locations where we have previously attended involuntarily. Posner & Cohen (1984) postulated that this effect is due to a mechanism that prevents reorienting attention to previously attended locations. Thus. IOR should be cancelled if the person Voluntarily maintains attention at the location where the target will appear. In this experiment we manipulated the target (which could be either cued or un-cued exogenously) to appear either in an expected or unexpected location. The results showed, opposed to Posner and Cohen's hypothesis, significant IOR in both expected and unexpected positions. Similar effects were observed with detection and discrimination tasks, but the temporal course was different, thus replicating the pattern of results observed by Lupianez, Milan. Tornay, Madrid y Tudela (1997).