Cueing of object orientation facilitates attentional selection of relevant objects.

Three experiments investigated the effects of advance information about orientation on the processing of relevant and irrelevant objects, as indicated by Stroop effects from color words located in either object. Four results were obtained. First, participants showed the expected modulation of the Stroop effect: words in the relevant object produced much larger Stroop effects than words in the irrelevant object or words in the background. Second, blocking of object orientation had no effects. Third, informative orientation cues facilitated processing of the relevant object, but cueing did not affect processing of the irrelevant object. Fourth, effects of informative orientation cues were restricted to the first part of each experiment. Results suggest that observers can use advance information about object orientation for improving attentional selection of a visual object. In addition, the results revealed some constraints for the effective use of orientation cues, and discard possible explanations for the observed modulation of Stroop effects.