When shape information from a foveal nontarget affects gap detection accuracy in a parafoveal target.

Abstract

Effects on gap detection accuracy of information at fixation concerning a parafoveally presented target form's global shape were determined in three experiments. Shape information was not directly relevant to the correct response regarding the presence of the gap. Tests were conducted to determine whether costs and benefits were associated with shape information, whether the effectiveness of shape information was sensitive to spatial attention, and whether subjects could volitionally suppress the nontarget information if it became apparent from preattentive analysis that it would not be helpful. Results were positive in all instances. Conclusions were that the foveal information was subject to early selection and that therefore it was not processed automatically.