Transsaccadic coding of object position: Effects of saccadic status and allocentric reference frame

When we move our eyes to examine new regions of interest in a visual scene, object position on the retina shifts and the question is raised whether an d how we keep track of an object's position across a saccade. Verfaillie an d colleagues (1997; Verfaillie & De Graef, 2000) demonstrated that transsac cadic memory for object position is poor, but can be improved when a strict ly egocentric reference frame is complemented by an allocentric reference f rame. When such a reference frame is available, the saccadic status of an o bject (i.e., saccade source vs. saccade target) appeared to have little eff ect on the accuracy of transsaccadic position coding, although there was so me indication that the saccade target benefitted most from allocentric codi ng. In the present paper, we systematically investigated the impact of allo centric reference frames on the accuracy of transsaccadic position memory f or saccade target, saccade source, and saccade bystander. In Experiment 1, the saccade target did indeed benefit most from being integrated in a trian gular object configuration, providing a distinctive allocentric reference f rame. In Experiment 2, we determined that this apparent allocentric target superiority was artifactual: When after-images due to phosphor persistence were eliminated, the saccade source proved to be the object that benefitted most from transsaccadic coding of its position in an allocentric reference frame. Together with the finding that bystander position was also maintain ed transsaccadically these data challenge theories which assume that the sa ccade-target region has a privileged role in keeping a transsaccadic record of a scene's spatial layout.