Abstract
When a test is flashed on top of two superimposed, opposing motions, the perceived location of the test is shifted in opposite directions depending on which of the two background motions is attended. A transparent layer that was composed of black splotches rotated in one direction, while the transparent layer that was composed of white splotches rotated in the opposite direction. Rotation direction reversed for both transparent layers simultaneously every 1200 ms. The test disks were in fact always vertically aligned, and appeared for ∼50 ms starting at the moment when the white transparent splotch layer began rotating CW and the black transparent splotch layer started rotating CCW. When the white splotch layer was attended, the disk pair appeared slanted to the right. When the black splotch layer was attended, the disk pair appeared slanted to the left. Because the stimulus remains unchanged as attention switches from one motion to the other, the effect cannot be due to stimulus-driven, low-level motion. A control condition ruled out any contribution from possible attention-induced cyclotorsion of the eyes. This provides the strongest evidence to date for a role of attention in the perception of location, and establishes that what we attend to influences where we perceive objects to be.