The experiment procedure is identical to that of the [previous experiment][1], with the following exceptions: * Because exclusion rates in the prior experiment were about 20%, we will recruit 500 subjects rather than 600 to achieve the desired 100 per condition. * The four conditions in this experiment, instead of varying near/far, will vary above/below. A subject will get a probe that appears close by, showing up either in front of them or behind them, and either slightly above them or slightly below them. The horizontal displacement of the probe is always 122 pixels in front or behind, and the vertical displacement is 122 pixels above or below. * Instead of being asked what side of the screen the unexpected object appeared on, subjects will be asked whether it appeared above or below their avatar. A demonstration version of the task with no data collection may be viewed [here][2]. [1]: https://osf.io/6rbsx/ [2]: http://simonslab.com/game/updown_demo.html