Abstract
Visual stimulation is continuous, yet we experience time unfold as a sequence of discrete events. A great deal of work has explored the consequences of such event segmentation on perception and attention, but this work has rarely made contact with higher-level thought. Here we bridge this gap, demonstrating that visual event boundaries can eliminate one of the most notorious (and stubbornly persistent) biases in decision-making. Subjects viewed an immersive 3D animation in which they walked down a long virtual room. During their walk, some subjects passed through a doorway, while for others there was no such event boundary -- equating the paths, speeds, and overall room layouts. At the end of their walk, subjects encountered an item (e.g. a suitcase on the floor) and were asked to estimate its monetary value. The other critical manipulation was especially innocuous, not appearing to be part of the experiment at all. Before the online trial began, subjects reported the two-digit numerical value from a visually distorted 'CAPTCHA' ("to verify that you are human") -- where this task-irrelevant 'anchor' was either low (e.g. 29) or high (e.g. 92). In the no-doorway condition, we observed the well-known anchoring effect: value estimates were higher for subjects who encountered the high CAPTCHA value. Anchoring is especially difficult to resist (even with enhanced motivation, forewarning, and incentives), but remarkably, anchoring was eliminated in the doorway condition. Further experiments replicated this effect in multiple independent samples (and with other objects), showed that it does not depend on explicit memory for the initial anchors, and confirmed that it was due to the event boundary per se (and not to superficial differences such as the visual complexity of the room with and without a dividing wall). This demonstrates how subtle aspects of visual processing can really *matter* for higher-level decision-making.