Saccades Follow Perception When Judging Location.

An unresolved question in vision research is whether perceptual decision making and action are based on the same or on different neural representations. Here, we address this question for a straightforward task, the judgment of location. In our experiment, observers decided on the closer of two peripheral objects-situated on the horizontal meridian in opposite hemifields-and made a saccade to indicate their choice. Correct saccades landed close to the actual (physical) location of the target. However, in case of errors, saccades went in the direction of the more distant object, yet landed on a position approximating that of the closer one. Our finding supports the notion that perception and action-related decisions on object location rely on the same neural representation.