Abstract
A series of three experiments was undertaken to determine the role of prior knowledge of different movement cues in the preselection effect. Experiments 1 and 2 examined the singular and combinative role of location and extent cues under both preselected and constrained conditions. The third experiment provided a framework for evaluating the sources of information which may contribute to the preselection phenomenon. In experiments 1 and 2, the results suggest the advantage of preselected over constrained movement was constant across movement cues. The second experiment demonstrated that the dual cue condition was superior to location alone and extent alone in both accuracy and consistency. Finally, the third experiment indicated that prior knowledge (strategy) was the primary variable responsible for the preselection effect.