Keeping perception accurate

Perception should change if an error in perception is detected. Yet how can information that comes through the senses ever indicate that those very Se nses-aren't aceurate? Knowledge of objects that arises independently of sen sory experience can be used to check the sensory information for errors. Fo r instance, an a priori constraint that one object cannot be in two places at the same time would lead to error detection if,the sensory systems sugge st that one object is in two places. Variants on the classic prism-adaptati on phenomenon have revealed new rules about changes in space perception. th ese variants involve specifying new unusual mappings between visual space a nd motor (proprioceptive) space, and testing for generalization to novel un trained locations. The research has suggested that there is a preference fo r changes in space perception that shift space rigidly everywhere, that shr ink or expand space uniformly, and that preserve the one-to-one relationshi p between modalities. Finally, this review discusses the issue that percept ion must change to remain:accurate in the face of childhood growth and adul t drift.