Effects of up-down visual inversion on motor skills.

The movement of a hand or fingers and locomotion of the body by a subject wearing prisms which inverted his visual world were investigated. A subject wore frame-spectacles (without prisms) for the first two days and then wore up-down inverting spectacles (with prisms) for the next four days, followed by wearing the former frame-spectacles again for one day. Measurements were made of skill on star-drawing, pegboard tests, and on zigzag-walking and walking up and down stairs. There were no differences on the five measures during acquisition for the four tasks, which suggests smooth progress of prism-adaptation by this man.