Three measures of adaptation were taken at half-hour intervals over two hours of exposure to a 20-deg counterclockwise prismatic tilt: a test of the visual vertical with goggles on (cue conditioning); one with goggles off; and a test of the proprioceptive vertical. The visual aftereffects measured with the goggles did not differ from those measured without. Significant proprioceptive changes and visual aftereffects occurred early in exposure, but the visual ones continued to grow with prolonged exposure while the proprioceptive ones did not.