KembaraXtra-Psychology - Aubert effect
The Aubert effect occurs when a person fixates on an illuminated vertical bar in a dark room for a minute or two and then tilts the head sideways by roughly 30 degrees or more; the bar then appears tilted in the opposite direction. This demonstrates that vestibular semicircular canal information alone is insufficient for full vertical orientation in darkness, and it can be demonstrated using a simple setup such as a flashlight in a box with a diffusing slit. It is named after Hermann Aubert (1826–92).