visual evoked responses
visual evoked responsesA method of modifying the electroencephalogram by exposing the subject to visual stimuli. The most useful is a reversing chessboard pattern in black and white. The time taken after each reversal for the change to occur on the EEG is affected by defects of conduction along the optic nerves, tracts and radiations, such as may be caused by multiple sclerosis. Unlike visual acuity tests, the method is purely objective.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005