Relationship between amplitude of pattern displacement and visual evoked potentials.

Thirteen subjects looked at a 7 mm2 black and white checkerboard which was displaced through 0.25, 0.50, 0.75 and full pattern displacement. One hundred and twenty eight averages were taken for each displacement and the peak to peak amplitude of the visual evoked potential was measured. This showed a linear relationship between pattern displacement and size of the evoked potential. Latency was unaffected for 0.25, 0.50 and 0.75 displacement but was significantly longer for the full pattern stimulation.