A realization of dynamic random-dot stereograms for cortical stereoscopic VEP on the IBM PC

In order to assess stereopsis objectively by visual evoked potentials (VEP) measured at the human scalp, dynamic random-dot stereograms (RDS) were generated online on an IBM PC. The stimulus, a rectangular area of certain size with binocular disparity different from its surrounding, was perceived in depth when viewed with a stereoscope (binocularly). Monocularly, only a continuous 'snowstorm' just like dynamic TV noise could be perceived. The whole procedure of dynamic RDS generation was controlled by software. No special hardware was required.<
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