A new method for recovering superposed waveforms when the evoked-response is longer than the interval between stimuli has been recently invented. The new method is called QSD (q-Sequence Deconvolution). QSD can recover brain responses not previously observed because standard evoked-response technique is limited to responses shorter than the period of the stimulus repetition-rate. This project will build a visual stimulator for recording superposed VEPs (Visual Evoked Potentials). The project will then test whether the VEP responds at stimulus repetition-rates, which overlap the VEP. If it does, then the potentials may differ from those seen at slower stimulation rates. The project will also test whether stimuli more complex than checkerboards provide any additional measure of brain function. This project is health related because evoked-responses are widely used for screening and diagnostic testing. If the stimulator provides previously-unrecorded VEPs, then it is possible that such potentials could be of scientific and clinical use. Because the potentials are obtained from scalp electrodes it is easy to utilize such evoked-responses for clinical testing