Computer monitor-based tachistoscopes (using a cathode ray tube, CRT) and conventional tachistoscopes differ in experimental control over stimulus continuity, duration, and timing accuracy. This study evaluated the perception of visual stimuli presented with the two different types of devices. An experiment was conducted to compare recognition of visuospatial stimuli (random shapes) presented laterally and centrally in the visual fields for short exposure durations (14, 29, and 43 msec), first with one device and then with another. Results indicated that the subjects' error rates and laterality patterns were similar on both types of tachistoscopes. It was concluded that perception of visual stimuli presented as continuous images on a conventional tachistoscope may be equivalent to perception of visual stimuli presented as pulsating images on a CRT. Further studies are needed using other types of visual materials to determine the range of visual stimuli for which both types of tachistoscopes measure equivalent perceptual processes.