tachistoscope
n. a device that displays (usually by projecting) visual material on a screen for a specific amount of time, usually at very brief intervals. Words, numbers, pictures, and symbols can be rapidly presented in the right or left visual field. The device is used in experiments concerned with visual perception, recognition speed, and memory. It is also widely used in market research concerned with advertising, logos, branding, and so forth. Also called T-scope.