Abstract: A person being tested looks into a mirror through which is exhibited on a surface displaced upwardly from the striking row a previously prepared sheet of paper inserted into a conventional typewriter. The path of viewing passes through a Dove prism or other optical system to rotate optically the material prepared in miniature on the paper. The prepared material may be in miniature letters, symbols, etc., and is viewed through a magnifying lens which permits clear visibility of the miniature material. The optical rotation permits the commands or stimuli on the paper to be prepared in a vertical orientation and yet be viewed in any surface orientation, notably as horizontal words, letters, or numbers. Other symbols, lines, shapes, designs, textures, pictures, or colors may also be used as commands. A clock is actuated with the subject's first response on a row and is stopped at completion of the row of typing.