Before
computers became universal, tachistoscopes were used extensively in
psychological research to present visual stimuli for controlled durations. Some experiments employed pairs of tachistoscopes so that an experimental participant could be given different stimulation in each
visual field. Tachistoscopes were used during the late 1960s in public schools as an aid to increased reading comprehension for
speed reading. There were two types: the student would look through a lens similar to an aircraft bombsight viewfinder and read letters, words, and phrases using manually advanced slide film. The second type projected words and phrases on a screen in sequence. Both types were followed up with comprehension and vocabulary testing. Tachistoscopes continue to be used in market research, where they are typically used to compare the visual impact, or memorability of marketing materials or packaging designs. Tachistoscopes used for this purpose still typically employ slide projectors rather than computer monitors, due to • the increased fidelity of the image which can be displayed in this way and • the opportunity to show large or life-size images. == References ==