BRIGHTNESS AND BRIGHTNESS RATIO AS FACTORS IN THE ATTENTION VALUE OF HIGHWAY SIGNS

BY MEASURING THE SUBJECTIVE REACTIONS AND EYE MOVEMENTS OF SUBJECTS LOOKING AT PAIRS OF NEUTRAL GRAY CHIPS VARYING IN EITHER BRIGHTNESS, BRIGHTNESS RATIO, OR BRIGHTNESS AND BRIGHTNESS RATIO, IT WAS POSSIBLE TO ASSESS THE ROLE OF THESE PARAMETERS IN ATTENTION VALUE. EACH VARIABLE CONTROLLED ATTENTION WHEN COMPOUNDED. WHEN THE TWO PARAMETERS VARIED SUMULTANEOUSLY, BRIGHTNESS RATIO PREDOMINATED, BUT A HIGH BRIGHTNESS ENHANCED THE ATTENTION- GETTING VALUE OF HIGH CONTRAST. THIS WAS MORE EVIDENT IN THE NEGATIVE THAN IN THE POSITIVE CONTRAST DIRECTION. IT IS SUGGESTED THAT ADDITION OF A FACTOR CONSIDERING HIGH RELATIVE BRIGHTNESS IN COMBINATION WITH HIGH RELATIVE BRIGHTNESS RATIO WOULD REFINE THE FORBES ET AL MODELS OF HIGHWAY SIGN ATTENTION VALUE. /AUTHOR/