The appropriateness of luminance vs. energy as a descriptor of CRT stimulus output when measuring the temporal aspects of vision

Abstract

The use of cathode-ray-tube monitors is widespread in the vision science community. The temporal response of these displays is, however, known to vary with the frame rate selected. No previous study has investigated if variations in frame rate impacts upon the temporal processing of spatially identical stimuli. In this study we found the upper limit of complete temporal summation for an achromatic spot stimulus to be greater at 60Hz compared with a frame rate of 160Hz when visual thresholds were classified using luminance output. No such variation was found when a novel metric quantifying total energy output was used. This finding has significant implications for the accurate quantification of visual thresholds collected using display monitors used in visual psychophysics investigations.