Abstract

A complete description of contrast perception includes threshold and suprathreshold contrast capabilities. Contrast matching methods provide relationships between apparent and physical suprathreshold contrast across spatial frequencies. Test charts for measuring threshold levels of contrast are available; however, suprathreshold measurements require time-consuming complex, and expensive computer driven display systems. We present a rapid, valid, and reliable contrast matching chart called the suprathreshold contrast test system (SCTS). The validity of the SCTS was determined by comparing contrast matching estimates on the chart with those obtained using three video display techniques: the method of adjustment, spatial two-alternative forced- choice, and temporal two-alternative forced- choice. Results suggest that the SCTS chart measures the same underlying neural mechanisms as those measured using the common psychophysical procedures. The reliability of the chart was also measured. Stability of measurements was found in the trial-to-trial correlations implying that the charts’ data does not change with repetitions.

© 1991 Optical Society of America