A Methodological Investigation of Three Psychophysical Techniques for Rapid Measurement of Contrast Sensitivity

A general method for assessing visual capacity, contrast sensitivity function (CSF), has emerged in the last decade. The CSF describes visual detection of sine-wave gratings over a range of visual sizes. The purpose of this investigation was to compare the stability and sensitivity of three methods of obtaining rapid CSFs: Method of Adjustment (ADJ), Bekesy Tracking (B), and Method of Increasing Contrast (MIC). For each method, a microcomputer controlled video display was used to generate five different stationary gratings: 1, 2, 4, 8, and 16 cycles per degree (cpd). Individual contrast sensitivity functions were determined for each of 13 observers over five days. Analyses were conducted on reliabilities, means, and variances across frequencies, methods, and days. The MIC demonstrated near-largest or largest reliabilities over all frequencies across days. The MIC, in addition, appeared differentially stable from the onset of measurement (p > .10); while, both ADJ and B methods demonstrated differential instability (p < .002). The Methodof Increasing Contrast (MIC) may be recommended as the method of choice for assessing CSF based on the present findings.