The Speed and the Accuracy of a Perceptual Judgmentdepend on the Strength of the Sensory Stimulation. When Stimulus Strength Ishigh, Accuracy Is High and Response Time Is Fast; When Stimulus Strength Islow, Accuracy Is Low and Response Time Is Slow. Although the Psychometricfunction Is Well Established As a Tool For Analyzing the Relationship Betweenaccuracy and Stimulus Strength, the Corresponding Chronometric Function For Therelationship Between Response Time and Stimulus Strength Has Not Received Asmuch Consideration.