Stimulus parameters in detection and reaction time.

This paper describes the relationship between detection threshold and reaction time for pure tones presented within the context of a two-interval forced-choice signal detection paradigm. Three variables manipulated were stimulus frequency (500 and 4,000 Hz), duration (50 and 300 ms) and rise/decay time for the longer stimulus (10 and 100 ms). The data for three practised, normal-hearing subjects indicated that stimulus energy was a good predictor of the detection threshold. Threshold measurements decreased as a function of the increase in stimulus duration and the decrease in rise/decay time. Both correct and incorrect reaction times also decreased with the increase in duration but were insensitive to a change in rise/decay time. The non-monotonicity of the function relating threshold and reaction time, as well as wide differences in reaction time for the same level of hearing acuity across subjects, led to the major conclusion that the two psychophysical measures were not interchangeable.