The absolute threshold was defined as the smallest amount of stimulus energy necessary to produce a sensation:
Since an organism’s sensitivity to external stimuli tends to fluctuate somewhere from moment to moment, several measurements of the threshold value of the stimulus are averaged to arrive to an accurate estimation of absolute threshold.
Perceptual representation of a stimulus is not constant; it involves an additive random error. It follows that the psychometric function is not a step-function. Instead it is a -shaped curve.
The A.T. is defined as the 50% percentile point:
- Absolute Sensitivity
- Measurement of absolute threshold has led to many significant advances in understanding sensory system.
- For example it has facilitated our understanding of vision, audition, touch.
- Sensory receptors in the hands:
