Differential perceptibility threshold
The differential (also differential ) perception threshold (also JND of English. Just Noticeable Difference "just been noticeable difference") referred to in the psychophysics one just yet sensible stimulus difference .
Forced choice attempts are often used to determine differential perceptibility thresholds. Here, a test person is presented with several situations with a defined difference. The test person has the task of arranging the situations according to certain criteria (e.g. which noise is louder, which light is brighter, etc.) In the course of the experiments, the differences between the situations become smaller and smaller. Above the discrimination threshold, the differences can be recognized and correctly classified. If the differential perceptibility threshold is reached, no difference can be recognized on the basis of one's own perceptions, the classification of the situations becomes purely random. The transition to random information can be recognized by statistical evaluation of the results. The differential perceptibility threshold is assigned to this transition point.
Interval judgments (“Hear / Do you see a difference?”) Are used less often to determine differential perceptibility thresholds, as they are less precise than forced choice experiments: In psychophysical experiments , the test person approaches the differential perceptibility threshold slowly, but if possible exposed to continuously changing distal stimuli , such as A log in as amplitude or frequency -changing tone to fine discrimination of perception by the human (rarely also animal ) sense organs to be measured. If the test person shows a clear reaction because they notice the difference in stimuli and can possibly also name the increase or decrease in the stimulus, the difference between the initial and final stimuli is the differential perceptibility threshold.
It turns out that the perceptibility of differences is very low when the limits of perceptibility are reached (very strong and very weak stimuli, lower and upper ranges of perception). Furthermore, there are considerable individual differences between the test subjects, e.g. B. Dependence of the measurement results on age and physical disposition. The differential perceptibility threshold can also be reduced through habituation or "training": Musicians show a finer perception of frequency differences, chefs and sommeliers a more precise distinction of taste .
- David Menke: Musical Aspects of Intonation: A Study of Artistic Use . 2009, ISBN 3-8366-8193-5 , pp. 16 ( Google Book Preview in Google Book Search).