Comparison of three methods for obtaining psychophysical thresholds from the pigeon.

Abstract

Three methods for obtaining differential thresholds for brightness from pigeons were compared. The 3 conditions were the 2-and 4-key forced-choice methods and the "yes-no" method. Each method yielded consistent psychophysical functions that approximated the classic ogival form. None of the methods proved consistently superior. Individual differences were large. The data were analyzed for habit tendencies that might interfere with stimulus control of behavior. One such tendency was the formation of strong position habits which varied in strength as a function of the difficulty of the discrimination.