“Shaping” of Frequency Discrimination Performance Using Only Intrinsic Reinforcement

Abstract

This experiment compared two modes of practice at a difficult frequency discrimination, i.e., one in which the frequency difference was initially correctly discriminated only 65% of the trials in a two-alternative forced-choice task. One group of Ss ( N = 13) was assigned to a progressive-practice group, in which the frequency difference to be discriminated was progressively changed from a large, easy, difference to the difficult, small, difference. The other group of Ss ( N = 13) received the same amount of practice as the first, but all at the difficult discrimination. Only the progressive-practice group improved their discrimination performance. Since no feedback was given, the effect of progressive practice is interpreted as “shaping” Ss' attentional response by virtue of the information provided by the successively more difficult discriminations. This “shaping” process is potentially available as a learning mechanism for other fine discriminations.