Establishing equivalence classes in younger and older adults : evaluating the effect of a differential outcome procedure

Abstract

Studies have shown that older adults may not establish baseline conditional discrimination as readily as younger adults. Sidman suggested that all elements of the four-term contingency enter the equivalence class, and studies have shown that class specific consequences may increase the likelihood of establishing the baseline conditional discriminations. The purpose of the study is to 1) compare the acquisition of baseline conditional discriminations in younger and older adults using arbitrarily related abstract stimuli, 2) study the effect of the DOP on the establishment of baseline conditional discriminations, and 3) compare equivalence class formation in younger and older adults. Twenty-four participants were recruited for study, 12 younger adults (20-30 years old) and 12 older adults (67+ years old). If a participant responded with 50% or less correct after repeated exposure to three baseline conditional discriminations (180 training trials), the participant was exposed to a differential outcome procedure (DOP) for evaluation of whether such a procedure may facilitate the establishment of the baseline conditional discrimination. Total of five participants in the older adults group received the additional DOP training trials. The results show that only two out of the five participants that recived DOP training trials established the AB baseline conditional discrimination. Furthermore, The results of the post-test show that 0% of the older adults with DOP responded in accordance with equivalence, about 29% of the older adults’ group, and only 50% of the younger group. From these results, it can be concluded that exposure to the class specific consequences had minimal effect on the establishment of the baseline conditional discrimination.Key-words: conditional discrimination, younger adults, older adults, differential outcome procedure, stimulus equivalence