A Simpler Route to Stimulus Equivalence? A Replication and Further Exploration of a “Simple Discrimination Training Procedure” (Canovas, Debert and Pilgrim 2014)

Abstract

In a recent paper in this journal, Canovas, Debert and Pilgrim (The Psychological Record, 65(2), 337–346, 2015), in their second experiment, taught participants to make one key press to each of three simple visual stimuli and an alternative response to another three. They then trained two new key presses to one stimulus from each class, which then transferred to the other stimuli in each class. When subsequently presented with compounds of two stimuli, participants indicated “correct” to within-class compounds, but “incorrect” to between-class compounds. The present study starts with a successful replication of this seemingly new way of establishing stimulus equivalence classes, with an added matching-to-sample test at the end. In two further experiments, the visual stimuli were replaced by non-words, with two further non-words to be said aloud in place of key-presses. These showed that it was possible to establish two or three equivalence classes using such initial discrimination training, even when the prior demonstration of functional equivalence classes by transfer-of-training to a second set of responses was omitted. Other ways of conceptualizing these methods of training are considered, together with some implications for enlarging our understanding of equivalence class formation.