Stability of Functional Equivalence and Stimulus Equivalence: Effects of Baseline Reversals

Abstract

Functional equivalence and stimulus equivalence classes were established, reversed, and tested for stability with college students. Functional stimulus classes were established using a task in which students were trained to say nonsense words in the presence of arbitrarily assigned sets of symbols. Computer-controlled speech-recognition technology was used to record and analyze students' vocal responses for accuracy. After the establishment of stimulus classes was demonstrated with a transfer-of-function test, the effects of reversing selected baseline simple discriminations were assessed during an additional transfer-of-function test and a follow-up test that occurred several weeks later. With the same students, stimulus equivalence classes were established and demonstrated with computerized matching-to-sample procedures. The effects of reversing selected baseline conditional discriminations also were assessed during a postreversal equivalence test and a follow-up test. Both functional stimulus classes and stimulus equivalence were sensitive to contingency reversals, but the reversals with stimulus equivalence closses affected stimulus class organization whereas reversals with functional stimulus classes did not. Follow-up performances were largely consistent with the original baseline contingencies. The similarities and differences between stimulus equivalence and functional equivalence are related to the specific contingencies that select responding in the presence of the stimuli that form the classes.

A Derived Relations Analysis of Approach-Avoidance Conflict: Implications for the Behavioral Analysis of Human Anxiety

“…Consideration of this issue may also provide some insights into performances during probe phases. Specifically, the current experimental preparations bear some functional similarity to preparations used to examine the effect of established functional classes on the emergence or reorganization of stimulus equivalence classes, and vice versa (e.g., Roche, Barnes, & Smeets, 1997;Tyndall, Roche, & James, 2004, Wirth & Chase, 2002. Such studies have generally found that incongruous relations between functional and stimulus equivalence classes lead to the delayed emergence or disruption of one or the other.…”

“…Indeed, there is research evidence for this precise outcome. Specifically, Wirth and Chase (2002) found that the reversal of selected baseline simple discriminations used to disrupt two functional equivalence classes resulted in the complete reversal of response functions across both classes. They argued that this is to be expected because once functional equivalence among stimuli is established, any change in responding applied to one stimulus of a set must, by definition, be applied similarly to the other stimuli in the class.…”

The interfering effect of emotional stimulus functions on stimulus equivalence class formation: implications for the understanding and treatment of anxiety

“…Thus, it may be important to understand how to target or 'break-up' these maladaptive classes. Indeed, a number of researchers have examined whether or not established functional or stimulus equivalence classes can easily be reorganised (e.g., Dixon, Rehfeldt, Zlomke, & Robinson, 2006;Pilgrim, Chambers, & Galizio, 1995;Pilgrim & Galizio, 1990Smeets, Barnes-Holmes, Akpinar, & BarnesHolmes, 2003;Smeets, Barnes-Holmes, & Striefel, 2006;Wirth & Chase, 2002). Wilson and Hayes (1996) noted that two types of reversal training procedures have generally been employed in the empirical literature, complete reversal and partial reversal.…”

“…Partial reversal is more commonly used which involves reversing only some of the trained relations and is usually less successful in reversing the established equivalence relations. While some suggestions have been made (e.g., as to the conditions under which established equivalence relations can be reorganised the general finding is that equivalence relations, once formed are difficult to change (e.g., Follette, 1998;Rehfeldt & Hayes, 2000;Wirth & Chase, 2002), with symmetry relations generally more sensitive to contingency reversals than symmetric transitivity (equivalence) relations (Smeets, et al, 2003).…”

“…The present study was designed to improve and extend upon the Tyndall et al (2004) study and to help elucidate the complex relationship between functional equivalence and stimulus equivalence (see Dymond & Rehfeldt, 2000;Fields, 2001;Hall, 2001;Markham & Markham, 2002;Minster, Jones, Eliffe, & Muthukamarasawmy, 2006;Tonneau, 2001;Tonneau & Gonzalez, 2004, Wirth & Chase, 2002. In this study, six nonsense syllables were directly paired with six aversive images and a further six nonsense syllables were paired directly with six neutral images to establish two respondent function stimulus classes, an Aversive Stimulus class and a Neutral Stimulus class.…”