Reversal of Baseline Relations and Stimulus Equivalence: Ii. Children

Abstract

In a systematic replication of a study using college-student subjects (Pilgrim & Galizio, 1990), 5-to 7-year-old children learned two conditional discriminations (i.e., AlBI, A2B2, AICI, and A2C2) in a two-choice arbitrary match-to-sample task and showed the emergence of two three-member equivalence classes (AlBICI and A2B2C2). Baseline conditional discrimination performances were quickly controlled by reversals of the AC reinforcement contingencies (i.e., choosing Comparison Stimulus C2 was reinforced given Sample Al, and choosing Cl was reinforced given Sample A2) when the reversals were introduced in restricted baselines. On reflexivity, symmetry, and transitivity/equivalence probes following the reversal, there was some limited indication of equivalence-class reorganization (i.e., AlBlC2 and A2B2C1) in keeping with the concurrently performed baseline relations for 2 of 5 subjects, but the predominant pattern across probe trials was one of inconsistent conditional control. These findings suggest that, given similar challenges, equivalence-class performances may be more easily disrupted in young children than in adults.Key words: stimulus equivalence, conditional discrimination, discrimination reversal, object displace-Despite the recent explosion of empirical studies targeting the phenomenon of stimulus equivalence, only limited information is available regarding factors that may influence equivalence performances subsequent to their initial emergence. Such information is an important next step in understanding the functioning of "equivalence" and in furthering the analysis of its properties as an operant class. As one experimental strategy toward this end, identifying conditions that disrupt class performances may provide a clearer understanding of the variables controlling these discriminative patterns and their maintenance.In a recent study from this laboratory (Pilgrim & Galizio, 1990) classes (i.e., AlBlCl and A2B2C2), collegestudent subjects were exposed to a reversal of the AC baseline relations. In the reversal condition, choosing Comparison Stimulus C2 was reinforced given Sample Al; choosing Cl was reinforced given Sample A2. This manipulation might have been expected to produce a reorganization of the classes (i.e., A1B1C2 and A2B2C1). The surprising results were that although symmetry probe performances were immediately controlled by the reversal of baseline relations for 3 of 4 subjects (i.e., Al was chosen given a C2 sample, and A2 was chosen given a Cl sample), reflexivity and transitivity/equivalence performances remained consistent with the original equivalence classes. The generality of these basic findings has recently been extended in further analysis with 5 additional young adults, for whom symmetry but not transitivity/ equivalence performances were immediately controlled by baseline reversals (Pilgrim & Galizio, 1995).The inconsistencies between transitivity/ equivalence and baseline performances are interesting because baseline relations are commonly held to be the basis for equivalenc...

Reorganization of Equivalence Classes After Reversal of Baseline Relations

“…These results are not consistent with previous studies that have not found reorganization of equivalence classes after baseline reversals (Pilgrim, Chambers, & Galizio, 1995;Pilgrim & Galizio, 1990Saunders, Saunders, Kirby, & Spradlin, 1988). Perhaps the most puzzling result was obtained by Galizio (1990, 1995).…”

The Long-Term Retention Of Generalized Equivalence Classes

“…This finding supports the notion that the stimuli constituting an equivalence class are not necessarily equally substitutable for one another (Adams et aI., 1993;Saunders & Green, 1992). It also supports the view that the relations defining equivalence class membership may be construed as differential operant units (Pilgrim, Chambers, & Galizio, 1995;Pilgrim & Galizio, 1990. Those subjects who demonstrated the maintenance of one or both equivalence relations or the two withincompound, relations also demonstrated the maintenance of at least two symmetry relations.…”

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.…”