Conditional Discrimination and Equivalence Relations: Control by Negative Stimuli

Abstract

Three adult subjects were taught the following two-sample, two-comparison conditional discriminations (each sample is shown with its positive and negative comparison, in that order): A1-B1B2, A2-B2B1; B1-C1C2, B2-C2C1; and C1-D1D2, C2-D2D1. A teaching procedure was designed to encourage control by negative comparisons. Subjects were then tested for emergent performances that would indicate whether the baseline conditional discriminations were reflexive, symmetric, and transitive. The tests documented the emergence of two classes of equivalent stimuli: A1, B2, C1, D2 and A2, B1, C2, D1. These were the classes to be expected if the negative comparisons were the controlling comparisons in the baseline conditional discriminations. The negative comparisons, however, were not the comparisons that subjects were recorded as having chosen in the baseline conditional discriminations. Differential test results confirmed predictions arising from a stimulus-control analysis: In reflexivity tests (AA, BB, CC, DD), subjects chose comparisons that differed from the sample; one-node transitivity (AC, BD) and "equivalence" (CA, DB) tests also yielded results that were the opposite of those to be expected from control by positive comparisons; symmetry tests (BA, CB, DC), two-node transitivity (AD) tests, and two-node "equivalence" (DA) tests yielded results that were to be expected from control by either positive or negative comparisons.

Topography of Responses in Conditional Discrimination Influences Formation of Equivalence Classes

“…Since, in the present study, participants who showed complete sample-S+ control also tended to show complete sample-S-control, it is difficult to determine whether sample-S-control was necessary or not for class formation. this could be done with a method that induced particular controlling relations (e.g., Johnson & Sidman, 1993), so that equivalence outcomes could be compared for participants who learned only sample-S+ relations and participants who learned both sample-S+ and sample-S-relations.…”

Equivalence Class Establishment with Two-, Three-, and Four-Choice Matching to Sample by Senior Citizens

“…Until recently, nearly all equivalence research showing such differences was conducted with two-choice MTS methods (Fields, Hobbie-Reeve, Adams, & Reeve, 1999; K. J. Saunders et aI., 1993; R. R. Saunders, Drake, & Spradlin, 1999; R. R. Saunders et aI., 1988;Spradlin & Saunders, 1986). Several researchers have noted that with two-choice MTS procedures, responding during training and testing might induce sample/S-control rather than sample/S+ control (Carrigan & Sidman, 1992;Johnson & Sidman, 1993;Sidman, 1994). Sample/S-control refers to the inference that "correct" responding is a function of "rejecting" the incorrect choice stimulus in the trial as opposed to "selecting" the correct choice (Carrigan & Sidman, 1992).…”

Increasing the Generativity of Identity-Based Procedures for Establishing Arbitrary Conditional Relations

“…The training and testing format used prior to the set-merger tests of Phase 4.3 always employed configurations of two comparison stimuli from the S-class with one from the S+ class (e.g., if the correct comparison was a stimulus from Set 1, the incorrect comparisons were both from Set 2). Under such conditions, subjects can form an exclusion-based response strategy that focuses on the relationship between the sample and the incorrect comparison(s) rather than the relationship between the sample and correct comparison (Carrigan & Sidman, 1992;Johnson & Sidman, 1993). In the current study, such a response strategy could have produced accurate performances during training and during the equivalence tests of Phases 2.5 and 3.5.…”