Benigno Alonso-Álvarez

Emergence of Complex Conditional Discriminations by Joint Control of Compound Samples.

The goal of the present study was to explore the emergence of verbal behavior resulting from the joint control of two antecedent stimuli that are presented together for the first time. Conditional discriminations were used for teaching and for probing. Four stimuli P1, P2, Q1, and Q2 were samples and four stimuli A1, A2, B1, and B2 were the comparisons in all discriminations of the study. We taught 4 conditional discriminations with 1 sample and 2 comparisons in each trial; overall, each sample controlled selections of 2 comparison stimuli (i.e., sample P1 controlled selections of A1 in 1 conditional discrimination and controlled selections of B1 in another conditional discrimination). In a probe with no reinforcement, 1 P and 1 Q stimuli formed a compound sample, and the 4 comparisons appeared in each trial. Only selections of 1 comparison have been reinforced in the presence of the 2 sample stimuli during teaching (i.e., only selections of A1 have been reinforced in the presence of P1, in 1 conditional discrimination, and in the presence of Q1, in the other conditional discrimination). We analyzed whether the 2 sample stimuli would jointly control comparison selections. In Study 1, 2 adult participants did not show the emergence of the discrimination with the compound samples. In Study 2, we modified the procedure of Study 1 in such a way that (a) a prompt procedure was used, (b) trials of the 4 single-sample conditional discriminations were gradually intermixed, and (c) the reinforcement was reduced. The 2 adult participants showed the emergence of the conditional discrimination with the compound samples. This study thus demonstrated the emergence of discriminations by joint control. These results have important consequences for the study of language.

The selective impact of Skinner’s Verbal Behavior on empirical research: A reply to Schlinger (2008)

In a recent article, Schlinger (2008) marked the 50th anniversary of the publication of Skinner’s Verbal Behavior (1957) by considering its impact on the field of behaviorism and research on verbal behavior. In the present article, we comment on Schlinger’s conclusions regarding the impact of the book and highlight the extensions and alternatives to Skinner’s account proposed by research on stimulus equivalence and derived relational responding. Moreover, we argue that Verbal Behavior has had a selective impact on empirical research and that only further basic and applied research will determine whether the next 50 years of behavior-analytic research on verbal behavior will live up to the promise that Skinner envisaged.

Hierarchy Among Intersecting Equivalence Classes Formed by Unitary and Compound Stimuli

In Part 1 of the present research, three college students were trained in four interrelated conditional discriminations in which unitary stimuli were presented as samples and as comparisons. Subsequently, participants were presented with symmetry and equivalence tests that evaluated the formation of four intersecting equivalence classes, with each class made up of three unitary stimuli (e.g., A1-P1-B1, A1-Q1-A2, etc.). Two out of three participants passed the tests (the third one also did so in a follow-up probe). In Part 2, the trained discriminations were reviewed and the three participants demonstrated the emergence of four conditional discriminations, in which unitary samples and compound comparisons were presented, or vice versa. These discriminations defined symmetric relations among pairs of unitary and compound stimuli (e.g., A1 and P1Q1); therefore, we concluded that the stimuli of each pair were members of an equivalence class. In Part 3, the same participants were presented with two conditional discriminations probes in which they related same-class unitary and compound stimuli (e.g., A1 and P1Q1), instead of relating same-class unitary stimuli (e.g., A1 and P1, or A1 and Q1). Therefore, we concluded that there is a hierarchy among these intersecting equivalence classes and that the classes formed by unitary and compound stimuli have precedence over the classes formed only by unitary stimuli.

Contextual control over equivalence and nonequivalence explains apparent arbitrary applicable relational responding in accordance with sameness and opposition

We evaluated whether contextual control over equivalence and nonequivalence (i.e., selecting comparisons equivalent to the samples in the presence of a contextual cue, and excluding the selection of comparisons equivalent to the samples in the presence of another contextual cue) can account for apparent arbitrarily applicable relational responding (AARR) in accordance with the frames of sameness and opposition, as defined in relational frame theory (RFT). Three college students were trained to maintain previously established conditional discriminations in the presence of a contextual cue X1, and to reverse them in the presence of another contextual cue X2 (e.g., X1–A1B1, X1–A2B2, X2–A1B2, X2–A2B1). Subsequent tests demonstrated that X1 and X2 functioned as cues for equivalence and nonequivalence. Later on, X1 and X2 were demonstrated to be functionally equivalent to supposed contextual cues for the frames of sameness and opposition employed in RFT studies (i.e., SAME and OPPOSITE cues), in tests for arbitrary and nonarbitrary derived stimulus relations. The functional equivalence of X2 and OPPOSITE suggests that OPPOSITE worked as a cue for nonequivalence. Thus, the results in RFT studies with SAME and OPPOSITE can be explained just by contextual control over equivalence and nonequivalence. Therefore, the explanation that they actually demonstrated AARR in accordance with the frames of sameness and opposition can be questioned and replaced by a more parsimonious explanation, based on a few simple learning principles. We discuss the implications of this conclusion for the debate among competing theories about the origin of stimulus equivalence and other derived stimulus–stimulus relations.

Analysis of apparent demonstrations of responding in accordance with relational frames of sameness and opposition: APPARENT RELATIONS OF SAMENESS AND OPPOSITION

We evaluated whether contextual control over equivalence and nonequivalence and responding by exclusion can explain the outcomes of relational frame theory (RFT) studies on sameness and opposition relations. We trained nine college students to maintain and reverse conditional discriminations with X1 and X2 as contextual stimuli. In Experiment 1, X1 and X2 controlled derived stimulus relations (DSR) analogous to those controlled by Same and Opposite in RFT studies. These results can be explained by at least two hypotheses: X1 and X2 were cues for equivalence and nonequivalence and responding by exclusion, or for sameness and opposition. In Experiment 2, X1 and X2 controlled DSR predicted by the hypothesis that they were cues for equivalence and nonequivalence and responding by exclusion, and not predicted by the hypothesis that they were cues for sameness and opposition. The results of Experiment 2 and the functional equivalence of X1 and X2 with Same and Opposite in Experiment 1 suggest that Same and Opposite were cues for equivalence and nonequivalence and responding by exclusion in RFT studies.

Spontaneously hypertensive (SHR) rats choose more impulsively than Wistar-Kyoto (WKY) rats on a delay discounting task

HighlightsConcurrent‐chains procedures detect differences in impulsive choice between SHRs and WKYs.The SHR is a suitable model for ADHD.The hyperbolic‐decay model and the generalized matching law fit delay discounting data.Positive correlations between k and s suggest compatibility between these models.Impulsivity increases with training. &NA; Indications of Attention Deficit Hyperactivity Disorder (ADHD) in the spontaneously hypertensive rat (SHR) are not consistent across different tests of impulsivity, questioning the SHRs validity as a rodent model of ADHD. This study used a concurrent‐chains procedure to examine possible differences in impulsive choice between SHRs and control‐normotensive Wistar Kyoto (WKY) rats. The aim was to extend the generality of findings showing regularities between the hyperbolic‐decay model and the generalized matching law fitting delay discounting data from nonhuman animals. The objectives were to: (1) examine differences in impulsive choice between SHRs and WKYs; (2) add evidence suggesting that the SHR is a suitable model of ADHD; (3) demonstrate that concurrent‐chains procedures requiring locomotion detect differences in impulsive choice between SHRs and WKYs; (4) support the idea that impulsivity in nonhuman animals increases with training. The initial link used two non‐independent random interval schedules arranging entries to the terminal links, where one fixed‐time (FT) schedule delayed 1‐food pellet and the other FT 4‐food pellets. The FT delaying the former was kept constant at 0.1 s and that delaying the latter changed after every 10 food deliveries, defining six delay components (0.1, 5, 10, 20, 40, and 80 s) presented in random order each session. Results showed that the SHRs choose more impulsively than the WKYs, adding to the body of evidence suggesting that the SHR may be a suitable model of ADHD. Both models of choice fitted the impulsive choices of the SHRs and WKYs well; positive correlations between estimates of parameters k and s suggested compatibility between models of choice showing that impulsivity increases with training.

Teaching a Simple Discrimination Using a Blocked-Trial Procedure to Overcome Location Overselectivity

This investigation explored whether a blocked-trial procedure would serve to teach a simple discrimination to a child with autism with problems of overselectivity due to location preference. A series of AB designs were used. The child learned first to select positive stimulus (a card with his name) regardless of its location on a screen. Thereafter, the positive stimulus was located in the lower left position and a negative stimulus was located in the lower right position on the screen. Once he learned to select the correct stimulus, the locations were reversed. Upon further mastery, the number of trials with the stimuli in a given location was progressively decreased, until he learned the discrimination with the stimuli at random locations. Further probes indicated that the letters controlled responding, rather than irrelevant features. Finally, the selection of the card with his name continued when the stimuli were located in any of four locations on the screen, and when three cards with names of other children appeared as distractors. Thus, the procedure may serve to teach discriminations and to overcome overselectivity in children with autism and other developmental disabilities.