OPTIMIZING LINKED PERCEPTUAL CLASS FORMATION AND TRANSFER OF FUNCTION

A linked perceptual class consists of two distinct perceptual classes, A′ and B′, the members of which have become related to each other. For example, a linked perceptual class might be composed of many pictures of a woman (one perceptual class) and the sounds of that woman's voice (the other perceptual class). In this case, any sound of the woman's voice would occasion the selection of any picture of the woman and vice versa. In addition, after learning to name the woman in the presence of one picture, that name would be uttered when presented with all of the images of the woman's face and all of the sounds of her voice. This study involved 15 participants and sought to (a) maximize the percentage of participants who formed linked perceptual classes, and (b) determine whether those classes acted as transfer networks, that is, whether the discriminative function of one class member would generalize to other members of the class and not to members of a different class. The rate of emergence of each linked perceptual class was maximized by establishing a single class‐linking conditional relation between the clearest member of one class used as a sample stimulus and the most ambiguous member of the other class used as a comparison stimulus. Class formation was demonstrated using the serial and programmed presentation of A′–B′ probes that consisted of untrained pairs of stimuli drawn from the A′ and B′ classes. Most participants showed immediate emergence of the two linked perceptual classes. The remaining participants showed delayed emergence following a second exposure to each originally error‐producing probes. Once the linked perceptual classes had emerged, a differential response to a specific member of one perceptual class generalized mostly or completely to the other members of that linked class and rarely, if ever, to members of the other linked class. Thus, generalization did not depend on the specific class members that had been used for discrimination training.     

TRANSFER OF AVERSIVE RESPONDENT ELICITATION IN ACCORDANCE WITH EQUIVALENCE RELATIONS

The present study investigates the transfer of aversively conditioned respondent elicitation through equivalence classes, using skin conductance as the measure of conditioning. The first experiment is an attempt to replicate Experiment 1 in Dougher, Augustson, Markham, Greenway, and Wulfert (1994), with different temporal parameters in the aversive conditioning procedure employed. Match‐to‐sample procedures were used to teach 17 participants two 4‐member equivalence classes. Then, one member of one class was paired with electric shock and one member of the other class was presented without shock. The remaining stimuli from each class were presented in transfer tests. Unlike the findings in the original study, transfer of conditioning was not achieved. In Experiment 2, similar procedures were used with 30 participants, although several modifications were introduced (formation of five‐member classes, direct conditioning with several elements of each class, random sequences of stimulus presentation in transfer tests, reversal in aversive conditioning contingencies). More than 80% of participants who had shown differential conditioning also showed the transfer of function effect. Moreover, this effect was replicated within subjects for 3 participants. This is the first demonstration of the transfer of aversive respondent elicitation through stimulus equivalence classes with the presentation of transfer test trials in random order. The latter prevents the possibility that transfer effects are an artefact of transfer test presentation order.     

EMERGENT CONDITIONAL RELATIONS IN A GO/NO‐GO PROCEDURE: FIGURE—GROUND AND STIMULUS‐POSITION COMPOUND RELATIONS

Past research has demonstrated emergent conditional relations using a go/no‐go procedure with pairs of figures displayed side‐by‐side on a computer screen. The present study sought to extend applications of this procedure. In Experiment 1, we evaluated whether emergent conditional relations could be demonstrated when two‐component stimuli were displayed in figure—ground relationships—abstract figures displayed on backgrounds of different colors. Five normally capable adults participated. During training, each two‐component stimulus was presented successively. Responses emitted in the presence of some stimulus pairs (A1B1, A2B2, A3B3, B1C1, B2C2 and B3C3) were reinforced, whereas responses emitted in the presence of other pairs (A1B2, A1B3, A2B1, A2B3, A3B1, A3B2, B1C2, B1C3, B2C1, B2C3, B3C1 and B3C2) were not. During tests, new configurations (AC and CA) were presented, thus emulating structurally the matching‐to‐sample tests employed in typical equivalence studies. All participants showed emergent relations consistent with stimulus equivalence during testing. In Experiment 2, we systematically replicated the procedures with stimulus compounds consisting of four figures (A1, A2, C1 and C2) and two locations (left — B1 and right — B2). All 6 normally capable adults exhibited emergent stimulus—stimulus relations. Together, these experiments show that the go/no‐go procedure is a potentially useful alternative for studying emergent conditional relations when matching‐to‐sample is procedurally cumbersome or impossible to use.     

ALTERING THE NEAR‐MISS EFFECT IN SLOT MACHINE GAMBLERS

This study investigated the potential for recreational gamblers to respond as if certain types of losing slot machine outcomes were actually closer to a win than others (termed the near‐miss effect). Exposure to conditional discrimination training and testing disrupted this effect for 10 of the 16 participants. These 10 participants demonstrated high percentages of conditional discrimination testing performance, and the remaining 6 participants failed the discrimination tests. The implications for a verbally based behavioral explanation of gambling are presented.     

Transfer of baseline reject control to transitivity trials and its effect on equivalence class formation

This study explored the role of baseline reject control on transitivity responding. In Experiment 1, participants learned to respond to a baseline of arbitrary AB and AC conditional relations, and then they were exposed to transitivity‐like BC and CB trials in which the correct comparison stimulus was replaced by a novel stimulus (D). Five of 10 participants selected stimulus D, but only 1 showed expansion of the baseline stimulus classes to include the D stimuli. In Experiment 2, the emergence of symmetry and transitivity from baseline relations was assessed before participants were exposed to the transitivity‐like trials. Six of 8 participants who showed emergence of equivalence relations selected the D stimuli on transitivity‐like trials and provided evidence that baseline classes expanded to include these stimuli. In Experiment 3, these 6 participants selected novel stimuli (E) in additional transitivity‐like trials, and all showed that the E stimuli had become members of the previously established classes, which now comprised 5 members. A route for the emergence of transitivity by way of the transfer of baseline between‐classes reject control is discussed.     

Establishing derived categorical responding in children with disabilities using the PEAK‐E curriculum

The purpose of the study was to evaluate a procedure to generate derived categorical responding by three children with disabilities and to promote the emergence of untrained intraverbal categorical responses. In the study, three 4‐member equivalence classes including three stimuli (A, B, and C) and a category name (D) for each class were trained using a match‐to‐sample procedure. Test probes were conducted for categorical responding, including both a trained (D‐A) and two derived (D‐B, D‐C) relational responses, as well as the emergence of untrained intraverbal categorical responding (D‐A/B/C) throughout the study. Relational training was effective at promoting the emergence of categorical responding, and two of the three participants demonstrated the emergence of additional intraverbal responding without prior training. The results provide further evidence supporting the practical utility of stimulus equivalence as well as the PEAK‐E curriculum.     

Training intraverbal bidirectional naming to establish generalized equivalence class performances

The purpose of this study was to evaluate the effects of tact and intraverbal training on the establishment of generalized equivalence classes. Seventeen college students were exposed to tact training, listener testing, and intraverbal training (A'B’ and B'C’) in two experiments. Visual–visual matching‐to‐sample and intraverbal tests measured performances consistent with the formation of equivalence classes. Generalization was assessed with four novel sets of stimuli. In the second experiment, matching‐to‐sample tests for baseline relations (AB, BC) were eliminated to control for the possibility that equivalence classes were developed through exposure to these visual stimulus–stimulus relations. Thirteen of 17 participants passed all matching‐to‐sample and intraverbal posttests. Results suggest that when trained and emergent intraverbal relations were not maintained or were faulty, participants did not respond correctly during matching‐to‐sample posttests.     

Imitative learning from a third-party interaction: relations with self-recognition and perspective taking

Young children’s ability to learn something new from a third-party interaction may be related to the ability to imagine themselves in the third-party interaction. This imaginative ability presupposes an understanding of self-other equivalence, which is manifested in an objective understanding of the self and an understanding of others’ subjective perspectives. The current study measured imitative learning of a novel action seen only in a third-party interaction, mirror self-recognition, and perspective taking in a group of 48 18- to 20-month-olds. Patterns of performance suggest that understanding self-other equivalence is related to third-party learning.     

Effects of within-class differences in sample responding on acquired sample equivalence

Two experiments examined whether acquired sample equivalence in many-toone matching was affected by variation in sample-response requirements. In each experiment, pigeons responded on either identical or different response schedules to the sample stimuli that occasioned the same reinforced comparison choice (i.e., to the within-class samples). Transfer-of-control tests were then conducted to determine acquired equivalence, or lack thereof, between these samples. In both experiments, there was minimal or no evidence of acquired sample equivalence when pigeons responded differently to the samples within each common-choice class. By contrast, transfer was observed if pigeons responded (a) identically to all sample stimuli, or (b) identically to samples within each common-choice class (viz., to samples that occasioned the same reinforced choice) and differently to samples from different classes (viz., to samples that occasioned different choices). These results may help to explain the recent lack of evidence for response membership in pigeons' acquired equivalence (Urcuioli, Lionello-DeNolf, Michalek, & Vasconcelos, 2006). They also raise questions about the functional sample stimuli and about possible interactions between acquired equivalence and acquired distinctiveness.     

Relational learning in children with deafness and cochlear implants

This four-experiment series sought to evaluate the potential of children with neurosensory deafness and cochlear implants to exhibit auditory-visual and visual-visual stimulus equivalence relations within a matching-to-sample format. Twelve children who became deaf prior to acquiring language (prelingual) and four who became deaf afterwards (postlingual) were studied. All children learned auditory-visual conditional discriminations and nearly all showed emergent equivalence relations. Naming tests, conducted with a subset of the children, showed no consistent relationship to the equivalence-test outcomes. This study makes several contributions to the literature on stimulus equivalence. First, it demonstrates that both pre- and postlingually deaf children can acquire auditory-visual equivalence relations after cochlear implantation, thus demonstrating symbolic functioning. Second, it directs attention to a population that may be especially interesting for researchers seeking to analyze the relationship between speaker and listener repertoires. Third, it demonstrates the feasibility of conducting experimental studies of stimulus control processes within the limitations of a hospital, which these children must visit routinely for the maintenance of their cochlear implants.