Six pigeons responded in a visual category learning task in which the stimuli were dimensionally separable Gabor patches that varied in frequency and orientation. We compared performance in two conditions which varied in terms of whether accurate performance required that responding be controlled jointly by frequency and orientation, or…

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract…

We investigated changes in bias (preference for one response alternative) in signal detection when relative reinforcer frequency for correct responses varied across sessions. In Experiment 1, 4 rats responded in a two-stimulus, two-response identification procedure employing temporal stimuli (short vs. long houselight presentations). Relative…

Sidman (1994) noted that the existence of a member that is common to more than one class may produce either class merger (union) or class intersection. A multiple-selection, matching-to-sample test was developed to examine the conditions under which these outcomes occur. Test trials each required three conditional discriminations involving…

Three experiments used postclass formation within-class preference test performances to evaluate the effects of nodal distance on the relatedness of stimuli in equivalence classes. In Experiment 1, two 2-node four-member equivalence classes were established using the simultaneous protocol in which all of the baseline relations were trained…

The purpose of this study was to assess the role of common motor responses as the "speaker" behavior on stimulus class formation,and the emergence of functional classes. Experiment 1 examined whether training one motor response to a set of three stimuli and a second motor response to another set of three stimuli would result in correct…

Three experiments investigated responding consistent with transitive class containment, a feature of hierarchical classification. Experiment 1 replicated key components of a preliminary attempt to model hierarchical classification (Griffee & Dougher, 2002) and tested for responding consistent with transitive class containment. Only 2 out of 5…

Excessively devaluing delayed reinforcers co-occurs with a wide variety of clinical conditions such as drug dependence, obesity, and excessive gambling. If excessive delay discounting is a trans-disease process that underlies the choice behavior leading to these and other negative health conditions, efforts to change an individual's discount rate…

By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of…

Acquired equivalence is a paradigm in which generalization is increased between two superficially dissimilar stimuli (or antecedents) that have previously been associated with similar outcomes (or consequents). Several possible mechanisms have been proposed, including changes in stimulus representations, either in the form of added associations or…

Most complex categories observed in real-world settings consist of perceptually disparate stimuli, such as a picture of a person's face, the person's name as written, and the same name as heard, as well as dimensional variants of some or all of these stimuli. The stimuli function as members of a single partially or fully elaborated generalized…

When the stimuli in one perceptual class (A') become related to the stimuli in another perceptual class (B'), the two are functioning as a single "linked perceptual class". A common linked perceptual class would be the sounds of a person's voice (class A') and the pictures of that person (class B'). Such classes are ubiquitous in real…

The purpose of the current study was to assess whether children would categorize pictures when taught the relevant listener and speaker behaviors separately. A category-sort test was used to assess emergent conditional relations. Category-sort trials consisted of looking at (Test 1) or tacting/labeling (Test 2) a sample stimulus and selecting the…

This paper reports two experiments that investigated the role of verbal behavior in the emergence and generalization of contextually controlled equivalence classes. During both experiments, participants were trained with two different combinations of the same easily nameable, yet formally unrelated, pictorial stimuli. Match-to-sample baselines for…

Following pre-training with everyday objects, 8 children aged from 2 to 4 years learned to produce one manual sign (fists placed one above the other, in front of body) to one stimulus and an alternative manual sign (shoulders touched with ipsilateral hands) to the other stimulus, with each of three pairs of different arbitrary wooden shapes (Set…