Domestic hens responded under multiple fixed-ratio fixed-ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasi-randomly so that all four possible transitions occurred in each session.…

Virtual organisms animated by a selectionist theory of behavior dynamics worked on concurrent random interval schedules where both the rate and magnitude of reinforcement were varied. The selectionist theory consists of a set of simple rules of selection, recombination, and mutation that act on a population of potential behaviors by means of a…

Two experiments used post-class formation within-class relational assessment test performances to evaluate whether participants demonstrated preference for certain members of an equivalence class based on the type of relation that existed between class members. In Experiment 1, two 5-node 7-member equivalence classes, consisting entirely of…

Although response-dependent shock often suppresses responding, response facilitation can occur. In two experiments, we examined the suppressive and facilitative effects of shock by manipulating shock intensity and the interresponse times that produced shock. Rats' lever presses were reinforced on a variable-interval 40-s schedule of food…

Pigeons trained on successive AB symbolic matching show emergent BA antisymmetry if they are also trained on successive AA oddity and BB identity (Urcuioli, 2008, Experiment 4). In other words, when tested on BA probe trials following training, they respond more to the comparisons on the reverse of the nonreinforced AB baseline trials than on the…

In Experiment 1, food-deprived rats responded to one of two schedules that were, with equal probability, associated with a sample lever. One schedule was always variable ratio, while the other schedule, depending on the trial within a session, was: (a) a variable-interval schedule; (b) a tandem variable-interval,…

Signals during delays to reinforcement may lessen reductions in responding that typically occur when there is a delay between a response and its reinforcer. Sparse applied research has been devoted to understanding the conditions under which responding may be maintained when delays to reinforcement are introduced. We evaluated the extent to which…

Transitivity of preferences has been investigated for a long time in decision-making. In the field of perception, the pleasantness of odors raises several questions related to individual versus cultural or universal preferences and the existence of a classification in a delimited hedonic space. The aim of this study was to test transitivity in…

When given to pigeons, the direct-acting dopamine agonist apomorphine elicits pecking. The response has been likened to foraging pecking because it bears remarkable similarity to foraging behavior, and it is enhanced by food deprivation. On the other hand, other data suggest the response is not related to foraging behavior and may even interfere…

The relationship between positive and negative reinforcement and the symmetry of Thorndike's law of effect are unresolved issues in operant psychology. Here we show that, for a given pattern of responding on variable interval (VI) schedules with the same programmed rate of food rewards (positive reinforcement VI) or electric shocks (negative…

In comparing open and closed economies, researchers often arrange shorter sessions under the former condition than under the latter. Several studies indicate that session length per se can affect performance and there are some data that indicate that this variable can influence demand functions. To provide further data, the present study exposed…

The effects of a history of differential reinforcement for selecting a free-choice versus a restricted-choice stimulus arrangement on the subsequent responding of 7 undergraduates in a computer-based game of chance were examined using a concurrent-chains arrangement and a multiple-baseline-across-participants design. In the free-choice…

Resurgence is the reappearance of an extinguished behavior when an alternative behavior reinforced during extinction is subsequently placed on extinction. Resurgence is of particular interest because it may be a source of relapse to problem behavior following treatments involving alternative reinforcement. In this article we develop a quantitative…

Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more…

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…