Despite the intimate relationship dogs share with humans in Western society, we know relatively little about the variables that produce and maintain dog social behavior towards humans. One possibility is that human social interaction is itself a reinforcer for dog behavior. As an initial assessment of the variables that might maintain dog social…

This research investigated the source of an ostensible reflexivity effect in pigeons reported by Sweeney and Urcuioli (2010). In Experiment 1, pigeons learned two symmetrically reinforced symbolic successive matching tasks (hue-form and form-hue) using red-green and triangle-horizontal line stimuli. They differed in their third concurrently…

This experiment compared descriptions of concurrent choice by the stay/switch model, which says choice is a function of the reinforcers obtained for staying at and for switching from each alternative, and the generalized matching law, which says choice is a function of the total reinforcers obtained at each alternative. For the stay/switch model…

Zentall and Singer (2007a) hypothesized that our failure to replicate the work-ethic effect in pigeons (Vasconcelos, Urcuioli, & Lionello-DeNolf, 2007) was due to insufficient overtraining following acquisition of the high- and low-effort discriminations. We tested this hypothesis using the original work-ethic procedure (Experiment 1) and one…

The differential reinforcement of low rate (DRL) schedule is commonly used to assess impulsivity, hyperactivity, and the cognitive effects of pharmacological treatments on performance. A DRL schedule requires subjects to wait a certain minimum amount of time between successive responses to receive reinforcement. The DRL criterion value, which…

The current experiment examined whether adjusting-amount and adjusting-delay procedures provide equivalent measures of discounting. Pigeons' discounting on the two procedures was compared using a within-subject yoking technique in which the indifference point (number of pellets or time until reinforcement) obtained with one procedure determined…

Mice from replicate lines, selectively bred based on high daily wheel-running rates, run more total revolutions and at higher average speeds than do mice from nonselected control lines. Based on this difference it was assumed that selected mice would find the opportunity to run in a wheel a more efficacious consequence. To assess this assumption…