Combinations of Response‐dependent and Response‐independent Schedule‐correlated Stimulus Presentation in an Observing Procedure

Abstract

Pigeons pecked a response key on a variable-interval (VI) schedule, in which responses produced food every 40 s, on average. These VI periods, or components, alternated in irregular fashion with extinction components in which food was unavailable. Pecks on a second (observing) key briefly produced exteroceptive stimuli (houselight flashes) correlated with the component schedule currently in effect. Across conditions within a phase, the dependency between observing and presentation of the stimuli was decreased systematically while the density of stimulus presentation was held constant. Across phases, the proportion of session time spent in the VI component was adjusted from 0.5 to 0.25, and then to 0.75. Results indicate that rate of observing decreased as the dependency between responses and stimulus presentations was decreased. Further, discriminative control by the schedule-correlated stimuli was systematically weakened as dependency was decreased. Increasing the proportion of session time spent in VI decreased the rate of observing. This effect was additive with the manipulation of the dependency between observing and presentation of the stimuli. Overall, these results show that conditioned reinforcers function similarly to unconditioned reinforcers with respect to responseconsequence dependencies, and that stimulus control is enhanced under conditions in which the relevant stimuli are produced by an organism's behavior.

The generality of nicotine as a reinforcer enhancer in rats: effects on responding maintained by primary and conditioned reinforcers and resistance to extinction

“…Here, observing response rates were calculated by taking the total number of observing responses during the mixed schedule (i.e., no schedule-correlated stimuli) divided by the time spent in the mixed schedule (regardless of the component). This is a common method for calculating observing response rates (e.g., DeFulio and Hackenberg 2008;Shahan and Podelsnik 2008). Acute nicotine administration resulted in a significant difference across groups (F(2,81)=7.25), with the 0.3 Nicotine group showing significantly higher response rates than the Vehicle and 0.56 Nicotine groups.…”

Revisiting the Role of Bad News in Maintaining Human Observing Behavior

“…They argued that the case for the conditioned‐reinforcement hypothesis was unproven where humans were concerned. With a resurgence of interest in observing‐response experiments (e.g., DeFulio & Hackenberg, 2008; Fantino, 2008; Pessoa, Huziwara, Perez, Endemann, & Tomanari, 2009; Shahan & Podlesnik, 2005; 2008; Tomanari, 2004), it would appear to be a good time to assess the alternative account given by Lieberman et al Toward this end, we review and evaluate their argument and results, and then present some new data that would appear to support the conditioned‐reinforcement hypothesis in humans.…”

Observing responses of chain-schedule stimuli and effects of d-amphetamine and morphine

“…The next manipulation was to provide exposure to the chain and tandem schedules without the observing contingency. This is similar but not identical to training found in other studies on observing (e.g., Defulio & Hackenberg, 2008). These schedule changes occurred across sessions for D1 in which four sessions consisted of the presentation of the chain stimuli on the side key (i.e., S3-S2-S1 pairing condition) and then four sessions with just the tandem stimulus (white) on the side key.…”

“…The average observing rate producing each schedule-correlated stimulus during the last six stable sessions was compared across subjects. Observing rates were calculated by taking the total number of responses during the tandem stimulus and dividing by the time spent in the presence of the tandem stimulus (e.g., DeFulio & Hackenberg, 2008). The percentage of the session spent in the presence of each schedule-correlated stimulus (e.g., Shahan, 2002) during the last six stable sessions was compared across subjects.…”