William B. Pavlik

Analysis of the Partial Reinforcement Extinction Effect in Humans Using Absolute and Relative Comparisons of Schedules

The partial reinforcement extinction effect (PREE) was analyzed in humans using a quasi-multiple schedule of reinforcement with two discrete trial tasks. The first task was a videogame analog of a shuttle box. Using a joystick, subjects were required to move a cue in one of four directions for reinforcement. The second was a simple concept-formation task consisting of two binary dimensions; responding to one of the four alternatives was reinforced. All subjects were trained on the two tasks on a randomly alternating basis. Two groups were trained on the tasks using either continuous or partial reinforcement schedules for both tasks. An additional two groups received both schedules of reinforcement with continuous reinforcement on

Within- and between-subjects partial reinforcement effects with an autoshaped response using Japanese quail (Coturnix coturnix japonica)

Animals exposed to schedules of partial reinforcement are typically more resistant to extinction than are animals trained with continuous reinforcement. This is the partial reinforcement effect (PRE). Animals experienced with both partial and continuous schedules are often more persistent on the continuous schedule, yielding a reversed PRE. Both conventional and reversed PREs have been elusive with classical conditioning paradigms. The present experiment attempted to demonstrate between- and within-subject PREs using 50% and 100% autoshaping schedules. Presence or absence of a PRE depended on the behavioral measures used. Marked terminal group differences in acquisition produced a between-subjects PRE with absolute response levels but not with rate-of-change measures. Within subjects, only choice trial comparisons were sensitive enough to differentiate the two schedules. Acquisition data were inconsistent with most of the classical conditioning PRE literature, but consistent with results reported in the autoshaping literature. These discrepancies may reflect the operant-classical interaction in autoshaping.

Analysis of the Partial Reinforcement Extinction Effect in Humans as a Function of Sequence of Reinforcement Schedules

The present experiment was conducted to investigate the effects that changes in reinforcement schedule have on the persistence of learned responses. Human subjects learned two simple tasks concurrently, both tasks being under either continuous reinforcement (CRF) or partial reinforcement (PRF). After 50 acquisition trials on both tasks, half the subjects in each schedule condition received an additional 50 acquisition trials with the same reinforcement schedules on the two tasks. The remaining subjects received 50 additional trials with the opposite reinforcement schedule on both tasks. All subjects then received 50 extinction trials on both tasks. The extinction data were biphasic, consisting of a short-term phase of declining performance in which group differences were clear, followed by a long-term phase in which the groups converged to a uniform high level of persistence. A conventional partial reinforcement effect was observed during the short-term phase, but only in terms of the most recently experienced schedule, that is, the first schedule experienced appeared to have no effect upon persistence, contrary to some current theories of the partial reinforcement effect. The role of task demands in this type of research is discussed.

The effects of age, exposure, preexposure, and noise conditions on variable interval performance

The present study was designed to investigate the differential effects of environmental factors on performance in young and aged rats. Specifically, within- and between-session habituation, environmental preexposure, and noise conditions were examined. Consistent age differences were found in response to environmental change and sensory condition. Variable-interval response rates of the well-habituated old animal were well below those of the young. Stimulus change and increments in noise elevated these behaviors in the aged to levels well above those seen in the young. Aged animals appeared incapable of maintaining higher response rates without corresponding conditions of novelty, contextual change, or increments in ambient sensory conditions. Preexposure to sensory conditions similar to those used in the operant chamber reduced response rates in the old, as did habituation with repeated exposure to the chamber.

Conventional and reversed partial reinforcement effects in human operant responding

Acquisition and extinction of button pressing on multiple schedules of continuous-continuous (CRF/CRF), variable ratio n-variable ratio n (VRn/VRn), and CRF/VRn schedules of reinforcement were examined using human subjects. In contrast to similar animal studies, responding during acquisition was consistently higher on CRF schedules relative to VR groups and components. Extinction data for between-subject comparisons of schedules showed typical partial reinforcement effects (PREs). Within-subject comparisons revealed small but reliable reversed partial reinforcement effects (RPREs). These data extend the findings of the RPRE in nonhuman animals to humans. The validity of the PRE as a universal generalization for extinction phenomena is examined and rejected.

The persistence of learned behaviors in humans as a function of changes in reinforcement schedule and response

Abstract The present experiments were conducted to investigate the effects which changes in reinforcement schedule and criterion response have on the persistence of learned responses. In Experiment 1, subjects were required to learn concurrently two tasks. Both tasks involved making one of four possible responses for reinforcement. During the first acquisition phase subjects received either continuous (CRF) or partial (PRF) reinforcement for both tasks. At the start of the second acquisition phase, the criterion response for both tasks was changed. In addition, reinforcement schedules were altered such that some subjects experienced (a) the same schedule of reinforcement as in Phase 1 on both tasks, (b) the alternate schedule of reinforcement on both tasks (i.e., CRF to PRF, and PRF to CRF), or (c) a change in schedule of only one task (e.g., CRF on one task and PRF on the other) during Phase 2. Following Phase 2 all reinforcement was withheld, and the persistence of the most recently learned response was monitored. It was found that subjects who had received CRF during Phase 1 evidenced a conventional partial reinforcement extinction effect (PREE) when they received only CRF or PRF during Phase 2, whereas subjects receiving both schedules evidenced a generalized PREE. However, there were no significant differences among groups receiving PRF during Phase 1. In the second experiment, a comparison of resistance to extinction was made between continuous and partial reinforcement schedules with and without a change in the criterion response. The results demonstrate that a change in criterion response diminished the level of persistence of the most recently learned response. The data are reviewed with reference to current theories of persistence and to the extinction-induced resurgence phenomenon.

An Objective and Functional Matrix for Introducing Concepts of Reinforcement and Punishment.

Although the operant approach to psychology is based on objective empirical observations and is descriptive in nature, much of psychology is filled with subjective, interpretive terminology. Such terminology produces confusion over the definitions of basic operant concepts. We suggest a solution that defines the concepts of positive and negative reinforcements and punishments in an objective fashion. Our 2 × 2 matrix avoids the subjective terminology often used in such matrices.

Effects of A Masking Task on Schedule Discrimination and Extinction in Humans

Humans were exposed to a multiple fixed-interval 20- s/variable-ratio 15 schedule of lever pressing, with an anagram solution task, the “masking task, ” either concurrent with, or alternating with the operant task. In Experiment 1, subjects with the concurrent anagram task, the “masked” subjects, did not discriminate between the different components of the operant task. Subjects with the alternating anagram task, the “unmasked” subjects, did discriminate between the two components of the operant task. In Experiment 2, the operant response rates of the masked subjects did not decline during extinction of operant responding. the response rates of the unmasked subjects declined greatly during extinction. In Experiment 3, only masked subjects were run and both the operant task and the anagram task were put on extinction. Operant response rates and anagram response rates did not decline during extinction. Experiment 4 alternated masked and unmasked operant sessions in counterbalanced fashion across different subjects. Results replicated Experiments 1, 2, and 3, and some subjects developed discriminative responding during the unmasked sessions which was maintained during subsequent masked responding. The behavior of the subjects during the present experiments is likely to be controlled by: implicit task demands, explicit task demands (i.e., Instructions), attended-to reinforcement contingencies, and contingency-related subject-produced verbal rules.

Resistance to extinction in humans: Analysis of the generalized partial reinforcement effect

Abstract The effects of various probabilities of reinforcement on the persistence of learned behaviors were examined to investigate the generalization of persistence effects and other aspects of extinction behaviors observed in humans. Subjects were required to perform two tasks concurrently. Both tasks required the subject to make one of four responses for reinforcement. Performance for each task was reinforced using one of three schedules of reinforcement: 100, 60, or 40% probability of contingent reinforcement. Three of the groups received the same schedule of reinforcement for both tasks, (groups 100 100 , 60 60 , and 40 40 ). The other six groups experienced a combination of two different schedules (groups 100 60 , 60 100 , 100 40 , 40 100 , 60 40 , and 40 60 ). Both acquisition and extinction data suggest that there is a generalization of persistence across tasks. The data also confirm the presence of different extinction phases for tasks of this type, a short-term and a long-term phase. The short-term phase is characterized by a decrease in responding that is inversely related to reinforcement schedules. During the long-term phase, the rate of responding remained above chance levels, and a reemergence of the formerly reinforced response was observed as extinction continued. The duration of these phases appears to be related to the average of reinforcement schedules experienced in acquisition.

Between-and within-subjects PRE with sucrose incentives

This experiment was designed to test the generality of the between- and within-subjects partial reinforcement effect (PRE) with sucrose solutions as the reinforcer and female hooded rats as subjects in a free-operant leverpress situation. Twenty subjects were given 10 sessions of acquisition training with (1) CRF only, (2) PRF only, or (3) MULT CRF-PRF. Comparisons of responding during 3 days of extinction between subjects receiving only one schedule resulted in a conventional PRE with significant differences between the two groups on Day 1 of extinction, whereas the within-subjects comparison yielded a reversed PRE with significant differences between responses to the signal associated with CRF and PRF on Day 1 and Day 2 of extinction.