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The variables affecting social behavior are myriad, making the prediction and control of behavior occurring in social contexts relatively difficult. One can attempt to create a controlled social context in the laboratory by introducing a second organism into an operant chamber. To investigate effects of social stimuli on operant responding, key pecking responses of three pigeons were maintained on a variable-interval (VI) schedule of reinforcement in Experiment 1, and the key pecking responses of three additional pigeons were maintained on a three-component multiple schedule in Experiment 2. The components included a variable-ratio (VR) schedule, a fixed-interval (FI) schedule, and a differential reinforcement of low rate behavior (DRL) schedule. No social stimuli were present in the operant chamber during the baseline conditions of either experiment. During experimental conditions a mirror was introduced into the operant chamber to simulate the presence of another organism. The mirror covered one side wall of the chamber adjacent to the work panel containing the response key. Relative decreases in rates of responding were observed during each experiment when the pigeons had access to their reflections compared to when no mirror was present. Response rates returned to baseline levels when the mirror was removed in the subsequent conditions, suggesting that access to visual-social stimuli disrupted pigeon behavior controlled by different schedules of reinforcement.

This study attempts to experimentally manipulate core constructs of the Health Belief Model (HBM) and the Theory of Planned Behavior (TPB) in order to increase condom use behavior. A direct comparison of the two models to determine the theory that best explains condom use behavior change will also be attempted. University of New Mexico psychology students (N = 280) completed measures on perceived susceptibility, severity, benefits, barriers, condom use self-efficacy, attitudes toward condoms, subjective norms, and perceived behavioral control. Next, they completed one of three randomly assigned computer-based interventions. 218 (77.8%) completed a behavioral assessment one month later. The TPB was best at explaining risky sexual behavior at baseline; it explained 30.6% of the variance while the HBM only explained 1.5% of the variance. The interventions were able to manipulate every predictor but perceived barriers. Mediational analyses of the HBM revealed that intervention type had an effect on perceived susceptibility, benefits, barriers, and condom use self-efficacy, but none of these mediators predicted risky sexual behavior at follow-up. TPB mediators attitudes toward condom use and subjective norms were influenced by intervention type. Subjective norms and perceived behavioral control predicted intentions, but intentions did not predict behavior at follow-up. This study supports the assertion that theory-based interventions are more effective at changing proposed mediators of behavior; however, it was not successful at eliciting behavior change. In sum, current behavior theories should be rigorously examined and modified if need be to create more comprehensive theories of behavior change.

Vinclozolin (Vz) is one member of a group of fungicides whose metabolites are androgen receptor antagonists. These fungicides have been shown to block androgen-driven development and compromise reproductive function. The current study sought to determine if Vz also affects learning following exposure to low doses during the perinatal period. To test this, an androgen-dependent behavior was examined, the extinction of a previously reinforced running response. Pregnant Long–Evans rats were administered a daily oral dose of 0, 1.5, 3, 6 or 12 mg/kg Vz from the 14th day of gestation through postnatal day 3. After reaching adulthood, male and female offspring were trained to run through a short alleyway for food reinforcement. Acquisition of the response was not affected by Vz exposure. However, males required more trials than females for response extinction once food was no longer available in the apparatus. Males exposed to 6 or 12 mg/kg Vz failed to show any extinction by the end of the procedure, while the lowest dose of Vz appeared to facilitate extinction in both male and female offspring. These results demonstrate that endocrine disrupting antiandrogens can alter nervous system development in addition to the reproductive system.

The present series of studies examined effects of MK-801, an NMDA antagonist, on short-interval timing in rats. The first study used two experiments to examine timing performance using the peak-interval (PI) and PI-gap procedures during chronic exposure of MK-801. The first of these experiments investigated the effects of three MK-801 doses (0.025 mg/kg, 0.05 mg/kg, & 0.2 mg/kg) administered for 10 sessions; the second experiment examined a single dose (0.2 mg/kg) administered for 15 sessions. MK-801 interfered with short interval timing by producing an over-estimation of time and a non-scalar increase in variability. Additionally, MK-801 increased response rate, suggesting a decrease in response inhibition. The influence of MK-801 on the formation of temporal memories was examined by switching the temporal criterion (Meck, 1988; Meck, Komeily-Zadeh, & Church, 1984). Spontaneous alternation and water maze tasks were determined whether the dose of MK-801 (0.05 mg/kg) also influenced spatial memory. Results suggested that MK-801 did not alter temporal learning and that this dose (0.05 mg/kg) had no effect on spontaneous alternation and water maze. MK-801 did increase the rate of responding, demonstrating that the drug had positive effects. However, the dose may have been insufficient to alter both spatial and temporal learning. Therefore, more work needs to be done with high concentrations of MK-801 before concluding that NMDA receptor antagonists have no influence on the learning of temporal durations. Finally, modeling simulations were used to qualitatively fit the MK-801 data using Scalar Expectancy Theory (SET) in order to better understand the effects of MK-801 on timing and temporal processing. Modeling results suggest MK-801 has a wide ranging effect on the mechanisms of timing and temporal processing. Based on the simulations, the best fit to the data was obtained when five of the eight parameters were altered. Clock speed was slowed, while variability of clock speed, memory transformation, threshold, and base-rate of responding values were all increased. In summary, no definitive conclusions can be made about MK-801 effects on temporal learning. However there are two clear effects on timing and temporal processing, MK-801 causes an over-estimation of time and an increased rate of responding.

Research shows that human operant behavior typically differs from non-human operant behavior on schedules of reinforcement. These differences in performance may be related to differences between the experimental preparations used to study human and non-human operant behavior. One such difference is the type of reinforcer used. This experiment analyzed the differential effects of points alone, points backed up by money, and sounds on schedule performance of human subjects. Results show that sounds generated moderate rates of responding, capable of change in either direction. When points backed up with money were the reinforcers, however, high rates of behavior were generated, disrupting the previously established baseline performance. This suggests that while points may be effective in generating high rates of behavior, they may be ineffective in producing sensitive baselines needed to study human operant behavior on schedules of reinforcement.

Although previous research has shown the efficacy of self-control techniques such as self-monitoring and self-reinforcement in changing study behavior, the adequacy of the experimental procedures utilized in many studies may be questioned. This experiment re-examined the effects these operant conditioning procedures had on the study behavior of junior college evening students by using three groups of subjects exposed to different combinations of self-control techniques. Control Group subjects recorded their new thoughts (ideas relating the course material to their everyday lives) in an attempt to control for the effects of novel procedures, motivation and other non-specific variables. Self-Monitoring Group subjects complied with the control procedure, monitored their study time {by recording study start and stop times) and monitored the number of facts learned (by self-administering quizzes). The Self-Reinforcement Group complied with the self-monitoring procedures and self-reinforced their study behavior (by listing their reinforcers, the cost per reinforcer in minutes of study time and recording the number of reinforcements received). Additional data collected consisted of concurrent weekly quiz scores, final examination scores and the extent to which subjects complied with the treatment procedures. Results showed no significant differences among the three groups on either concurrent quizzes or on the final examination. The Self-!

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