For experiments investigated the effect of adding noncontingent (free) food to an operant contingency during random ratio (RR) and random interval (RI) training and during extinction in rats. Free food was presented during extinction of RI responding in Experiments 1 and 2. Noncontigent food retarded response loss compared to a signaled free food group (Experiments 1 and 2) which declined less rapidly than a control group of no free food (Experiment 1). Free food was presented while the instrumental reinforcement RR and RI probabilities remained unchanged in Experiments and 3 and 4. In contrast to Experiments 1 and 2, added noncontingent food facilitated response loss compared to a signaled condition and to a control group of no added free food which responded most (Experiment 3). Removing all food caused most recovery in the free food group, less in the signaled condition and least in the control group (Experiments 1 and 3). A generalization decrement hypothesis of the free food effect was offered to explain these apparently paradoxical results.

The blocking effect is the reduced stimulus control achieved by an unfamiliar (target) stimulus, “X”, when it is paired during conditioning with a stimulus, “A”, that already has acquired control. Blocking has been relatively difficult to accomplish with nonverbal behavior in human participants, compared with either nonverbal behaviour in animals or verbal behaviour in humans. Thus my primary research purpose was to produce blocking in the nonverbal, operant behaviour of human participants. My secondary research purpose was to achieve blocking of verbal behaviour. My third research purpose was to evaluate the relationship between verbal and nonverbal results. Four experiments were conducted with introductory psychology students pressing keys in response to coloured stimuli on a computer monitor. In Experiments 1A and 1B, the blocking procedure was applied only to the negative discriminative stimulus (S−) which was paired with a response-cost contingency. Stimulus colours employed as the preconditioned and target stimuli were counterbalanced between Experiments 1A and 1B. Statistically significant results were obtained in the first case, but not in the second. Overshadowing likely occurred in both experiments, adding to blocking effects in Experiment 1A and subtracting from blocking effects in Experiment 1B. In Experiments 2A and 2B, overshadowing was better controlled and the blocking procedure was applied to both positive (S+) and negative (S−) stimuli. The key finding was blocking in Experiment 2B, with a large, statistically significant difference in response rates during the positive target stimulus. The success of blocking in Experiment 2B likely was a consequence of the powerful point-loss contingency employed with the negative stimulus, which greatly reduced the probability of generalized high-rate responding. It appears to be the first demonstration of blocking of a positive stimulus in an operant procedure employing human participants; it supports the continuity of learning principles across species. Verbal response measures in both Experiments 2A and 2B also suggested that blocking occurred. In Experiment 2A however, nonverbal measures failed to show blocking, suggesting that in humans verbal measures may be more sensitive to blocking manipulations than are nonverbal measures.

The blocking effect is the reduced stimulus control achieved by an unfamiliar (target) stimulus, “X”, when it is paired during conditioning with a stimulus, “A”, that already has acquired control. Blocking has been relatively difficult to accomplish with nonverbal behavior in human participants, compared with either nonverbal behaviour in animals or verbal behaviour in humans. Thus my primary research purpose was to produce blocking in the nonverbal, operant behaviour of human participants. My secondary research purpose was to achieve blocking of verbal behaviour. My third research purpose was to evaluate the relationship between verbal and nonverbal results. Four experiments were conducted with introductory psychology students pressing keys in response to coloured stimuli on a computer monitor. In Experiments 1A and 1B, the blocking procedure was applied only to the negative discriminative stimulus (S−) which was paired with a response-cost contingency. Stimulus colours employed as the preconditioned and target stimuli were counterbalanced between Experiments 1A and 1B. Statistically significant results were obtained in the first case, but not in the second. Overshadowing likely occurred in both experiments, adding to blocking effects in Experiment 1A and subtracting from blocking effects in Experiment 1B. In Experiments 2A and 2B, overshadowing was better controlled and the blocking procedure was applied to both positive (S+) and negative (S−) stimuli. The key finding was blocking in Experiment 2B, with a large, statistically significant difference in response rates during the positive target stimulus. The success of blocking in Experiment 2B likely was a consequence of the powerful point-loss contingency employed with the negative stimulus, which greatly reduced the probability of generalized high-rate responding. It appears to be the first demonstration of blocking of a positive stimulus in an operant procedure employing human participants; it supports the continuity of learning principles across species. Verbal response measures in both Experiments 2A and 2B also suggested that blocking occurred. In Experiment 2A however, nonverbal measures failed to show blocking, suggesting that in humans verbal measures may be more sensitive to blocking manipulations than are nonverbal measures.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1974. / Bibliography: leaves 99-105. / vi, 105 leaves ill

Thesis (B.A. Hons. 1976) from the Department of Psychology, University of Adelaide.

Thesis (M.S.)--University of Wisconsin--Madison, 1973. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The present study attempted to investigate the effects of food-deprivation and pretest experience on operant level bar pressing. In addition, these effects were assessed over an extended number of sessions. Thirty male albino rats were assigned to two major conditions; one which received pretest experience in the experimental chambers for 15 sessions and one which did not. Ss in the major conditions were then factorially assigned to three feeding schedules; one an ad lib. or no deprivation schedule, one a 15 gm. or mildly deprived schedule, and one a 5 gm. or severely deprived schedule. All Ss were then placed in the experimental chambers for 15 sessions. The results indicated that Ss which had no pretest experience exhibited decreased responding as a function of deprivation, while following pretest experience deprivation Ss’ operant level. In addition, operant level fluctuated widely over sessions. It was concluded that the present results integrated the findings of other investigators working on operant level. / Arts, Faculty of / Psychology, Department of / Graduate

I attempt in this paper to develop a theory of paternalism which indicates when and why a paternalistic action is justified. In the first two chapters I consider the extant theories on this subject: in the first chapter I develop a utilitarian theory of the justification of paternalistic interference, and in the second chapter I consider various non-utilitarian theories that have been offered. Although I do not agree with the utilitarian analysis of rights, and so with their rationale for paternalistic intervention, I argue that such a theory does provide a strong presumption against such interference. Nor do I find any of the non-utilitarian theories satisfactory, although they each contain certain important insights. In the third chapter I develop my own theory. I claim that there is really only a problem in justifying paternalism when the subject has the prima facie right to do what he proposes to do. It is therefore necessary to determine under what conditions any prima facie right can be interfered with. From results of this investigation I conclude that consent, either tacit or explicit, prior or subsequent to interference, is the key to the justification of paternalistic interference. More specifically, I argue that consent, or the disposition to consent upon receipt of factual information or correction of a logical error, is a necessary condition for justification, and that it is also sufficient except where it is gained by "warping" the subject's preferences, or where it is due to lack of relevant information, or a logical error. / Arts, Faculty of / Philosophy, Department of / Graduate

No description available.

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.