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941.
Concurrent access to two concentrations of orally delivered phencyclidine: effects of feeding conditions. 总被引:1,自引:1,他引:0
M E Carroll 《Journal of the experimental analysis of behavior》1987,47(3):347-362
Two experiments addressed the effects of food satiation and deprivation on oral self-administration of two concurrently available phencyclidine concentrations. In the first experiment, 8 rhesus monkeys self-administered either of two concentrations of phencyclidine ("PCP, angel dust") and water under concurrent fixed-ratio 16 schedules. One concentration was always held constant (0.25 mg/mL) while a series of other phencyclidine concentrations, ranging from 0 (water) to 1.0 mg/mL, was presented in a nonsystematic order. Initially the monkeys were tested while food satiated, and the procedure was then repeated during food deprivation. The monkeys usually selected the higher concentration within the first few minutes of the session, indicating that taste and/or other immediate postingestional effects were important factors. Contrary to a number of previous reports, there were no consistent differences across subjects in the mean number of liquid deliveries or mean drug intake (mg/kg) during food satiation and deprivation. However, for all monkeys the within-session time course of responding during food satiation consistently differed from that during deprivation. A second experiment assessed whether the failure to find consistent differences in drug intake during food satiation and deprivation had been due to the history of concurrent access to different phencyclidine concentrations or to the extended experience with phencyclidine under food-satiation conditions. Six additional monkeys (Group 2) were exposed to the phencyclidine self-administration procedure (during food satiation and deprivation) for the same length of time as the monkeys in Experiment 1 (Group 1), except they received only concurrent access to phencyclidine (0.25 mg/mL) and water. Both groups then received concurrent access to phencyclidine and water during five repeated cycles of food deprivation and satiation. There were also marked individual differences in Group 2: During food satiation, 2 of the monkeys' responding increased, 1 showed no change, and 3 decreased. Examination of a number of historical variables indicated that the greater the percentage of total sessions spent during food satiation with phencyclidine available (before these experiments began), the greater the amounts of phencyclidine consumed during food satiation and the smaller the differences in phencyclidine intake when the two feeding conditions were compared. 相似文献
942.
This article deals with appropriate communication and interpersonal skills that nurses may use in order to support patients who are experiencing self-concept changes related to their health problems. Three areas of patient need related to self-concept are explored. The stages of adaptation to loss and the crucial task of grief work are reviewed, and nursing interventions designed to strengthen the self-concept and support patients as they adapt to loss are suggested. Sensitive communication, although a low-visibility nursing skill, is cited as critical in assisting the patient to achieve an optimum level of wellness. 相似文献
943.
The interaction of stimulus and reinforcer control in complex temporal discrimination. 总被引:2,自引:2,他引:0
Six pigeons were trained in a discrete-trials signal-detection procedure to discriminate between a fixed-duration stimulus (5 s or 20 s) and a set of variable durations ranging from 2.5 s to 57.5 s in steps of 5 s. For each fixed-duration stimulus, the ratio of reinforcer frequencies contingent upon reporting the fixed versus the variable stimulus was systematically manipulated. Detection performance was well controlled by both the stimulus value and the reinforcer ratio. Both the discriminability between the fixed duration and the set of variable durations, and the discriminability between the fixed duration and each of the variable durations, were independent of the reinforcer-frequency ratio when discriminability was measured as log d. The sensitivity of response bias to reinforcement-ratio changes was independent of the value of the fixed duration, but was not independent of the discriminability of the variable durations from the fixed durations. Under current models, discriminability measures in complex temporal discrimination may be independent of biasing manipulations, but bias measures are not independent of stimulus values. 相似文献
944.
Pigeons' choices between alternatives that provided different percentages of reinforcement in mixed schedules were studied using the concurrent-chains procedure. In Experiment 1, the alternatives were terminal-link schedules that were equal in delay and magnitude of reinforcement, but that provided different percentages of reinforcement, with one schedule providing, reinforcement twice as reliably as the other. All pigeons preferred the more reliable schedule, and their level of preference was not systematically affected by variation in the absolute percentage values, or in the magnitude of reinforcement. In Experiment 2, preference for a schedule providing 100% reinforcement over one providing 33% reinforcement increased systematically with increases in the duration of the terminal links. In contrast, preference decreased systematically with increases in the duration of the initial links. Experiment 3 examined choice with equal percentages of reinforcement but unequal delays to reinforcement. Preference for the shorter delay to reinforcement was not systematically affected by variation in the absolute percentage of reinforcement. The overall pattern of results supported predictions based on an extension of the delay-reduction hypothesis to choice procedures involving mixed schedules of percentage reinforcement. 相似文献
945.
Daniel E. Everitt M.D. 《Journal of religion and health》1987,26(2):92-96
The goals and ends of contemporary medicine are often unclear. An explicit inquiry into the religious dimensions of healing offers an important perspective from which to evaluate the potential capabilities of the medical profession. This paper describes a course in which medical students joined divinity students to explore areas of mutual intellectual, professional, and personal interest. Students and faculty examined in depth three broad areas in which medicine and religion share common ground: concepts of health and illness from the religious perspective, approaches to the understanding of suffering and meaning, and the shared professional stresses of physician and clergy.This paper comes from the Department of Medicine, Beth Israel Hospital, and the Division on Aging and the Program for the Analysis of Clinical Strategies, Harvard Medical School, and the West Roxbury-Brockton Veterans Administration Geriatric Research, Education and Clinical Center, Boston. 相似文献
946.
947.
The prediction of drug use among college students from MMPI, MCMI, and sensation seeking scales 总被引:1,自引:0,他引:1
This study examines the ability of five self-report assessment measures to predict college students' drug use across 12 pharmacological drug categories. Subjects were 125 female and 61 male university undergraduate students. The test battery included the following instruments: the Psychopathic Deviancy (Pd) scale of the Minnesota Multiphasic Personality Inventory (MMPI); the MacAndrew Alcoholism scale (MAC), a special scale of the MMPI; the Sensation Seeking Scale (SSS); the Millon Alcohol Abuse Scale; and the Millon Drug Abuse Scale. Scores from these instruments were utilized in linear combinations to predict individual drug use outcomes as well as polydrug versus single drug use patterns. The drug categories included in this investigation are coffee, tobacco, alcohol, marijuana, tranquilizers, depressants, amphetamines, LSD, other hallucinogens, solvents, narcotics, and cocaine. Results demonstrate significant and meaningful relationships between predictors and drug use levels among college students. Weighted equations derived from linear discriminant function analyses were generally capable of accurately classifying subject's drug use levels across drug categories and in discriminating single drug use from polydrug use patterns. Typically, the Sensation Seeking Scale entered as the most powerful predictor of substance use and abuse. 相似文献
948.
Rats were trained on concurrent schedules in which pressing one lever postponed shock and pressing the other occasionally produced a 2-min timeout during which the shock-postponement schedule was suspended and its correlated stimuli were removed. Throughout, the shock-postponement schedule maintained proficient levels of avoidance. Nevertheless, in Experiment 1 responding on the timeout lever was established rapidly, was maintained at stable levels on variable-interval schedules, was extinguished by withholding timeout, was reestablished when timeout was reintroduced, and was brought under discriminative control with a multiple variable-interval extinction schedule of timeout. These results are in contrast with Verhave's (1962) conclusion that timeout is an ineffective reinforcer when presented to rats on intermittent schedules. In Experiment 2 the consequence of responding on the timeout lever was altered so that the shock-postponement schedule remained in effect even though the stimulus conditions associated with timeout were produced for 2 min. Responding extinguished, indicating that suspension of the shock-postponement schedule, not stimulus change, was the source of reinforcement. By establishing the reinforcing efficacy of timeout with standard variable-interval schedules, these experiments illustrate a procedure for studying negative reinforcement in the same way as positive reinforcement. 相似文献
949.
Relative allocation on concurrent schedules can depend on schedule parameters when behavioral parameters are constant 总被引:1,自引:1,他引:0 下载免费PDF全文
Houston AI McNamara JM Sumida BH 《Journal of the experimental analysis of behavior》1987,47(1):127-131
We develop a simple model of switching between the initial links of a concurrent-chain procedure. Behavior is determined by four parameters μ1, μ2, q1, and q2. The first two are the basic rates of switching from Schedule 1 and Schedule 2, respectively. The second two are the probabilities of leaving Schedule 1 and Schedule 2 after the corresponding terminal link has been completed. We show that for fixed values of these four parameters, the relative allocation on the initial links may change as a result of changes in initial-link schedules. The effect can be quite large if the switching rates are low. An implication is that relative allocation is not necessarily a good measure of behavior. 相似文献
950.
McIntire KD Cleary J Thompson T 《Journal of the experimental analysis of behavior》1987,47(3):279-285
Two cynomolgous macaques categorized six colors into two groups of three after conditional discrimination training (zero-delay symbolic match-to-sample). The procedures resulted in the establishment of relations among the elements of each set-relations that were not specifically trained and that can be characterized by the properties of reflexivity, symmetry, and transitivity. Each set of colors was related to a characteristic pattern of responding: One response pattern involved temporal duration (press and hold the response keys); the second response pattern entailed repeated pressing and releasing of the response keys (fixed ratio 8). Six combinations of two colors were trained, three combinations from each set. After discriminative performance stabilized for each monkey, they were tested with 10 additional color combinations, all of which differed from the training combinations. The conditional relations established between test combinations can be characterized as stimulus equivalence. The training procedures were analogous to the procedure of using category names, and have implications for understanding the function of language in the formation of equivalence classes. 相似文献