Modifying drug-reinforced behavior by altering the economic conditions of the drug and a nondrug reinforcer.

Six rhesus monkeys were trained to self-administer orally delivered phencyclidine (0.25 mg/mL) and saccharin (0.03% wt/vol) under concurrent fixed-ratio 16 schedules. In Condition 1 the fixed-ratio requirement for phencyclidine was changed from 16 to 4, 8, 16, 32, 64, 128 and 16 while the fixed-ratio requirement for saccharin deliveries remained constant at 16. In Condition 2 the fixed-ratio value for saccharin was systematically altered while the fixed-ratio requirement for phencyclidine remained at 16, and in Condition 3 the fixed-ratio requirements for both phencyclidine and saccharin were altered simultaneously. Water was then substituted for saccharin, and the series of fixed-ratio manipulations was replicated. The phencyclidine concentration was reduced to 0.125 mg/mL and Conditions 1 and 3 were repeated. When the fixed-ratio requirement for phencyclidine was increased and the fixed-ratio requirement for saccharin or water remained fixed at 16, phencyclidine deliveries decreased when saccharin (vs. water) was concurrently available. The magnitude of the decrease ranged from 20% to 90% (of the concurrent water condition) as the fixed-ratio requirement for phencyclidine increased from 4 to 128. When the fixed-ratio requirement for phencyclidine remained at 16 and the fixed-ratio requirements for concurrent saccharin or water varied between 4 and 128, phencyclidine deliveries decreased by 30% to 40% due to the concurrent availability of saccharin (vs. water). This decrease occurred only at the three lowest fixed-ratio values when saccharin intake was relatively high. When the fixed-ratio requirements for both phencyclidine and concurrent saccharin or water were varied simultaneously, phencyclidine deliveries were reduced from 20% to 45% when saccharin (vs. water) was concurrently present. There was little effect of reducing the phencyclidine concentration when the data were analyzed in terms of unit price (responses per milligram). Thus, changes in the fixed-ratio requirement or drug concentration were functionally similar, and unit price of phencyclidine was the variable that was influenced by the presence of concurrent saccharin. These data indicate that drug-reinforced behavior is substantially reduced when the environment is enriched with an alternative nondrug reinforcer. The economic context in which these substances are presented is an important determinant of drug-reinforced behavior.     

Using Brief Functional Analysis to Select Interventions for Oral Reading

Reading interventions were applied in a brief multielement format to examine their effectiveness at improving the oral reading fluency of three students referred for reading problems. Although each student had different profiles across experimental analyses, effective interventions were identified and a mini-replication confirmed the pattern of results in each case.     

Oral contraceptive use among African American adolescents: Individual and community influences

Side effects of oral contraceptives are a noteworthy problem, particularly among low-income young women who reside in inner-city communities. The problem may be compounded by inadequate family planning services, particularly when such services are provided by general medical practices with high volumes of clients. This study examined the prevalence and correlates of pill-related side effects, with particular attention to the role of clinic characteristics. Participants were 177 pregnant and parenting African American adolescents and young women (average age=18.34). The experience of a pill-related side effect was the most frequently cited barrier to birth control use, and it was significantly related to contraceptive behavior. Finally, although participants attending comprehensive clinics experienced more barriers to medical service use than those attending neighborhood clinics, they reported fewer problems with pill-related side effects and better psychological functioning. Implications for future research and policy are discussed. This study was completed with the assistance of grants from the Illinois Department of Alcoholism and Substance Abuse, the National Institute of Child Health and Human Development, and the Office of Research on Women's Health to Jean Rhodes. Portions of this paper were presented at the 1993 Biennial Meeting of the Society for Community Research and Action, Williamsburg, Virginia. The authors gratefully acknowledge the assistance of Julian Rappaport, Joel Meyers, Hope Landrine, Lori Ebert, the Reverend Annette Collins, Margaret Daniels, Khya Lawrence, and the professionals and participants at the service settings.     

Oral self-administration of pentobarbital by rhesus monkeys: maintenance of behavior by different concurrently available volumes of drug solution.

For 4 rhesus monkeys, mouth-contact responses with either of two brass spouts were reinforced according to fixed-ratio schedules by 0.65-mL liquid deliveries during daily 3-hr sessions. Three experiments were conducted. In each experiment, independent fixed-ratio schedules were concurrently in effect at the two spouts. Following completion of each fixed ratio on a spout, a specified number of liquid deliveries were available from that spout under a continuous-reinforcement schedule. The number of such deliveries available at each spout was manipulated independently. In Experiment 1, a 1-mg/mL pentobarbital solution was simultaneously available with water (the drug vehicle) under concurrent fixed-ratio schedules of 32 responses for 3 subjects and 64 responses for the remaining subject. The number (N) of liquid deliveries that were available after completion of each fixed ratio was varied in the following order: 8, 4, 2, 1, and 8 (retest). For each subject at each condition, drug maintained more responding than water. The number of drug deliveries obtained per session was directly related to the amount of drug available per fixed ratio (i.e., to N), whereas the number of fixed ratios completed per session generally was inversely related to the value of N. In Experiment 2, fixed-ratio size was the same for each subject as in Experiment 1, but deliveries of a 1-mg/mL pentobarbital solution were available at both spouts. The number of drug deliveries available under one fixed-ratio schedule (Ns, the "standard" reinforcer amount) was held at eight, and the number of drug deliveries available under the second schedule (Nc, the "comparison" reinforcer amount) was changed across blocks of six sessions of stable responding in the following order: 1, 2, 4, 8, 4, 2, and 1. The identical series of comparison reinforcer amounts (Nc) was then tested twice more, but with the standard reinforcer (Ns) held first at four and then at two deliveries. Across the three choice series, reinforcing effects were directly related to reinforcer magnitude. In Experiment 3, deliveries of a 1-mg/mL pentobarbital solution again were available at both spouts. However, the two reinforcer amounts were held constant at N = 8 deliveries under one schedule and N = 4 deliveries under the second schedule, and fixed-ratio size was systematically varied. Across the range of fixed-ratio sizes from low to high, the degree to which behavior was better maintained by the larger of the two drug quantities was an inverted U-shaped function of fixed-ratio size.(ABSTRACT TRUNCATED AT 400 WORDS)     

Concurrent phencyclidine and saccharin access: presentation of an alternative reinforcer reduces drug intake.

Six monkeys self-administered orally delivered phencyclidine ("angel dust") and saccharin under concurrent fixed-ratio 16 schedules during daily three-hour sessions. Liquid deliveries were contingent upon lip-contact responses on solenoid-operated drinking spouts. Three saccharin concentrations (0.003%, 0.03% and 0.3%, wt/vol) were tested in a nonsystematic order. For each saccharin concentration, the following series of phencyclidine concentrations (mg/ml) was presented: 0.25, 0.5, 1, 0.25 (retest), 0.125, 0.0625, 0.0312, 0.25 (retest) and 0 (water with stimuli signaling phencyclidine). As the saccharin concentration increased, the number of drug deliveries decreased, and the peaks of the concentration-response functions were shifted to the right. The lowest saccharin concentration (0.003%, wt/vol) maintained responding in excess of phencyclidine levels in only one monkey. The two higher saccharin concentrations maintained behavior far in excess of phencyclidine, but saccharin deliveries decreased in some monkeys as phencyclidine concentration and intake (mg/kg) increased. The time course and patterns of phencyclidine-reinforced responding were also altered when saccharin was concurrently available. The results are discussed in terms of strategies to reduce drug-reinforced behavior, preference between different reinforcers, and measures of reinforcing efficacy.     

The influence of surgical stress,anxiety and benzodiazepine intravenous sedation on recall of oral surgery

Abstract

This study, part of a larger investigation of the efficacy and safety of intravenous sedation in dentistry, reports the prevalance of failure to recall information during third molar impaction surgery and attempts to differentate the effects of stress and benzodiazepines on recall. Both recognition of neutral pictures and the recall of surgical procedures were assessed. Recall failure in the drug groups ranged from zero for recall of stressful procedures, completed before drug titration, to 92 percent of subjects for recognition of the neutral picture presented at 5 minutes after the surgical procedure began. Placebo condition subjects had almost no recall loss. Recall failure was demonstrated to be primarily a function of the volume of midazolam employed. However, operative stress and trait and state anxiety explained some of the findings.     

FPG联合选择性OGTT模式在糖尿病筛查中的应用研究

探索空腹血糖(FPG)和选择性口服葡萄糖耐量试验(OGTT)相结合的糖尿病(DM)筛查模式。应用OGTT对无DM史人群行DM筛查,运用ROC曲线评价FPG对DM、IPH的诊断价值。FPG切点为7.0mmol/L时,诊断DM的敏感性为69%,特异性为100%;FPG切点为5.6mmol/L时,诊断IPH的敏感性为100%,特异性为83.3%。对FPG初筛在5.6mmol/L～6.9mmol/L者行OGTT,可在保证筛查准确性的基础上,最大程度节约成本。     

幼儿书目清单的编制及其与口头词汇的关系

本研究根据中国家庭文化背景编制一个测量中国家庭亲子阅读量的问卷——幼儿书目清单,并比较书目清单和传统的父母自陈报告家庭亲子阅读频率这两种方法在预测幼儿口头词汇的效果上是否存在差异.研究发现幼儿书目清单有较好的信、效度.进一步的回归分析发现在控制了儿童的智商、父母的学历后亲子阅读量确实能显著预测幼儿的口语能力,并且书目清单的预测效果优于父母自陈报告的亲子阅读频率.     

儿童英汉口语词汇知识与英语语音意识的关系

以120名母语为汉语的四、五年级小学儿壹为被试.探讨英语和母语口语词汇知识与英语语音意识的关系.结果表明: (1)英语和母语口语词汇知识与英语语音意识之间存在密切关系. (2)英语口语词汇产生对英语音节、首音一韵脚和音位意识具有显著的独立预测作用,英语口语词汇理解对英语语音意识的独立贡献性不显著. (3)汉语口语词汇产生对英语音节意识具有显著的预测作用,汉语口语词汇理解对英语音位意识具有显著的预测作用;汉语口语词汇产生既可以直接作用于英语音节意识,也可以通过汉语语音意识的中介发挥间接作用:汉语口语词汇理解则完全通过汉语语音意识和英语口语词汇产生的中介间接作用于英语旨位意识.