Discrete-trial choice in pigeons: Effects of reinforcer magnitude

The preference of pigeons for large reinforcers which occasionally followed a response versus small reinforcers which invariably followed a response was studied in a discrete-trial situation. Two differently colored keys were associated with the two reinforcement alternatives, and preference was measured as the proportion of choice trials on which the key associated with uncertain reinforcement was pecked. A combination of choice and guidance trials insured that received distributions of reinforcement equalled the scheduled distributions. For five of six subjects, preference for the uncertain reinforcer appeared to be a linear function of the magnitude of the certain reinforcer. In addition, there was greater preference for the response alternative associated with uncertain reinforcement than would be expected on the basis of net reinforcer value.     

Autoshaped responding: A baseline for studying stimulus preference

In an autoshaping procedure with pigeons, trials consisted of the illumination of two keys, each with a different color, and then a response-independent feeder operation. Over successive conditions, all key-color pairs were arranged from the set of amber, red, green, and blue lamps. During sessions with a given pair, the left-right configuration of the colors varied irregularly, and the two colors alternated in illuminating the feeder. With one red and one green key, for example, red appeared sometimes on the left and sometimes on the right, and the feeder was alternately lit red or green on successive trials. Both total pecks and proportion of trials with at least one peck on a key of a given color were generally greater for red and amber than for green and blue, and relations among preferences were generally transitive across different color pairs. Repeating the procedure with decreased red and amber intensities and increased green and blue intensities reduced red and amber pecking relative to green and blue pecking, implying that differences in responding were determined more strongly by intensive than by chromatic properties of the stimuli.     

Ethical aspects of the safety of medicines and other social chemicals

The historical background of the discovery of adverse health effects of medicines, food additives, pesticides, and other chemicals is reviewed, and the development of national and international regulations and testing procedures to protect the public against the toxic effects of these drugs and chemicals is outlined. Ethical considerations of the safety evaluation of drugs and chemicals by human experimentation and animal toxicity studies, ethical problems associated with clinical trials, with the falsification of clinical and toxicological data, and with inadequate experimental methodology, are reviewed, and the ethics of the marketing of drugs and their post-marketing surveillance, are similarly considered. These ethical problems are illustrated with many specific examples, including the drugs neoarsphenamine, chloramphenicol, thalidomide, diethyl stilboestrol and benoxaprofen.     

Design of randomized controlled trials: Principles and methods applied to a treatment for early stuttering

The “gold standard” methodology for treatment efficacy research is the randomized controlled trial (RCT), which is used extensively in medical research and in other areas such as psychology. Results from a well designed and conducted RCT, which show a new treatment to be clinically and statistically superior to current standard practice, can lead to a change in clinical practice. This paper presents a tutorial on RCTs, presenting and discussing the following principles and methods: the trial protocol, choice of control treatment, eligibility criteria, random allocation, outcomes and hypotheses, sample size, subject recruitment, analysis by intention to treat, interim analysis, stopping rules, safety data monitoring/trial management, and study documentation. RCTs are a complicated and logistically involved methodology. Hence, prior to the commitment of resources to such a trial in the development of a new treatment, the safety and clinical promise of the new treatment needs to be demonstrated with preliminary studies. Such preliminary studies have been completed for the Lidcombe Program (LP) of early stuttering intervention, and an RCT of that treatment is being conducted at the time of writing. The principles and methods of RCTs are illustrated with reference to that study.

Educational objectives: The reader will understand the design principles and methods of RCTs. The reader will understand the logistics of conducting a RCT of a treatment for early stuttering.     

COMPARISON OF DATA‐COLLECTION METHODS IN A BEHAVIORAL INTERVENTION PROGRAM FOR CHILDREN WITH PERVASIVE DEVELOPMENTAL DISORDERS: A REPLICATION

Cummings and Carr (2009) compared two methods of data collection in a behavioral intervention program for children with pervasive developmental disorders: collecting data on all trials versus only the first trial in a session. Results showed that basing a child's progress on first‐trial data resulted in identifying mastery‐level responding slightly sooner, whereas determining mastery based on all trials resulted in slightly better skill maintenance. In the current replication, no such differences in indication of mastery or maintenance were observed when data were collected on all trials or the first trial.     

Polish Research Ethics Committees in the European Union System of Assessing Medical Experiments

The Polish equivalents of Research Ethics Committees are Bioethics Committees (BCs). A questionnaire study has been undertaken to determine their situation. The BC is usually comprised of 13 members. Nine of these are doctors and four are non-doctors. In 2006 BCs assessed an average of 27.3 ± 31.7 (range: 0–131) projects of clinical trials and 71.1 ± 139.8 (range: 0–638) projects of other types of medical research. During one BC meeting an average of 10.3 ± 14.7 (range: 0–71) projects of medical research were assessed (2006). The amendment of Polish laws according with Directive 2001/20/EC caused a percentage increase in BCs which assessed less than 20 projects per year (16% vs. 33% or 42% in 2003 vs. 2005 or 2006 respectively, p < 0,05). The results confirm the usefulness of the current practice of creating BCs by medical universities, medical institutes and regional chambers of physicians and dentists but rationalization of the workload for individual BCs is necessary.

随机控制实验:助推脱贫的现场干预研究

消除贫困是全世界新千年的首要目标。行为经济学家和发展经济学家正借助随机控制实验和助推技术在全球范围内帮助贫困者摆脱贫困。当前采用随机控制实验帮助贫困者克服行为偏差的助推行动主要表现在帮助贫困者改善当前物质条件和提升未来保障两个方面。随机控制实验和助推技术在国内的研究和实践也有效地帮助国内贫困农民提高了身心健康水平和经济收入。未来还需加强关于随机控制实验和助推技术的外部效度检验及两者的异同点方面的研究, 并结合脱贫的内生动力制定更加简单、高效、严谨的扶贫政策和项目。     

Comparing Cognitive Behavioral Therapy and Systemic Therapy for Social Anxiety Disorder: Randomized Controlled Pilot Trial (SOPHO-CBT/ST)

This randomized controlled trial (RCT) aimed to pilot the newly developed manualized and monitored systemic therapy (ST) for social anxiety disorder (SAD), as compared to manualized and monitored cognitive behavioral therapy (CBT). We conducted a prospective multicenter, assessor-blind pilot RCT on 38 outpatients (ICD F40.1; Structured Clinical Interview for DSM (SCID); Liebowitz Social Anxiety Scale, LSAS-SR >30). The primary outcome was level of social anxiety (LSAS-SR) at the end of treatment. A total of 252 persons were screened, and 38 patients were randomized and started therapy (CBT: 20 patients; ST: 18 patients; age: M = 36 years, SD = 14). Within-group, simple-effect intent-to-treat analyses (ITT) showed significant reduction in LSAS-SR (CBT:d = 1.04; ST:d = 1.67), while ITT mixed-design ANOVA demonstrated the advantage of ST (d = 0.81). Per-protocol analyses supported these results. Remission based on reliable change indices also demonstrated significant difference (LSAS-SR: 15% in CBT; 39% in ST;h: 0.550), supported by blind diagnosticians’ ratings of those who completed therapy (SCID; 45% in CBT, 78% in ST,p = .083). No adverse events were reported. CBT and ST both reduced social anxiety, supporting patient improvement with the newly developed ST for SAD; this has yet to be verified in a subsequent confirmatory RCT.     

Sudden Gains in Internet-Based Cognitive Behavior Therapy for Body Dysmorphic Disorder

Sudden gains have been associated with better short- and long-term treatment outcomes in a number of psychiatric disorders. However, no studies to date have evaluated sudden gains in body dysmorphic disorder (BDD). We used data from a previous randomized controlled trial evaluating the efficacy of an Internet-based cognitive-behavior treatment (CBT) for BDD. The sample consisted of 47 adults diagnosed with BDD. We compared the treatment outcomes of sudden gainers vs. gradual gainers (i.e., treatment responders with no sudden gains) and non-sudden gainers (i.e., gradual gainers plus nonresponders) at posttreatment and 3, 12, and 24 months after the end of the treatment. Twelve (25.5%) participants experienced a sudden gain. Compared to non-sudden gainers and to gradual gainers, sudden gainers showed significantly larger improvements on the Yale-Brown Obsessive-Compulsive Scale modified for BDD at posttreatment (g = 1.23 and g = .91, respectively), and at 3-month (g = 1.23 and g = 1.00, respectively), 12-month (g = 1.12 and g = .91, respectively), and 24-month follow-up (g = 1.11 and g = .97, respectively). This translated into higher rates of treatment responders and remitters in the sudden gainers across all time points. The occurrence of sudden gains in Internet-based CBT for BDD is associated with favorable short- and long-term treatment outcomes. This suggests that a sudden improvement during the treatment could be a marker of good prognosis, while non-sudden—including gradual—gainers are more likely to need continued support or booster sessions. Early identification of patients who are not progressing as expected and subsequent tailoring of the delivered intervention has the potential to improve treatment outcomes in this group.     

A randomized clinical trial of group and individual Cognitive-Behavioral Therapy approaches for Social Anxiety Disorder

To compare the effectiveness of two Cognitive-Behavioral Therapy (CBT) interventions—an individual and a group intervention—in Social Anxiety Disorder therapy. We compared the two treatment groups against a waitlist condition in a randomized clinical trial with 86 young adults. The individual CBT intervention was Trial-Based Cognitive Therapy (TBCT) developed by De-Oliveira, a novel technique in which the therapist engages the patient in a simulated judicial trial with the goal of identifying and changing core dysfunctional beliefs. The group intervention consisted of exposition therapy based on the Hofmann and Otto protocol (Group CBT) to restructure negative and dysfunctional cognitions regarding social situations. Both interventions reduced psychiatric symptoms from pre- to post-test and primary social anxiety and depression symptoms relative to waitlist controls. The interventions were recently introduced in Brazil, and this is the first randomized control trial to compare TBCT and this Group CBT, which were effective in assessing changes in social anxiety symptoms as well as co-occurring psychiatric symptoms.