Response to commentaries on discussion paper Gene–environment interdependence

There is a high measure of agreement on the key issues concerning gene–environment interdependence. Contrary to arguments on the need for direct exact replication of findings, it is suggested that “robust” replication using the same constructs is needed. RCTs have an important role for testing for environmental mediation but cannot be used for environmental risks in childhood that show G×E in relation to adult outcomes. Instead, greater use needs to be made of natural experiments. Experimental methods are needed to study biological mediating mechanisms and these should include both animal models and human brain imaging studies. In addition to further research on G×E, further studies of gene–environment correlations are required. Many challenges remain but the future for gene–environment interdependence is bright.     

Analysis of Recruitment Strategies: Enrolling Veterans With PTSD Into a Clinical Trial

This analysis evaluated the efficacy of a variety of recruitment methods employed in a medication trial in a veteran population. Recruitment and demographic data were collected over the course of a randomized controlled trial (RCT) assessing the efficacy of an experimental medication for posttraumatic stress disorder (PTSD). Multivariate logistic regression was used to identify demographic and recruitment variables predictive of consenting to participation in the trial. Data were collected for 1,050 potential study participants. As compared with individuals contacted by mail based on chart review, potential participants who were referred by a clinician were 3 times more likely to consent to participate, and individuals who responded to an advertisement were 5 times more likely to consent to participate. Females were more likely to respond to advertisements, whereas males were more likely to be referred. Those who were referred were significantly older than potential participants identified via the directed mailing. Clinician referral was the method most likely to lead to identifying an eligible and willing participant. When designing a recruitment plan for a clinical trial, factors such as the target sample and available staff should be carefully considered.     

Applying Behavioral Momentum Theory to Increase Compliance

ABSTRACT

Behavioral momentum has been used as a theory to create effective interventions to increase compliance with requests, including student compliance in schools. These interventions are based on delivering a series of high probability compliance request-response-reinforcement (RRR) trials at high rates just prior to providing a request for a response that has often resulted in noncompliance. In this article, a real example of a substitute teacher leading her class through the Hokey-Pokey is used to describe and clarify interventions based on behavioral momentum. Analysis of specific procedural variables that may impact the effectiveness of interventions based on behavioral momentum theory is provided to assist practitioners with development and implementation of these proce dures within educational contexts. Recommendations for future research on this innovative technology areprovided.     

Is Measurement Noninvariance a Threat to Inferences Drawn from Randomized Control Trials? Evidence From Empirical and Simulation Studies

Randomized control trials (RCTs) are considered the gold standard when evaluating the impact of psychological interventions, educational programs, and other treatments on outcomes of interest. However, few studies consider whether forms of measurement bias like noninvariance might impact estimated treatment effects from RCTs. Such bias may be more likely to occur when survey scales are utilized in studies and evaluations in ways not supported by validation evidence, which occurs in practice. This study consists of simulation and empirical studies examining whether measurement noninvariance impacts treatment effects from RCTs. Simulation study results demonstrate that bias in treatment effect estimates is mild when the noninvariance occurs between subgroups (e.g., male and female participants), but can be quite substantial when being assigned to control or treatment induces the noninvariance. Results from the empirical study show that surveys used in two federally funded evaluations of educational programs were noninvariant across student age groups.     

USING A BLOCKED-TRIALS PROCEDURE TO TEACH IDENTITY MATCHING TO A CHILD WITH AUTISM

Children with autism may struggle in developing conditional discrimination repertoires. Saunders and Spradlin (1989 , 1990 , 1993 ) arranged “blocked” teaching trials in which they presented the same sample stimulus repeatedly across trials (in lieu of randomly alternating targets across trials) and then faded the number of trials in each block. We replicated the effects of this blocked‐trials procedure in teaching identity matching to a child with autism and evaluated the necessity of fading. Arranging blocked trials facilitated the acquisition of identity matching, but fading the block size was not necessary to maintain discriminated performance.     

Color preference in pigeons: stimulus intensity and reinforcement contingency effects in the avoidance of blue stimuli.

In a procedure intended to determine color preference in pigeons (which partially replicated Catania, Owens, & von Lossberg, 1983), two keys were illuminated by different colors drawn from a set of amber, red, green, or blue stimuli; this was followed by the presentation of grain when either of the two colors was pecked. The grain was illuminated alternately across trials with the colors presented on the keys. In Experiment 1 the intensity of the color stimuli used was not equalized, whereas in Experiment 2 the intensity of the colors was equalized. The low preference for blue found in Experiment 1, as measured by differential key pecking, was not found in Experiment 2. The discriminability of the intensity-equalized colors was confirmed in Experiment 2a, in which equal-intensity color discrimination problems were presented. In Experiment 3, as in Catania et al. (1983), a response-independent reinforcement schedule was used, but with intensity-equalized colors. In contrast to Experiment 2, very low preference for blue was found here and in Experiment 4, which used a within-subject procedure. These findings suggest that pigeon color preference may be a function of intensity, but all controlling variables have not as yet been identified.     

Some Effects Of Intertrial Interval Duration On Discrete-trial Choice

Pigeons were trained in Experiment 1 on a discrete-trial concurrent variable-interval (VI) 1-min VI 3-min schedule, and in Experiment 2 on a discrete-trial concurrent VI 1.5-min VI 1.5-min schedule. In each experiment, the intertrial-interval durations (ITIs) were 0 s, 6 s, 22 s, and 120 s, and the schedules were both independent and interdependent. The purpose of the research was to determine whether lengthening the ITI would disrupt any local control that existed, measured with respect to relative response rate and changeover probability. In Experiment 1, with the independent schedules, both preference and obtained relative reinforcement rate approximated .75 at short ITIs, but then decreased toward .50 with longer ITIs. With interdependent schedules, both preference and obtained relative reinforcement rate approximated .75 at all ITIs. In both experiments, with both independent and interdependent schedules, changeover probabilities for each response in a sequence of up to five successive responses to a given schedule were variable for individual birds. The average changeover probabilities for all birds suggested perseveration rather than a systematic increase within a given ITI or a systematic trend toward chance responding as ITI duration increased. Finally, the changeover functions did not differ when a sequence of responses was calculated to begin anew after reinforcement rather than with the first response on a schedule. Taken together, the data were inconsistent with a theory holding that only local processes underlie choice in discrete-trial procedures.     

Transference focused psychotherapy: overview and update

This paper describes a specific psychoanalytic psychotherapy for patients with severe personality disorders, its technical approach and specific research projects establishing empirical evidence supporting its efficacy. This treatment derives from the findings of the Menninger Foundation Psychotherapy Research project, and applies a model of contemporary psychoanalytic object relations theory as its theoretical foundation. The paper differentiates this treatment from alternative psychoanalytic approaches, including other types of psychoanalytic psychotherapy as well as standard psychoanalysis, and from three alternative non-analytical treatments prevalent in the treatment of borderline patients, namely, dialectic behavior therapy, supportive psychotherapy based on psychoanalytic theory, and schema focused therapy. It concludes with indications and contraindications to this particular therapeutic approach derived from the clinical experience that evolved in the course of the sequence of research projects leading to the empirical establishment of its efficacy.     

Sham surgery: An ethical analysis

Surgical clinical trials have seldom used a "sham" or placebo surgical procedure as a control, owing to ethical concerns. Recently, several ethical commentators have argued that sham surgery is either inherently or presumptively unethical. In this article I contend that these arguments are mistaken, and that there are no sound ethical reasons for an absolute prohibition of sham surgery in clinical trials. Reflecting on three cases of sham surgery, especially on the recently reported results of a sham-controlled trial of arthroscopic surgery for arthritis of the knee, I present an ethical analysis that focuses on the methodological rationale for use of sham surgery, risk-benefit assessment, and informed consent.