Effects of reinforcement history on response rate and response pattern in periodic reinforcement

Several researchers have suggested that conditioning history may have long-term effects on fixed-interval performances of rats. To test this idea and to identify possible factors involved in temporal control development, groups of rats initially were exposed to different reinforcement schedules: continuous, fixed-time, and random-interval. Afterwards, half of the rats in each group were studied on a fixed-interval 30-s schedule of reinforcement and the other half on a fixed-interval 90-s schedule of reinforcement. No evidence of long-term effects attributable to conditioning history on either response output or response patterning was found; history effects were transitory. Different tendencies in trajectory across sessions were observed for measures of early and late responding within the interreinforcer interval, suggesting that temporal control is the result of two separate processes: one involved in response output and the other in time allocation of responding and not responding.     

Intervention Groups for Adolescents With Conduct Problems: Is Aggregation Harmful or Helpful?

Past research has suggested that the aggregation of deviant peers during treatment may cause harmful effects (T. J. Dishion, J. McCord, & F. Poulin, 1999). This study compared the effectiveness of problem-solving skills training groups in which all members had conduct problems (pure group condition) with groups that consisted of adolescents with and without behavior problems (mixed group condition). Participants were 139 sixth- and seventh-graders (mean age = 12.7; 63% male; 55% White) enrolled at public middle schools. Pre-, post-, and 6-month follow-up data were collected, along with intervention process variables. Results showed that, contrary to the deviancy training hypothesis, adolescents in the pure-group condition engaged in more adaptive in-session behavior and received lower scores on the parent and teacher ratings of externalizing behavior at postintervention than those in the mixed-group condition. Mediation analyses showed that the deviancy training that occurred in the mixed-group condition accounted for their worse postintervention scores, findings consistent with the deviancy training hypothesis.     

The Role of Temperament in the Etiology of Child Psychopathology

A substantial proportion of children and adolescents come to suffer from psychological disorders. This article focuses on the temperament factors that are involved in the pathogenesis of child psychopathology. It is argued that besides the reactive temperament factor of emotionality/neuroticism, the regulative process of effortful control also plays an important role in the etiology and maintenance of internalizing and externalizing problems in youths. More specifically, vulnerability to child psychopathology is determined by a temperament that is characterized by high levels of emotionality/neuroticism and low levels of effortful control. Models are hypothesized in which reactive and regulative temperament factors either have interactive or additive effects on the development of psychological disorders in children, and conceptualized in terms of a developmental psychopathology perspective. Directions for future research and clinical implications of this temperamental view on psychopathology are discussed.     

Measuring Impulsivity in School-Aged Boys and Examining Its Relationship with ADHD and ODD Ratings

Seven different laboratory measures of impulsivity were administered to a group of 165 school-aged boys. Parents' and teachers' ratings of Attention Deficit and Hyperactivity Disorder and Oppositional/Defiant Disorder were also obtained. Factor analyses of impulsivity measures revealed the existence of a strong Inhibitory Control Factor including measures derived from Stop Task, the Continuous Performance Test, the Matching Familiar Figures Test, and the Circle Tracing Task. Other forms of impulsivity like resistance to interference, the Wisconsin Card Sorting Test and efficiency in the DRL Task loaded on a second independent factor. The Inhibitory Control factor was correlated with ADHD ratings, whereas the second factor was slightly related to the presence of ODD symptoms. Discussion is focused on the relevance of inhibitory control in impulsivity and ADHD research.     

The necessity and the value of placebo

The use of placebo in clinical trials has been repeatedly challenged as being unacceptable from an ethical point of view. The present paper responds to this criticism by taking up the issue in the light of the pertinent provisions of the Helsinki Declaration. Examples from different therapeutic areas are given that highlight the importance of placebo in situations in which its use is acceptable according to the Declaration. Particular emphasis is given to the question of active control trials, which, under conditions of low assay sensitivity, may become an ethically less acceptable approach than the use of a placebo control. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003.     

Adjustment to chronic low back pain--the relative influence of fear-avoidance beliefs, catastrophizing, and appraisals of control

The present study investigated the relative extent to which patients' adjustment to chronic low back pain (CLBP) was influenced by their fear-avoidance beliefs, their tendency to catastrophize, and their appraisals of control. Eighty-three CLBP patients completed a series of self-report measures before participating in a physical therapist-led intervention. Hierarchical multiple regression analyses revealed that patients' perceptions of their ability to decrease pain explained a small, but statistically significant, proportion of the variance in pain intensity. In addition, patients' levels of catastrophizing, as well as their fear-avoidance beliefs about both work and physical activity, were independently associated with levels of disability. Interestingly, however, when exploring the relative predictive utility of these three psychological factors, it became evident that fear-avoidance beliefs about physical activity (FABs-PA) were the only significant predictor of patients' disability. Specifically, those patients who exhibited higher levels of FABs-PA tended to report greater levels of disability, even after adjusting for age, sex and pain intensity.     

Cognitive defusion and self-relevant negative thoughts: examining the impact of a ninety year old technique

Cognitive defusion techniques are designed to reduce the functions of thoughts by altering the context in which they occur, rather than the attempting to alter the form, frequency, or situational sensitivity of the thoughts themselves. Applied technologies designed to produce cognitive defusion seem to lead to reductions in the believability of negative thoughts, but defusion techniques are generally only parts of complex packages and the role of defusion techniques per se is note yet known. The present study examined the impact of a cognitive defusion technique first described by Titchener nearly 90 years ago: rapidly repeating a single word. In series of eight single-case alternating treatment designs, this defusion technique was compared to a distraction task, and to a thought control task on reductions in the discomfort and believability of self-relevant negative thoughts. The cognitive defusion technique reduced both discomfort and believability more so than the comparison approaches. Control studies showed that the effect was probably not due to demand characteristics.     

Changes in the structure of children's isometric force variability with practice

This study examined the effect of age and practice on the structure of children's force variability to test the information processing hypothesis that a reduction of sensorimotor system noise accounts in large part for age-related reductions in perceptual-motor performance variability. In the study, 6-year-olds, 10-year-olds, and young adults practiced on 5 consecutive days (15 trials/day), maintaining for 15-s trials a constant level of force (5 or 25% of maximum voluntary contraction) against an object using a pinch grip (thumb and index finger). With increasing age, the amount of force error and variability decreased, but the sequential structure of variability increased in irregularity. With practice, children reduced the amount of variability by changing the structure of the force output so as to be more similar to that of their older counterparts. The findings provide further evidence that practice-driven changes in the structure of force output, rather than a decline in the amount of white noise, largely account for age-related reductions in the amount of force variability.     

The planning and execution of sequential eye movements: saccades do not show the one target advantage

The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.     

The multiple meanings of secondary gain

The historical development of the concept of secondary gain is described in this article. Freud introduced this concept as a complement to primary gain. Freud modified the scope of both concepts during his career, but they remained within the boundary of an intrapsychological mechanism. Outside psychoanalysis, the concept of secondary gain has acquired further meaning with higher emphasis on interpersonal and social aspects. Consequently, it is often unclear what a writer or speaker means when he uses the term secondary gain. The different meanings of secondary gain in and outside psychoanalysis are illustrated with reference to literature and case reports.