A comparison of multiple reinforcer assessments to identify the function of maladaptive behavior

Functional analysis results indicated that maladaptive behaviors displayed by a 25-year-old man with profound mental retardation were maintained by attention from caregivers and possibly, to a lesser degree, by access to tangible items. A concurrent-schedules procedure was then used to study the relative reinforcing value for maladaptive behavior of attention versus tangible items. Results of the concurrent-schedules assessment and subsequent functional communication training indicated that preference for attention versus access to a tangible object varied.     

Drug discrimination under concurrent variable-ratio variable-ratio schedules

Pigeons were trained to discriminate 5 mg/kg pentobarbital from saline under concurrent variable-ratio (VR) VR schedules, in which responses on the pentobarbital-biased lever were reinforced under the VR schedule with the smaller response requirements when pentobarbital was given before the session, and responses on the saline-biased key were reinforced under the VR schedule with the larger response requirements. When saline was administered before the session, the reinforcement contingencies associated with the two response keys were reversed. When responding stabilized under concurrent VR 20 VR 30, concurrent VR 10 VR 40, or concurrent VR 5 VR 50 schedules, pigeons responded almost exclusively on the key on which fewer responses were required to produce the reinforcer. When other doses of pentobarbital and other drugs were substituted for the training dose, low doses of all drugs produced responding on the saline-biased key. Higher doses of pentobarbital and chlordiazepoxide produced responding only on the pentobarbital-biased key, whereas higher doses of ethanol and phencyclidine produced responding only on this key less often. d-Amphetamine produced responding primarily on the saline-biased key. When drugs generalized to pentobarbital, the shape of the generalization curve under concurrent VR VR schedules was more often graded than quantal in shape. Thus, drug discrimination can be established under concurrent VR VR schedules, but the shapes of drug-discrimination dose-response curves under concurrent VR VR schedules more closely resemble those seen under interval schedules than those seen under fixed-ratio schedules. Graded dose-response curves under concurrent VR VR schedules may relate to probability matching and difficulty in discriminating differences in reinforcement frequency.     

An examination of the response styles theory of depression in third- and seventh-grade children: a short-term longitudinal study

The goal of this study was to test the response styles theory of depression in a sample of 3rd- and 7th-grade children. In addition, we examined whether the relationship between rumination and increases in depressive symptoms is mediated by hopelessness and low self-esteem. The procedure involved an initial assessment in which depressive symptoms, response styles, hopelessness, and self-esteem were assessed. The procedure also involved a follow-up assessment, 6 weeks later, in which depressive symptoms, hopelessness, and self-esteem were reassessed. Children with a ruminative response style exhibited increases in depressive symptoms over the 6-week period. In addition, the relationship between rumination and increases in depressive symptoms was mediated by both hopelessness and low self-esteem. Last, contrary to our hypotheses, neither distraction nor problem-solving response styles predicted decreases in depressive symptoms over the course of the study.     

Lapses of intention and performance variability reveal age-related increases in fluctuations of executive control

We examine the hypothesis that the efficiency of executive control processes is less stable over time in older than younger adults. An age-related decrease in the efficiency of executive control should result in an increase in performance variability in task conditions requiring the recruitment of executive control processes and not in task conditions requiring minimal involvement of executive control. Performance variability was similar for younger and older adults in task conditions requiring minimal executive control and greater for older than younger adults in task conditions requiring executive control. These and other data are consistent with the proposal that aging is associated with a decrease in the stability of executive control over time.     

中国大学生的记忆的自我参照效应

记忆的自我参照效应是指记忆材料与自我相联系时的记忆效果优于其它编码条件的现象,这种优势主要体现在以回忆经验为特征的R反应(“记得”)上。西方一些研究表明,自我参照的记忆成绩优于参照母亲的记忆。本研究以中国大学生为被试,得到参照父亲和母亲的记忆与自我参照有同样好的成绩,显著优于参照名人的记忆,并且父母之间无差异。这支持了独立型／依赖型自我概念模型中的东方文化下的自我概念包括父母的观点。     

Reinforcing variability in adolescents with autism

Five adolescents with autism, 5 adult control participants, and 4 child controls received rewards for varying their sequences of responses while playing a computer game. In preceding and following phases, rewards were provided at approximately the same rate but were independent of variability. The most important finding was that, when reinforced, variability increased significantly in all groups. Reinforced variability could provide the necessary behavioral substrate for individuals with autism to learn new responses.     

Further evaluation of low-ranked items in stimulus-choice preference assessments

The generality of the findings reported by DeLeon, Iwata, and Roscoe (1997) was examined by conducting two stimulus-choice preference assessments, the second of which evaluated low-ranked items from the initial assessment. Results for the 2 participants suggested that supplementary assessments of low-ranked items may be useful for identifying a wider variety of reinforcing stimuli.     

Hyperactivity in Children: A Focus on Genetic Research and Psychological Theories

Hyperactivity has attracted a large amount of research interest in recent years. Here we review developments in genetic research and in research testing psychological theories of the condition. Family, adoptee and twin studies indicate a strong role for genetic factors in the etiology of hyperactivity. Evidence is emerging also from molecular genetic studies, implicating specific genes that may be involved. At the level of cognitive functioning, a divided, focused or sustained attention deficit does not seem to be a core deficit in hyperactivity. Although children with hyperactivity often perform poorly on certain executive function tasks, there is disagreement about the interpretation of these findings. The association reported in some studies between a slow inhibitory process and hyperactivity may reflect a generally slow, variable in speed and inaccurate pattern of responding. Hypotheses about psychological mechanisms such as state regulation or delay aversion provide alternative, and particularly encouraging, interpretations of the findings. We discuss the possible integration of the two lines of research—those of genetic research and research on psychological mechanisms.     

An evaluation of a brief multiple-stimulus preference assessment with adolescents with emotional-behavioral disorders in an educational setting

Brief multiple-stimulus-without-replacement (MSWO) preference assessments were conducted with 3 adolescent boys with emotional-behavioral disorders in the context of their public school educational program. The reinforcing effects of stimuli identified as high, medium, and low preference were then evaluated using an alternating treatments design in which, following an initial baseline, stimuli were delivered contingent on on-task behavior. High-preference stimuli produced the highest percentages of on-task behavior for all 3 participants.     

Use of a lag differential reinforcement contingency to increase varied selections of classroom activities

The present study evaluated the effects of a lag differential reinforcement contingency on 2 students' activity selections using reversal designs. Results showed that the lag contingency was responsible for promoting increased novel selections, engagement in diverse activities, and greater progress with respect to programmed academic activities.