On the relative contributions of positive reinforcement and escape extinction in the treatment of food refusal

We compared the effects of positive reinforcement alone, escape extinction alone, and positive reinforcement with escape extinction in the treatment of the food and fluid refusal of 4 children who had been diagnosed with a pediatric feeding disorder. Consumption did not increase when positive reinforcement was implemented alone. By contrast, consumption increased for all participants when escape extinction was implemented, independent of the presence or absence of positive reinforcement. However, the addition of positive reinforcement to escape extinction was associated with beneficial effects (e.g., greater decreases in negative vocalizations and inappropriate behavior) for some participants.     

Obstructive sleep apnea syndrome: autobiographical memory predicts the course of depressive affect after nCPAP therapy

Although nCPAP therapy has proven to be efficient at removing symptoms of obstructive sleep apnea syndrome (OSAS), recovery from depression frequently remains unsatisfactory. Other studies have shown that recall of autobiographical memories (AM) is a psychological vulnerability marker for depression, and also have shown its predictive power for the course of depression. It is therefore hypothesized that AM also predict the course of depressive affect in OSAS patients. Fifty-four consecutively admitted OSAS patients received standard nCPAP therapy. Specificity of AM assessed at the beginning of treatment was used as a predictor in a regression analysis, and the extent of recovery from depression over a follow-up period of between six to nine weeks served as the criterion variable. The results supported the hypothesis that patients who were able to recall more specific AM in response to positively valenced cue words showed a more substantial recovery from depression. This has important treatment implications.     

An ERP study of sensory mismatch expressions in Japanese

Combinations of different sensory words produce mismatch expressions like smooth color and red touch in contrast to normal expressions like red color and smooth touch. Concerning these sensory mismatch expressions, results of three experiments are reported. Experiment 1 revealed that (i) mismatch expressions were less comprehensible than normal expressions, and that (ii) there were two patterns among mismatch expressions: the high-comprehensible mismatch expression (HighCME, e.g., smooth color) and the low-comprehensible mismatch expression (LowCME, e.g., red touch). Experiment 2 revealed that the mismatch expressions produced a significantly greater N400 amplitude than the normal expressions. Experiment 3 implied that the difference between High/LowCME was reflected in a later latency band or in a topographical difference of N400, although the statistical significance was marginal. It is argued that the processes to integrate linguistic elements (e.g., combining adjectives and nouns) are not homogeneous.     

Septal infusions of glucose or pyruvate,but not fructose,produce avoidance deficits when co-infused with the GABA agonist muscimol

Although glucose typically enhances memory or reverses memory deficits, glucose can also produce memory deficits when co-infused with the gamma-aminobutyric acid (GABA) agonist muscimol into the medial septum (Parent & Gold, 1997; Parent, Laurey, Wilkniss, & Gold, 1997). To date the mechanisms underlying the memory-impairing interaction between GABA and glucose remain unknown. Here we investigate whether this effect is the result of hyperosmolar conditions or may involve glucose metabolism. Male Sprague-Dawley rats were given one-trial inhibitory avoidance training after receiving septal infusions of vehicle (phosphate-buffered saline, 0.5 microl), the GABA(A) agonist muscimol (3 nmol), glucose (16.5, 33, or 66 nmol), fructose (33 nmol), pyruvate (33 nmol), or a solution containing muscimol combined with glucose, fructose, or pyruvate. Retention performance was tested 48 h later. Infusions of glucose, pyruvate, fructose, or muscimol alone did not affect retention performance. However, co-infusions of all doses of glucose (16.5, 33, or 66 nmol) or the glycolytic end product pyruvate with muscimol impaired retention performance. Co-infusions of fructose with muscimol did not affect retention performance. These results suggest that the memory-impairing interaction between glucose and muscimol does not result from hyperosmolar conditions, because equiosmolar concentrations of fructose do not mimic the effects of glucose and the memory deficits do not vary as a function of glucose concentration. The finding that pyruvate mimicked the effects of glucose and impaired memory when combined with muscimol suggests that glucose metabolism may be involved in the memory-impairing interaction between glucose and GABA(A) receptors in the medial septum.     

Choice in a variable environment: effects of unequal reinforcer distributions

Six pigeons were trained in a procedure in which sessions included seven unsignaled components, each offering two pecking keys, and each providing a potentially different reinforcer ratio between the two keys. Across conditions, various combinations of reinforcer ratios and reinforcer-magnitude ratios were used to create unequal reinforcer distributions between the two alternatives when averaged across a session. The results extended previous research using the same basic procedure that had included only reinforcer distributions symmetrical around 1:1. Data analyses suggested that the variables controlling choice operated at a number of levels: First, individual reinforcers had local effects on choice; second, sequences of successive reinforcers obtained at the same alternative (continuations) had cumulative effects; and, third, when these sequences themselves occurred with greater frequency, their effects further cumulated. A reinforcer obtained at the other alternative following a sequence of continuations (a discontinuation) had a large effect and apparently reset choice to levels approximating the sessional reinforcer ratio.     

内隐自尊的稳定性--成败操纵对内隐自尊的影响

本研究以瑞文智力测验为成败操纵基本任务,对成败操纵前后、接受成功反馈和失败反馈的个体在内隐联想测验中的反应及其内隐自尊情况进行了分析研究,结果表明：(1)不论是接受成功反馈还是失败反馈,成败操纵后,被试的反应速度都显著地快于操纵前;(2)不论是接受成功反馈还是失败反馈,成败操纵后,被试的内隐自尊水平都显著地低于操纵前。内隐自尊易受即时的关于自我的情绪体验的影响,具有不稳定性,当个体兴奋水平、情绪唤醒水平较高,动机较为强烈时,内隐自尊作用将受到抑制。     

认知老化模型的研究

以２３２名２０－７９岁成人为被试和５项认知能力测验为指标,应用结构方程建模方法建立了认知老化模型。     

免疫性疾病治疗新途径：诱导细胞程序性死亡

免疫性疾病是一大类难治性的免疫紊乱而造成的疾病,尤其是自身免疫性疾病的一直困扰着免疫学家。传统的免疫治疗是根据不同疾病的需要增强免疫,调节免疫和抑制的方式进行,以辩证的观点分析免疫的增殖与程序性死亡这一对矛盾,认为：免疫性疾病的本质是免疫细胞增殖与程序性恨的失衡,因而通过诱导免疫细胞程序性死亡将成为免疫治疗的新途径。     

Exploratory Eye Movements to Pictures in Childhood-Onset Schizophrenia and Attention-Deficit/Hyperactivity Disorder (ADHD)

We investigated exploratory eye movements to thematic pictures in schizophrenic, attention-deficit/hyperactivity disorder (ADHD), and normal children. For each picture, children were asked three questions varying in amount of structure. We tested if schizophrenic children would stare or scan extensively and if their scan patterns were differentially affected by the question. Time spent viewing relevant and irrelevant regions, fixation duration (an estimate of processing rate), and distance between fixations (an estimate of breadth of attention) were measured. ADHD children showed a trend toward shorter fixations than normals on the question requiring the most detailed analysis. Schizophrenic children looked at fewer relevant, but not more irrelevant, regions than normals. They showed a tendency to stare more when asked to decide what was happening but not when asked to attend to specific regions. Thus, lower levels of visual attention (e.g., basic control of eye movements) were intact in schizophrenic children. In contrast, they had difficulty with top-down control of selective attention in the service of self-guided behavior.