Hazard function effects on promoting self-control in variable interval time-based interventions in rats

The present experiments investigated properties of time-based interventions used to increase self-control. Rats received impulsive-choice assessments before and after interventions that consisted of different distributions of delays to reinforcement. In Experiment 1, rats received an intervention with an increasing hazard function where delays were more evenly distributed, a decreasing hazard function where delays were mostly short, or a constant hazard function where delays were exponentially distributed. Surprisingly, rats that received the decreasing hazard function made the most self-controlled choices. Response rates during intervention trials showed that rats anticipated reinforcement based on the shape of the distributions they received. In Experiment 2, rats received an intervention with a decreasing hazard function with a steep slope or a shallow slope. Both time-based interventions increased self-control and produced similar response-rate patterns, indicating that the slope of the decreasing hazard function may not play a strong role in intervention efficacy. While this research aligns with previous literature showing that time-based interventions improved self-control, exposure to short delays produced the biggest improvements. Ultimately, exposure to short delays may increase the subjective value of the larger–later choice while occasional long delays may promote the ability to wait, which may have important implications for translational applications.     

Immediate postsession feeding reduces operant responding in rats

Three experiments investigated the effects of immediate and delayed postsession feeding on progressive-ratio and variable-interval schedule performance in rats. During Experiments 1 and 2, immediate postsession feeding decreased the breakpoint, or largest completed ratio, under progressive-ratio schedules. Experiment 3 was conducted to extend the results of the first two experiments to responding maintained by variable-interval schedules with different session lengths (15 and 60 min). Response rates decreased in all 4 subjects when postsession feeding immediately followed a 15-min session and in 3 of 4 subjects when postsession feeding immediately followed a 60-min session. The implications of this research are twofold: (1) The functional context in which within-session reinforcers are embedded extends outside the experimental chamber, and (2) supplemental postsession feedings should be sufficiently delayed from the end of a session to avoid weakening operant behavior in the experimental sessions.     

Optimal behavior and concurrent variable ratio-variable interval schedules

Concurrent variable ratio-variable interval (CONC VRVI) schedules of reinforcement, and the time-based analog of the same schedule (CONC VT*VT), have been used to determine if the matching law accounts for the distribution of choices between the behavior alternatives more accurately than the assumption that subjects distribute time between the alternatives to maximize total reinforcement rate. The results of those experiments leave room for interpretation. One problem is the lack of understanding of the theoretical outcomes associated with maximization in these schedules. A precise understanding of the characteristics of optimal behavior (OB) could help identify experimental evidence of OB. Here we derive equations that describe the optimal times the subject should spend on each alternative of the schedule. We provide a table of the optimal times for a wide range of parameter values of the schedule that experimenters can use to compare easily experimental results to the results expected if subjects behave optimally. We also derive a function m that relates matching and optimal performance and we prove interesting characteristics of the function. Finally, we describe features of OB with CONC VT*VT and with concurrent variable time schedules that can be used to identify evidence of OB.     

关于大学生心理障碍干预模式的理论建构

本文在已有研究的基础上,根据大学生心理发展与心理素质的特点和不同心理学派的理论观点建构了大学生心理障碍干预模式,该模式由多维系统的干预途径、多样渗透的干预方法、丰富全面的干预工作内容和完善化人性化的干预机制组成,它们之间的关系既是独立的,又是相互协调和影响的。体现了大学生心理障碍干预模式的系统完整性及实施干预的灵活多样性和明确针对性。     

A stronger latent‐variable methodology to actual–ideal discrepancy

We introduce a latent actual–ideal discrepancy (LAID) approach based on structural equation models (SEMs) with multiple indicators and empirically weighted variables. In Study 1, we demonstrate with simulated data, the superiority of a weighted approach to discrepancy in comparison to a classic unweighted one. In Study 2, we evaluate the effects of actual and ideal appearance on physical self‐concept and self‐esteem. Actual appearance contributes positively to physical self‐concept and self‐esteem, whereas ideal appearance contributes negatively. In support of multidimensional perspective, actual‐ and ideal‐appearance effects on self‐esteem are substantially—but not completely—mediated by physical self‐concept. Whereas this pattern of results generalises across gender and age, multiple‐group invariance tests show that the effect of actual appearance on physical self‐concept is larger for women than for men. Copyright © 2008 John Wiley & Sons, Ltd.     

Do fish count? Spontaneous discrimination of quantity in female mosquitofish

The spontaneous tendency to join the largest social group was used to investigate quantity discrimination in fish. Fish discriminated between shoals that differed by one element when the paired numbers were 1vs2, 2vs3 and 3vs4, but not when 4vs5 or larger. Using large numerosities (>4), the ability to discriminate between two numbers improved as the numerical distance between them increased and a significant discrimination was found only with ratios of 1:2 or smaller (4vs8, 8vs16 and 4vs10). Experiments to control for non-numerical variables evidenced the role played by the total area of stimuli with both large and small numerosities; the total quantity of movement of the fish within a shoal appeared also important but only when large numerosities were involved. Even though the pattern of discrimination exhibited by female mosquitofish is not fully consistent with any of the existing models of quantity representation, our results seem to suggest two distinct mechanisms in fish, one used to compare small numbers of objects and one used when larger numerosities are involved.     

Optimal behavior and concurrent variable interval schedules

Behavior maintained with 2-component concurrent variable interval schedules of reinforcement (CONC VIVI) is described well by the matching law. Deviations from matching behavior have been handled by adding free parameters to the matching law equation. With CONC VIVI schedules there are infinitely many solutions to the matching law equation at each value of the procedural parameters. However, at each value of the procedural parameters, only one combination of durations of intervals spent in each VI component (dwell times) yields the combined maximum reinforcement rate. The equations that yield the optimal dwell times solution for CONC VIVI schedules are mathematically incompatible with the matching law. Optimal performance and matching coincide only when the parameter values of the two VI components are equal. It seems reasonable to use optimal behavior to assess performance in these schedules. Researchers have not compared optimal and empirical performances in CONC VIVI possibly because the equations for optimal dwell times (ODT) can be solved only numerically. We present a table of ODT for a wide range of VIs and changeover delays. We also derive a function m that can be used to compare matching data and the matching behavior predictions of optimization. We prove that 0.5<m<1.003502, and we describe some of the more nteresting properties of the function.     

教师压力影响职业倦怠:教学效能感的调节作用

采用问卷法以743名中小学在职教师为被试研究了教学效能感在职业压力影响职业倦怠过程中的调节作用。结果发现:①教师的工作特征、学生等压力源能有效预测教师职业倦怠。随着从业年限的增加,影响职业倦怠的主要压力源从工作特征过渡到社会特征。②教学效能的调节作用因教师不同的人口学分布而异,其中一般教学效能和个体教学效能所表现出来的调节效应也不同。③个体教学效能表现出线性调节作用,一般教学效能表现出曲线调节作用,两种调节作用的性质取决于不同的压力源。     

初二学生的科学观及其与科学发现学习的关系

该研究旨在通过问卷法和实验法考察初二学生在自然科学领域中的认识论观念及其对学习过程和策略的影响.研究一发现,在科学的动态性、有限性、客观性、理论价值取向、公众性以及对科学的态度兴趣等六种基本观念上,初二学生总体上持有较混合的看法;对科学的积极态度与学习者的物理学习成绩相关显著.研究二考察了科学观对科学发现学习的影响.科学的公众性观念与灵活应用测验成绩相关显著,科学的客观性观念及智力水平对科学发现学习中的控制性实验策略有重要影响.