分数的数量表征

分数数量表征已成为当前数学认知研究的重要主题之一。基于该领域近10年来的研究发现, 总结了分数数量表征研究的新进展。首先概述分数数量表征的发展, 然后着重介绍分数数量的不同表征方式并系统分析制约数量表征的任务及背景因素。此外, 还深入探究了分数数量表征与整数、小数数量表征的区别与联系。未来研究者应注意在分数数量表征的个体差异、跨文化以及干预等方面加强考察。     

焦虑情绪对奖赏学习的影响

焦虑是在我们日常生活中占据重要地位的一种情绪, 对人类的决策行为能够产生显著影响。探讨决策研究的重要领域--奖赏学习, 可以帮助我们更深入地认识焦虑情绪在决策过程中扮演的角色。过往研究者较少关注焦虑对奖赏学习的潜在影响, 而且已有研究在实验技术和任务范式方面存在一定的局限性。考虑到奖赏学习概念的复杂性, 为了全面地考察个体焦虑水平与奖赏学习的关系, 本文作者建议设置不同类型的奖赏学习情境, 例如概率学习、联结学习、逆向学习和社会学习等。在上述各类不同任务中, 个体焦虑水平对奖赏学习能力的影响模式可能并不一致, 有待研究者们进行深入探讨。     

Cooperative Learning Groups at the College Level: Differential Effects on High, Average, and Low Exam Performers

A repeated-measures mixed-design was used in examining the effects of cooperative learning study teams on exam performance for 378 undergraduate students enrolled in one of 10 large sections of an introductory educational psychology course over a two-semester period. Students were assigned to 5-member cooperative groups based on previous exam achievement (low, average, high). Bonuses (20% of exam score) were offered to groups who improved their mean exam performance to a pre-established criterion in the cooperative-group phase. Results yielded an overall effect size of 0.42 for cooperative study versus individual study. Students who had obtained low and average scores on the preceding exam improved significantly during cooperative study, but the previously high achievers decreased somewhat.     

Fluent Reading as the Improvement of Stimulus Control: Additive Effects of Performance-Based Interventions to Repeated Reading on Students' Reading and Error Rates

The impact of adding performance-based interventions to a skill-based intervention on oral reading fluency was examined with 3 elementary students identified as having difficulty with reading. Two performance-based interventions were combined with the skill-based intervention Repeated Reading (RR) to create the three instructional packages investigated. The packages included Repeated Readings (RR), Repeated Readings with Performance Feedback (RR/FB), and Repeated Readings with Performance Feedback and Contingent Reward (RR/FB/REW). Results suggested that Repeated Reading (RR) alone led to the greatest increase in reading fluency for participants with the highest reading rates and lowest error rates at baseline. In contrast, the participant who exhibited the lowest reading rate and highest error rate benefited the most when Repeated Readings was offered in conjunction with Performance Feedback (RR/FB) or Performance Feedback plus Contingent Reward (RR/FB/RW). Implications for blending skill- and performance-based interventions to develop stimulus control over fluent reading and future research directions are discussed.     

Typical and atypical development of basic numerical skills in elementary school

Deficits in basic numerical processing have been identified as a central and potentially causal problem in developmental dyscalculia; however, so far not much is known about the typical and atypical development of such skills. This study assessed basic number skills cross-sectionally in 262 typically developing and 51 dyscalculic children in Grades 2, 3, and 4. Findings indicate that the efficiency of number processing improves over time and that dyscalculic children are generally less efficient than children with typical development. For children with typical arithmetic development, robust effects of numerical distance, size congruity, and compatibility of ten and unit digits in two-digit numbers could be identified as early as the end of Grade 2. Only the distance effect for comparing symbolic representations of numerosities changed developmentally. Dyscalculic children did not show a size congruity effect but showed a more marked compatibility effect for two-digit numbers. We did not find strong evidence that dyscalculic children process numbers qualitatively differently from children with typical arithmetic development.     

Preschoolers’ nonsymbolic arithmetic with large sets: Is addition more accurate than subtraction?

Adult and developing humans share with other animals analog magnitude representations of number that support nonsymbolic arithmetic with large sets. This experiment tested the hypothesis that such representations may be more accurate for addition than for subtraction in children as young as 3½ years of age. In these tasks, the experimenter hid two equal sets of cookies, visibly added to or subtracted from the sets, and then asked 3½-year-olds which set had more cookies. Initial set size was either large (7 or 9) or very large (18 or 30), and the final sets differed by either a high proportion (ratio of 1:2) or a low proportion (difference of 1 cookie). Children’s addition performance exceeded chance, as well as their subtraction performance, across set sizes and proportions, whereas subtraction performance did not exceed chance. Arithmetic performance was also independent of counting ability. Addition performance was remarkably accurate when ratios between outcomes were close to 1, in contrast to previous findings. Interpretations for the asymmetry between addition and subtraction are discussed with respect to the nature of representations for nonsymbolic arithmetic with large sets.     

Children’s early mental number line: Logarithmic or decomposed linear?

Recently, the nature of children’s mental number line has received much investigation. In the number line task, children are required to mark a presented number on a physical number line with fixed endpoints. Typically, it was observed that the estimations of younger/inexperienced children were accounted for best by a logarithmic function, whereas those of older/more experienced children were reflected best by a linear function. This led to the conclusion that children’s mental number line transforms from logarithmic to linear with age and experience. In this study, we outline an alternative interpretation of children’s performance in a number line task. We suggest that two separate linear representations for one- and two-digit numbers may exist in young children and that initially the integration of these two representations into the place value structure of the Arabic number system is not fully mastered. When testing this assumption in a sample of more than 120 first graders, we observed that the two-linear model consistently provided better fit indexes. We conclude that instead of assuming a transition from logarithmic to linear coding, performance differences could also be accounted for by an improvement in integrating tens and units into the Arabic place value system.     

Reward value effects on timing in the peak procedure

Three experiments examined the effect of motivational variables on timing in the peak procedure. In Experiment 1, rats received a 60-s peak procedure that was coupled with long-term, between-phase changes in reinforcer magnitude. Increases in reinforcer magnitude produced a leftward shift in the peak that persisted for 20 sessions of training. In a final phase, the rats received lithium chloride-induced aversion prior to testing and a rightward shift in the peak was observed. Experiment 2 confirmed the rightward shift in the peak under lithium chloride devaluation and induced a comparable shift with satiety devaluation. The degree of rightward shift was neither additive nor multiplicative, suggesting that two processes may have contributed. Experiment 3 examined the effect of extinction on peak responding, revealing a decrease in response rate, but no evidence of any change in the timing of responding. The implications of the results for contemporary timing theories are discussed.     

决策中损益值大小效应的发生条件及机制再探 —— 一种齐当别视角及兼对视角本身的一些探讨

通过两个研究,损益值大小效应在1元~1亿元的广阔范围内,以及在只采用选择反应模式的条件下得到了进一步探讨,其机制也在齐当别模型的全新视角下得到了讨论;此外,齐当别模型本身以及模型的经典判断任务也得到了探讨。结果发现：基于选择反应模式时,损益值大小效应在获得情景中稳定存在,并只存在一个风险倾向的拐点,而它在损失情景中则不存在;损益值大小效应的机制能够被齐当别模型很好的解释;齐当别模型的经典判断任务对模型预测效能的检验力不足,但其与新设计的维度内判断任务联合后却有很大改善;齐当别模型对损失情景中的均含0结果值的决策任务的解释力还有待进一步探讨     

海洛因戒断者对金钱奖赏的反馈加工异常：来自ERP的证据

本研究采用金钱奖赏延迟任务考察了海洛因戒断者对金钱奖赏和损失的预期和反馈加工及其电生理机制。结果发现,预期阶段两组被试由不同线索诱发的P3波幅不存在显著差异。在金钱奖赏加工的反馈阶段,海洛因戒断组由金钱收益条件诱发的RewP波幅显著小于对照组由金钱收益条件诱发的RewP波幅,而在无收益无损失条件下两组被试诱发的RewP波幅不存在显著差异。此外,海洛因戒断组由金钱收益条件诱发的P3波幅与无收益无损失条件诱发的P3波幅不存在显著差异,而对照组由金钱收益条件诱发的P3波幅显著大于其由无收益无损失条件诱发的P3波幅。在金钱损失加工的反馈阶段,由金钱损失和无收益无损失条件诱发的RewP波幅在两组被试之间不存在显著差异,且两组被试由金钱损失条件诱发的P3波幅均显著大于其由无收益无损失条件诱发的P3波幅。以上结果说明海洛因戒断者对金钱奖赏的反馈加工存在异常,具体表现为其对金钱奖赏的敏感性降低或对金钱奖赏的趋近动机减弱。